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
 276         err = register_netdevice(dev);
 277         if (err < 0)
 278                 goto out;
 279
 280         strcpy(t->parms.name, dev->name);
 281         dev->rtnl_link_ops = &ip6_link_ops;
 282
 283         dev_hold(dev);
 284         ip6_tnl_link(ip6n, t);
 285         return 0;
 286
 287 out:
 288         return err;
 289 }
 290
 291 /**
 292  * ip6_tnl_create - create a new tunnel
 293  *   @p: tunnel parameters
 294  *   @pt: pointer to new tunnel
 295  *
 296  * Description:
 297  *   Create tunnel matching given parameters.
 298  *
 299  * Return:
 300  *   created tunnel or NULL
 301  **/
 302
 303 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
 304 {
 305         struct net_device *dev;
 306         struct ip6_tnl *t;
 307         char name[IFNAMSIZ];
 308         int err;
 309
 310         if (p->name[0])
 311                 strlcpy(name, p->name, IFNAMSIZ);
 312         else
 313                 sprintf(name, "ip6tnl%%d");
 314
 315         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 316                            ip6_tnl_dev_setup);
 317         if (dev == NULL)
 318                 goto failed;
 319
 320         dev_net_set(dev, net);
 321
 322         t = netdev_priv(dev);
 323         t->parms = *p;
 324         t->net = dev_net(dev);
 325         err = ip6_tnl_create2(dev);
 326         if (err < 0)
 327                 goto failed_free;
 328
 329         return t;
 330
 331 failed_free:
 332         ip6_dev_free(dev);
 333 failed:
 334         return NULL;
 335 }
 336
 337 /**
 338  * ip6_tnl_locate - find or create tunnel matching given parameters
 339  *   @p: tunnel parameters
 340  *   @create: != 0 if allowed to create new tunnel if no match found
 341  *
 342  * Description:
 343  *   ip6_tnl_locate() first tries to locate an existing tunnel
 344  *   based on @parms. If this is unsuccessful, but @create is set a new
 345  *   tunnel device is created and registered for use.
 346  *
 347  * Return:
 348  *   matching tunnel or NULL
 349  **/
 350
 351 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
 352                 struct __ip6_tnl_parm *p, int create)
 353 {
 354         const struct in6_addr *remote = &p->raddr;
 355         const struct in6_addr *local = &p->laddr;
 356         struct ip6_tnl __rcu **tp;
 357         struct ip6_tnl *t;
 358         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 359
 360         for (tp = ip6_tnl_bucket(ip6n, p);
 361              (t = rtnl_dereference(*tp)) != NULL;
 362              tp = &t->next) {
 363                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 364                     ipv6_addr_equal(remote, &t->parms.raddr)) {
 365                         if (create)
 366                                 return NULL;
 367
 368                         return t;
 369                 }
 370         }
 371         if (!create)
 372                 return NULL;
 373         return ip6_tnl_create(net, p);
 374 }
 375
 376 /**
 377  * ip6_tnl_dev_uninit - tunnel device uninitializer
 378  *   @dev: the device to be destroyed
 379  *
 380  * Description:
 381  *   ip6_tnl_dev_uninit() removes tunnel from its list
 382  **/
 383
 384 static void
 385 ip6_tnl_dev_uninit(struct net_device *dev)
 386 {
 387         struct ip6_tnl *t = netdev_priv(dev);
 388         struct net *net = t->net;
 389         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 390
 391         if (dev == ip6n->fb_tnl_dev)
 392                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
 393         else
 394                 ip6_tnl_unlink(ip6n, t);
 395         ip6_tnl_dst_reset(t);
 396         dev_put(dev);
 397 }
 398
 399 /**
 400  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
 401  *   @skb: received socket buffer
 402  *
 403  * Return:
 404  *   0 if none was found,
 405  *   else index to encapsulation limit
 406  **/
 407
 408 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
 409 {
 410         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) raw;
 411         __u8 nexthdr = ipv6h->nexthdr;
 412         __u16 off = sizeof(*ipv6h);
 413
 414         while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
 415                 __u16 optlen = 0;
 416                 struct ipv6_opt_hdr *hdr;
 417                 if (raw + off + sizeof(*hdr) > skb->data &&
 418                     !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr)))
 419                         break;
 420
 421                 hdr = (struct ipv6_opt_hdr *) (raw + off);
 422                 if (nexthdr == NEXTHDR_FRAGMENT) {
 423                         struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
 424                         if (frag_hdr->frag_off)
 425                                 break;
 426                         optlen = 8;
 427                 } else if (nexthdr == NEXTHDR_AUTH) {
 428                         optlen = (hdr->hdrlen + 2) << 2;
 429                 } else {
 430                         optlen = ipv6_optlen(hdr);
 431                 }
 432                 if (nexthdr == NEXTHDR_DEST) {
 433                         __u16 i = off + 2;
 434                         while (1) {
 435                                 struct ipv6_tlv_tnl_enc_lim *tel;
 436
 437                                 /* No more room for encapsulation limit */
 438                                 if (i + sizeof (*tel) > off + optlen)
 439                                         break;
 440
 441                                 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i];
 442                                 /* return index of option if found and valid */
 443                                 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
 444                                     tel->length == 1)
 445                                         return i;
 446                                 /* else jump to next option */
 447                                 if (tel->type)
 448                                         i += tel->length + 2;
 449                                 else
 450                                         i++;
 451                         }
 452                 }
 453                 nexthdr = hdr->nexthdr;
 454                 off += optlen;
 455         }
 456         return 0;
 457 }
 458 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
 459
 460 /**
 461  * ip6_tnl_err - tunnel error handler
 462  *
 463  * Description:
 464  *   ip6_tnl_err() should handle errors in the tunnel according
 465  *   to the specifications in RFC 2473.
 466  **/
 467
 468 static int
 469 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
 470             u8 *type, u8 *code, int *msg, __u32 *info, int offset)
 471 {
 472         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data;
 473         struct ip6_tnl *t;
 474         int rel_msg = 0;
 475         u8 rel_type = ICMPV6_DEST_UNREACH;
 476         u8 rel_code = ICMPV6_ADDR_UNREACH;
 477         __u32 rel_info = 0;
 478         __u16 len;
 479         int err = -ENOENT;
 480
 481         /* If the packet doesn't contain the original IPv6 header we are
 482            in trouble since we might need the source address for further
 483            processing of the error. */
 484
 485         rcu_read_lock();
 486         if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr,
 487                                         &ipv6h->saddr)) == NULL)
 488                 goto out;
 489
 490         if (t->parms.proto != ipproto && t->parms.proto != 0)
 491                 goto out;
 492
 493         err = 0;
 494
 495         switch (*type) {
 496                 __u32 teli;
 497                 struct ipv6_tlv_tnl_enc_lim *tel;
 498                 __u32 mtu;
 499         case ICMPV6_DEST_UNREACH:
 500                 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
 501                                      t->parms.name);
 502                 rel_msg = 1;
 503                 break;
 504         case ICMPV6_TIME_EXCEED:
 505                 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
 506                         net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 507                                              t->parms.name);
 508                         rel_msg = 1;
 509                 }
 510                 break;
 511         case ICMPV6_PARAMPROB:
 512                 teli = 0;
 513                 if ((*code) == ICMPV6_HDR_FIELD)
 514                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 515
 516                 if (teli && teli == *info - 2) {
 517                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 518                         if (tel->encap_limit == 0) {
 519                                 net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 520                                                      t->parms.name);
 521                                 rel_msg = 1;
 522                         }
 523                 } else {
 524                         net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 525                                              t->parms.name);
 526                 }
 527                 break;
 528         case ICMPV6_PKT_TOOBIG:
 529                 mtu = *info - offset;
 530                 if (mtu < IPV6_MIN_MTU)
 531                         mtu = IPV6_MIN_MTU;
 532                 t->dev->mtu = mtu;
 533
 534                 if ((len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) {
 535                         rel_type = ICMPV6_PKT_TOOBIG;
 536                         rel_code = 0;
 537                         rel_info = mtu;
 538                         rel_msg = 1;
 539                 }
 540                 break;
 541         }
 542
 543         *type = rel_type;
 544         *code = rel_code;
 545         *info = rel_info;
 546         *msg = rel_msg;
 547
 548 out:
 549         rcu_read_unlock();
 550         return err;
 551 }
 552
 553 static int
 554 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 555            u8 type, u8 code, int offset, __be32 info)
 556 {
 557         int rel_msg = 0;
 558         u8 rel_type = type;
 559         u8 rel_code = code;
 560         __u32 rel_info = ntohl(info);
 561         int err;
 562         struct sk_buff *skb2;
 563         const struct iphdr *eiph;
 564         struct rtable *rt;
 565         struct flowi4 fl4;
 566
 567         err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
 568                           &rel_msg, &rel_info, offset);
 569         if (err < 0)
 570                 return err;
 571
 572         if (rel_msg == 0)
 573                 return 0;
 574
 575         switch (rel_type) {
 576         case ICMPV6_DEST_UNREACH:
 577                 if (rel_code != ICMPV6_ADDR_UNREACH)
 578                         return 0;
 579                 rel_type = ICMP_DEST_UNREACH;
 580                 rel_code = ICMP_HOST_UNREACH;
 581                 break;
 582         case ICMPV6_PKT_TOOBIG:
 583                 if (rel_code != 0)
 584                         return 0;
 585                 rel_type = ICMP_DEST_UNREACH;
 586                 rel_code = ICMP_FRAG_NEEDED;
 587                 break;
 588         case NDISC_REDIRECT:
 589                 rel_type = ICMP_REDIRECT;
 590                 rel_code = ICMP_REDIR_HOST;
 591         default:
 592                 return 0;
 593         }
 594
 595         if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
 596                 return 0;
 597
 598         skb2 = skb_clone(skb, GFP_ATOMIC);
 599         if (!skb2)
 600                 return 0;
 601
 602         skb_dst_drop(skb2);
 603
 604         skb_pull(skb2, offset);
 605         skb_reset_network_header(skb2);
 606         eiph = ip_hdr(skb2);
 607
 608         /* Try to guess incoming interface */
 609         rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 610                                    eiph->saddr, 0,
 611                                    0, 0,
 612                                    IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 613         if (IS_ERR(rt))
 614                 goto out;
 615
 616         skb2->dev = rt->dst.dev;
 617
 618         /* route "incoming" packet */
 619         if (rt->rt_flags & RTCF_LOCAL) {
 620                 ip_rt_put(rt);
 621                 rt = NULL;
 622                 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 623                                            eiph->daddr, eiph->saddr,
 624                                            0, 0,
 625                                            IPPROTO_IPIP,
 626                                            RT_TOS(eiph->tos), 0);
 627                 if (IS_ERR(rt) ||
 628                     rt->dst.dev->type != ARPHRD_TUNNEL) {
 629                         if (!IS_ERR(rt))
 630                                 ip_rt_put(rt);
 631                         goto out;
 632                 }
 633                 skb_dst_set(skb2, &rt->dst);
 634         } else {
 635                 ip_rt_put(rt);
 636                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
 637                                    skb2->dev) ||
 638                     skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
 639                         goto out;
 640         }
 641
 642         /* change mtu on this route */
 643         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
 644                 if (rel_info > dst_mtu(skb_dst(skb2)))
 645                         goto out;
 646
 647                 skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info);
 648         }
 649         if (rel_type == ICMP_REDIRECT)
 650                 skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2);
 651
 652         icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
 653
 654 out:
 655         kfree_skb(skb2);
 656         return 0;
 657 }
 658
 659 static int
 660 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 661            u8 type, u8 code, int offset, __be32 info)
 662 {
 663         int rel_msg = 0;
 664         u8 rel_type = type;
 665         u8 rel_code = code;
 666         __u32 rel_info = ntohl(info);
 667         int err;
 668
 669         err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
 670                           &rel_msg, &rel_info, offset);
 671         if (err < 0)
 672                 return err;
 673
 674         if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
 675                 struct rt6_info *rt;
 676                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 677
 678                 if (!skb2)
 679                         return 0;
 680
 681                 skb_dst_drop(skb2);
 682                 skb_pull(skb2, offset);
 683                 skb_reset_network_header(skb2);
 684
 685                 /* Try to guess incoming interface */
 686                 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
 687                                 NULL, 0, 0);
 688
 689                 if (rt && rt->dst.dev)
 690                         skb2->dev = rt->dst.dev;
 691
 692                 icmpv6_send(skb2, rel_type, rel_code, rel_info);
 693
 694                 ip6_rt_put(rt);
 695
 696                 kfree_skb(skb2);
 697         }
 698
 699         return 0;
 700 }
 701
 702 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 703                                        const struct ipv6hdr *ipv6h,
 704                                        struct sk_buff *skb)
 705 {
 706         __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
 707
 708         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 709                 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
 710
 711         return IP6_ECN_decapsulate(ipv6h, skb);
 712 }
 713
 714 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 715                                        const struct ipv6hdr *ipv6h,
 716                                        struct sk_buff *skb)
 717 {
 718         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 719                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
 720
 721         return IP6_ECN_decapsulate(ipv6h, skb);
 722 }
 723
 724 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
 725                              const struct in6_addr *laddr,
 726                              const struct in6_addr *raddr)
 727 {
 728         struct __ip6_tnl_parm *p = &t->parms;
 729         int ltype = ipv6_addr_type(laddr);
 730         int rtype = ipv6_addr_type(raddr);
 731         __u32 flags = 0;
 732
 733         if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
 734                 flags = IP6_TNL_F_CAP_PER_PACKET;
 735         } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 736                    rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 737                    !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
 738                    (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
 739                 if (ltype&IPV6_ADDR_UNICAST)
 740                         flags |= IP6_TNL_F_CAP_XMIT;
 741                 if (rtype&IPV6_ADDR_UNICAST)
 742                         flags |= IP6_TNL_F_CAP_RCV;
 743         }
 744         return flags;
 745 }
 746 EXPORT_SYMBOL(ip6_tnl_get_cap);
 747
 748 /* called with rcu_read_lock() */
 749 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
 750                                   const struct in6_addr *laddr,
 751                                   const struct in6_addr *raddr)
 752 {
 753         struct __ip6_tnl_parm *p = &t->parms;
 754         int ret = 0;
 755         struct net *net = t->net;
 756
 757         if ((p->flags & IP6_TNL_F_CAP_RCV) ||
 758             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
 759              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
 760                 struct net_device *ldev = NULL;
 761
 762                 if (p->link)
 763                         ldev = dev_get_by_index_rcu(net, p->link);
 764
 765                 if ((ipv6_addr_is_multicast(laddr) ||
 766                      likely(ipv6_chk_addr(net, laddr, ldev, 0))) &&
 767                     likely(!ipv6_chk_addr(net, raddr, NULL, 0)))
 768                         ret = 1;
 769         }
 770         return ret;
 771 }
 772 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
 773
 774 /**
 775  * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally
 776  *   @skb: received socket buffer
 777  *   @protocol: ethernet protocol ID
 778  *   @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN
 779  *
 780  * Return: 0
 781  **/
 782
 783 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
 784                        __u8 ipproto,
 785                        int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 786                                                    const struct ipv6hdr *ipv6h,
 787                                                    struct sk_buff *skb))
 788 {
 789         struct ip6_tnl *t;
 790         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 791         int err;
 792
 793         rcu_read_lock();
 794
 795         if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr,
 796                                         &ipv6h->daddr)) != NULL) {
 797                 struct pcpu_sw_netstats *tstats;
 798
 799                 if (t->parms.proto != ipproto && t->parms.proto != 0) {
 800                         rcu_read_unlock();
 801                         goto discard;
 802                 }
 803
 804                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
 805                         rcu_read_unlock();
 806                         goto discard;
 807                 }
 808
 809                 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
 810                         t->dev->stats.rx_dropped++;
 811                         rcu_read_unlock();
 812                         goto discard;
 813                 }
 814                 skb->mac_header = skb->network_header;
 815                 skb_reset_network_header(skb);
 816                 skb->protocol = htons(protocol);
 817                 memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 818
 819                 __skb_tunnel_rx(skb, t->dev, t->net);
 820
 821                 err = dscp_ecn_decapsulate(t, ipv6h, skb);
 822                 if (unlikely(err)) {
 823                         if (log_ecn_error)
 824                                 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
 825                                                      &ipv6h->saddr,
 826                                                      ipv6_get_dsfield(ipv6h));
 827                         if (err > 1) {
 828                                 ++t->dev->stats.rx_frame_errors;
 829                                 ++t->dev->stats.rx_errors;
 830                                 rcu_read_unlock();
 831                                 goto discard;
 832                         }
 833                 }
 834
 835                 tstats = this_cpu_ptr(t->dev->tstats);
 836                 u64_stats_update_begin(&tstats->syncp);
 837                 tstats->rx_packets++;
 838                 tstats->rx_bytes += skb->len;
 839                 u64_stats_update_end(&tstats->syncp);
 840
 841                 netif_rx(skb);
 842
 843                 rcu_read_unlock();
 844                 return 0;
 845         }
 846         rcu_read_unlock();
 847         return 1;
 848
 849 discard:
 850         kfree_skb(skb);
 851         return 0;
 852 }
 853
 854 static int ip4ip6_rcv(struct sk_buff *skb)
 855 {
 856         return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP,
 857                            ip4ip6_dscp_ecn_decapsulate);
 858 }
 859
 860 static int ip6ip6_rcv(struct sk_buff *skb)
 861 {
 862         return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6,
 863                            ip6ip6_dscp_ecn_decapsulate);
 864 }
 865
 866 struct ipv6_tel_txoption {
 867         struct ipv6_txoptions ops;
 868         __u8 dst_opt[8];
 869 };
 870
 871 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 872 {
 873         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 874
 875         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 876         opt->dst_opt[3] = 1;
 877         opt->dst_opt[4] = encap_limit;
 878         opt->dst_opt[5] = IPV6_TLV_PADN;
 879         opt->dst_opt[6] = 1;
 880
 881         opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 882         opt->ops.opt_nflen = 8;
 883 }
 884
 885 /**
 886  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 887  *   @t: the outgoing tunnel device
 888  *   @hdr: IPv6 header from the incoming packet
 889  *
 890  * Description:
 891  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 892  *   doesn't match source of incoming packet.
 893  *
 894  * Return:
 895  *   1 if conflict,
 896  *   0 else
 897  **/
 898
 899 static inline bool
 900 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
 901 {
 902         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 903 }
 904
 905 int ip6_tnl_xmit_ctl(struct ip6_tnl *t)
 906 {
 907         struct __ip6_tnl_parm *p = &t->parms;
 908         int ret = 0;
 909         struct net *net = t->net;
 910
 911         if (p->flags & IP6_TNL_F_CAP_XMIT) {
 912                 struct net_device *ldev = NULL;
 913
 914                 rcu_read_lock();
 915                 if (p->link)
 916                         ldev = dev_get_by_index_rcu(net, p->link);
 917
 918                 if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0)))
 919                         pr_warn("%s xmit: Local address not yet configured!\n",
 920                                 p->name);
 921                 else if (!ipv6_addr_is_multicast(&p->raddr) &&
 922                          unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0)))
 923                         pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
 924                                 p->name);
 925                 else
 926                         ret = 1;
 927                 rcu_read_unlock();
 928         }
 929         return ret;
 930 }
 931 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
 932
 933 /**
 934  * ip6_tnl_xmit2 - encapsulate packet and send
 935  *   @skb: the outgoing socket buffer
 936  *   @dev: the outgoing tunnel device
 937  *   @dsfield: dscp code for outer header
 938  *   @fl: flow of tunneled packet
 939  *   @encap_limit: encapsulation limit
 940  *   @pmtu: Path MTU is stored if packet is too big
 941  *
 942  * Description:
 943  *   Build new header and do some sanity checks on the packet before sending
 944  *   it.
 945  *
 946  * Return:
 947  *   0 on success
 948  *   -1 fail
 949  *   %-EMSGSIZE message too big. return mtu in this case.
 950  **/
 951
 952 static int ip6_tnl_xmit2(struct sk_buff *skb,
 953                          struct net_device *dev,
 954                          __u8 dsfield,
 955                          struct flowi6 *fl6,
 956                          int encap_limit,
 957                          __u32 *pmtu)
 958 {
 959         struct ip6_tnl *t = netdev_priv(dev);
 960         struct net *net = t->net;
 961         struct net_device_stats *stats = &t->dev->stats;
 962         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 963         struct ipv6_tel_txoption opt;
 964         struct dst_entry *dst = NULL, *ndst = NULL;
 965         struct net_device *tdev;
 966         int mtu;
 967         unsigned int max_headroom = sizeof(struct ipv6hdr);
 968         u8 proto;
 969         int err = -1;
 970
 971         if (!fl6->flowi6_mark)
 972                 dst = ip6_tnl_dst_check(t);
 973         if (!dst) {
 974                 ndst = ip6_route_output(net, NULL, fl6);
 975
 976                 if (ndst->error)
 977                         goto tx_err_link_failure;
 978                 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
 979                 if (IS_ERR(ndst)) {
 980                         err = PTR_ERR(ndst);
 981                         ndst = NULL;
 982                         goto tx_err_link_failure;
 983                 }
 984                 dst = ndst;
 985         }
 986
 987         tdev = dst->dev;
 988
 989         if (tdev == dev) {
 990                 stats->collisions++;
 991                 net_warn_ratelimited("%s: Local routing loop detected!\n",
 992                                      t->parms.name);
 993                 goto tx_err_dst_release;
 994         }
 995         mtu = dst_mtu(dst) - sizeof(*ipv6h);
 996         if (encap_limit >= 0) {
 997                 max_headroom += 8;
 998                 mtu -= 8;
 999         }
1000         if (mtu < IPV6_MIN_MTU)
1001                 mtu = IPV6_MIN_MTU;
1002         if (skb_dst(skb))
1003                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
1004         if (skb->len > mtu) {
1005                 *pmtu = mtu;
1006                 err = -EMSGSIZE;
1007                 goto tx_err_dst_release;
1008         }
1009
1010         skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1011
1012         /*
1013          * Okay, now see if we can stuff it in the buffer as-is.
1014          */
1015         max_headroom += LL_RESERVED_SPACE(tdev);
1016
1017         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1018             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1019                 struct sk_buff *new_skb;
1020
1021                 if (!(new_skb = skb_realloc_headroom(skb, max_headroom)))
1022                         goto tx_err_dst_release;
1023
1024                 if (skb->sk)
1025                         skb_set_owner_w(new_skb, skb->sk);
1026                 consume_skb(skb);
1027                 skb = new_skb;
1028         }
1029         if (fl6->flowi6_mark) {
1030                 skb_dst_set(skb, dst);
1031                 ndst = NULL;
1032         } else {
1033                 skb_dst_set_noref(skb, dst);
1034         }
1035         skb->transport_header = skb->network_header;
1036
1037         proto = fl6->flowi6_proto;
1038         if (encap_limit >= 0) {
1039                 init_tel_txopt(&opt, encap_limit);
1040                 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
1041         }
1042
1043         if (likely(!skb->encapsulation)) {
1044                 skb_reset_inner_headers(skb);
1045                 skb->encapsulation = 1;
1046         }
1047
1048         skb_push(skb, sizeof(struct ipv6hdr));
1049         skb_reset_network_header(skb);
1050         ipv6h = ipv6_hdr(skb);
1051         ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield),
1052                      ip6_make_flowlabel(net, skb, fl6->flowlabel, false));
1053         ipv6h->hop_limit = t->parms.hop_limit;
1054         ipv6h->nexthdr = proto;
1055         ipv6h->saddr = fl6->saddr;
1056         ipv6h->daddr = fl6->daddr;
1057         ip6tunnel_xmit(skb, dev);
1058         if (ndst)
1059                 ip6_tnl_dst_store(t, ndst);
1060         return 0;
1061 tx_err_link_failure:
1062         stats->tx_carrier_errors++;
1063         dst_link_failure(skb);
1064 tx_err_dst_release:
1065         dst_release(ndst);
1066         return err;
1067 }
1068
1069 static inline int
1070 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1071 {
1072         struct ip6_tnl *t = netdev_priv(dev);
1073         const struct iphdr  *iph = ip_hdr(skb);
1074         int encap_limit = -1;
1075         struct flowi6 fl6;
1076         __u8 dsfield;
1077         __u32 mtu;
1078         int err;
1079
1080         if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) ||
1081             !ip6_tnl_xmit_ctl(t))
1082                 return -1;
1083
1084         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1085                 encap_limit = t->parms.encap_limit;
1086
1087         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1088         fl6.flowi6_proto = IPPROTO_IPIP;
1089
1090         dsfield = ipv4_get_dsfield(iph);
1091
1092         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1093                 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
1094                                           & IPV6_TCLASS_MASK;
1095         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1096                 fl6.flowi6_mark = skb->mark;
1097
1098         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1099         if (err != 0) {
1100                 /* XXX: send ICMP error even if DF is not set. */
1101                 if (err == -EMSGSIZE)
1102                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1103                                   htonl(mtu));
1104                 return -1;
1105         }
1106
1107         return 0;
1108 }
1109
1110 static inline int
1111 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1112 {
1113         struct ip6_tnl *t = netdev_priv(dev);
1114         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1115         int encap_limit = -1;
1116         __u16 offset;
1117         struct flowi6 fl6;
1118         __u8 dsfield;
1119         __u32 mtu;
1120         int err;
1121
1122         if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
1123             !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h))
1124                 return -1;
1125
1126         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1127         if (offset > 0) {
1128                 struct ipv6_tlv_tnl_enc_lim *tel;
1129                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
1130                 if (tel->encap_limit == 0) {
1131                         icmpv6_send(skb, ICMPV6_PARAMPROB,
1132                                     ICMPV6_HDR_FIELD, offset + 2);
1133                         return -1;
1134                 }
1135                 encap_limit = tel->encap_limit - 1;
1136         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1137                 encap_limit = t->parms.encap_limit;
1138
1139         memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1140         fl6.flowi6_proto = IPPROTO_IPV6;
1141
1142         dsfield = ipv6_get_dsfield(ipv6h);
1143         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1144                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
1145         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1146                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
1147         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1148                 fl6.flowi6_mark = skb->mark;
1149
1150         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1151         if (err != 0) {
1152                 if (err == -EMSGSIZE)
1153                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1154                 return -1;
1155         }
1156
1157         return 0;
1158 }
1159
1160 static netdev_tx_t
1161 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1162 {
1163         struct ip6_tnl *t = netdev_priv(dev);
1164         struct net_device_stats *stats = &t->dev->stats;
1165         int ret;
1166
1167         switch (skb->protocol) {
1168         case htons(ETH_P_IP):
1169                 ret = ip4ip6_tnl_xmit(skb, dev);
1170                 break;
1171         case htons(ETH_P_IPV6):
1172                 ret = ip6ip6_tnl_xmit(skb, dev);
1173                 break;
1174         default:
1175                 goto tx_err;
1176         }
1177
1178         if (ret < 0)
1179                 goto tx_err;
1180
1181         return NETDEV_TX_OK;
1182
1183 tx_err:
1184         stats->tx_errors++;
1185         stats->tx_dropped++;
1186         kfree_skb(skb);
1187         return NETDEV_TX_OK;
1188 }
1189
1190 static void ip6_tnl_link_config(struct ip6_tnl *t)
1191 {
1192         struct net_device *dev = t->dev;
1193         struct __ip6_tnl_parm *p = &t->parms;
1194         struct flowi6 *fl6 = &t->fl.u.ip6;
1195
1196         memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1197         memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1198
1199         /* Set up flowi template */
1200         fl6->saddr = p->laddr;
1201         fl6->daddr = p->raddr;
1202         fl6->flowi6_oif = p->link;
1203         fl6->flowlabel = 0;
1204
1205         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1206                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1207         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1208                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1209
1210         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1211         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1212
1213         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1214                 dev->flags |= IFF_POINTOPOINT;
1215         else
1216                 dev->flags &= ~IFF_POINTOPOINT;
1217
1218         dev->iflink = p->link;
1219
1220         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1221                 int strict = (ipv6_addr_type(&p->raddr) &
1222                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1223
1224                 struct rt6_info *rt = rt6_lookup(t->net,
1225                                                  &p->raddr, &p->laddr,
1226                                                  p->link, strict);
1227
1228                 if (rt == NULL)
1229                         return;
1230
1231                 if (rt->dst.dev) {
1232                         dev->hard_header_len = rt->dst.dev->hard_header_len +
1233                                 sizeof(struct ipv6hdr);
1234
1235                         dev->mtu = rt->dst.dev->mtu - sizeof(struct ipv6hdr);
1236                         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1237                                 dev->mtu -= 8;
1238
1239                         if (dev->mtu < IPV6_MIN_MTU)
1240                                 dev->mtu = IPV6_MIN_MTU;
1241                 }
1242                 ip6_rt_put(rt);
1243         }
1244 }
1245
1246 /**
1247  * ip6_tnl_change - update the tunnel parameters
1248  *   @t: tunnel to be changed
1249  *   @p: tunnel configuration parameters
1250  *
1251  * Description:
1252  *   ip6_tnl_change() updates the tunnel parameters
1253  **/
1254
1255 static int
1256 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1257 {
1258         t->parms.laddr = p->laddr;
1259         t->parms.raddr = p->raddr;
1260         t->parms.flags = p->flags;
1261         t->parms.hop_limit = p->hop_limit;
1262         t->parms.encap_limit = p->encap_limit;
1263         t->parms.flowinfo = p->flowinfo;
1264         t->parms.link = p->link;
1265         t->parms.proto = p->proto;
1266         ip6_tnl_dst_reset(t);
1267         ip6_tnl_link_config(t);
1268         return 0;
1269 }
1270
1271 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1272 {
1273         struct net *net = t->net;
1274         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1275         int err;
1276
1277         ip6_tnl_unlink(ip6n, t);
1278         synchronize_net();
1279         err = ip6_tnl_change(t, p);
1280         ip6_tnl_link(ip6n, t);
1281         netdev_state_change(t->dev);
1282         return err;
1283 }
1284
1285 static void
1286 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1287 {
1288         p->laddr = u->laddr;
1289         p->raddr = u->raddr;
1290         p->flags = u->flags;
1291         p->hop_limit = u->hop_limit;
1292         p->encap_limit = u->encap_limit;
1293         p->flowinfo = u->flowinfo;
1294         p->link = u->link;
1295         p->proto = u->proto;
1296         memcpy(p->name, u->name, sizeof(u->name));
1297 }
1298
1299 static void
1300 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1301 {
1302         u->laddr = p->laddr;
1303         u->raddr = p->raddr;
1304         u->flags = p->flags;
1305         u->hop_limit = p->hop_limit;
1306         u->encap_limit = p->encap_limit;
1307         u->flowinfo = p->flowinfo;
1308         u->link = p->link;
1309         u->proto = p->proto;
1310         memcpy(u->name, p->name, sizeof(u->name));
1311 }
1312
1313 /**
1314  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1315  *   @dev: virtual device associated with tunnel
1316  *   @ifr: parameters passed from userspace
1317  *   @cmd: command to be performed
1318  *
1319  * Description:
1320  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1321  *   from userspace.
1322  *
1323  *   The possible commands are the following:
1324  *     %SIOCGETTUNNEL: get tunnel parameters for device
1325  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1326  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1327  *     %SIOCDELTUNNEL: delete tunnel
1328  *
1329  *   The fallback device "ip6tnl0", created during module
1330  *   initialization, can be used for creating other tunnel devices.
1331  *
1332  * Return:
1333  *   0 on success,
1334  *   %-EFAULT if unable to copy data to or from userspace,
1335  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1336  *   %-EINVAL if passed tunnel parameters are invalid,
1337  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1338  *   %-ENODEV if attempting to change or delete a nonexisting device
1339  **/
1340
1341 static int
1342 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1343 {
1344         int err = 0;
1345         struct ip6_tnl_parm p;
1346         struct __ip6_tnl_parm p1;
1347         struct ip6_tnl *t = netdev_priv(dev);
1348         struct net *net = t->net;
1349         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1350
1351         switch (cmd) {
1352         case SIOCGETTUNNEL:
1353                 if (dev == ip6n->fb_tnl_dev) {
1354                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1355                                 err = -EFAULT;
1356                                 break;
1357                         }
1358                         ip6_tnl_parm_from_user(&p1, &p);
1359                         t = ip6_tnl_locate(net, &p1, 0);
1360                         if (t == NULL)
1361                                 t = netdev_priv(dev);
1362                 } else {
1363                         memset(&p, 0, sizeof(p));
1364                 }
1365                 ip6_tnl_parm_to_user(&p, &t->parms);
1366                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1367                         err = -EFAULT;
1368                 }
1369                 break;
1370         case SIOCADDTUNNEL:
1371         case SIOCCHGTUNNEL:
1372                 err = -EPERM;
1373                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1374                         break;
1375                 err = -EFAULT;
1376                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1377                         break;
1378                 err = -EINVAL;
1379                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1380                     p.proto != 0)
1381                         break;
1382                 ip6_tnl_parm_from_user(&p1, &p);
1383                 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1384                 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
1385                         if (t != NULL) {
1386                                 if (t->dev != dev) {
1387                                         err = -EEXIST;
1388                                         break;
1389                                 }
1390                         } else
1391                                 t = netdev_priv(dev);
1392
1393                         err = ip6_tnl_update(t, &p1);
1394                 }
1395                 if (t) {
1396                         err = 0;
1397                         ip6_tnl_parm_to_user(&p, &t->parms);
1398                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1399                                 err = -EFAULT;
1400
1401                 } else
1402                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1403                 break;
1404         case SIOCDELTUNNEL:
1405                 err = -EPERM;
1406                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1407                         break;
1408
1409                 if (dev == ip6n->fb_tnl_dev) {
1410                         err = -EFAULT;
1411                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1412                                 break;
1413                         err = -ENOENT;
1414                         ip6_tnl_parm_from_user(&p1, &p);
1415                         t = ip6_tnl_locate(net, &p1, 0);
1416                         if (t == NULL)
1417                                 break;
1418                         err = -EPERM;
1419                         if (t->dev == ip6n->fb_tnl_dev)
1420                                 break;
1421                         dev = t->dev;
1422                 }
1423                 err = 0;
1424                 unregister_netdevice(dev);
1425                 break;
1426         default:
1427                 err = -EINVAL;
1428         }
1429         return err;
1430 }
1431
1432 /**
1433  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1434  *   @dev: virtual device associated with tunnel
1435  *   @new_mtu: the new mtu
1436  *
1437  * Return:
1438  *   0 on success,
1439  *   %-EINVAL if mtu too small
1440  **/
1441
1442 static int
1443 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1444 {
1445         struct ip6_tnl *tnl = netdev_priv(dev);
1446
1447         if (tnl->parms.proto == IPPROTO_IPIP) {
1448                 if (new_mtu < 68)
1449                         return -EINVAL;
1450         } else {
1451                 if (new_mtu < IPV6_MIN_MTU)
1452                         return -EINVAL;
1453         }
1454         if (new_mtu > 0xFFF8 - dev->hard_header_len)
1455                 return -EINVAL;
1456         dev->mtu = new_mtu;
1457         return 0;
1458 }
1459
1460
1461 static const struct net_device_ops ip6_tnl_netdev_ops = {
1462         .ndo_init       = ip6_tnl_dev_init,
1463         .ndo_uninit     = ip6_tnl_dev_uninit,
1464         .ndo_start_xmit = ip6_tnl_xmit,
1465         .ndo_do_ioctl   = ip6_tnl_ioctl,
1466         .ndo_change_mtu = ip6_tnl_change_mtu,
1467         .ndo_get_stats  = ip6_get_stats,
1468 };
1469
1470
1471 /**
1472  * ip6_tnl_dev_setup - setup virtual tunnel device
1473  *   @dev: virtual device associated with tunnel
1474  *
1475  * Description:
1476  *   Initialize function pointers and device parameters
1477  **/
1478
1479 static void ip6_tnl_dev_setup(struct net_device *dev)
1480 {
1481         struct ip6_tnl *t;
1482
1483         dev->netdev_ops = &ip6_tnl_netdev_ops;
1484         dev->destructor = ip6_dev_free;
1485
1486         dev->type = ARPHRD_TUNNEL6;
1487         dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr);
1488         dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr);
1489         t = netdev_priv(dev);
1490         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1491                 dev->mtu -= 8;
1492         dev->flags |= IFF_NOARP;
1493         dev->addr_len = sizeof(struct in6_addr);
1494         netif_keep_dst(dev);
1495         /* This perm addr will be used as interface identifier by IPv6 */
1496         dev->addr_assign_type = NET_ADDR_RANDOM;
1497         eth_random_addr(dev->perm_addr);
1498 }
1499
1500
1501 /**
1502  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1503  *   @dev: virtual device associated with tunnel
1504  **/
1505
1506 static inline int
1507 ip6_tnl_dev_init_gen(struct net_device *dev)
1508 {
1509         struct ip6_tnl *t = netdev_priv(dev);
1510
1511         t->dev = dev;
1512         t->net = dev_net(dev);
1513         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1514         if (!dev->tstats)
1515                 return -ENOMEM;
1516         return 0;
1517 }
1518
1519 /**
1520  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1521  *   @dev: virtual device associated with tunnel
1522  **/
1523
1524 static int ip6_tnl_dev_init(struct net_device *dev)
1525 {
1526         struct ip6_tnl *t = netdev_priv(dev);
1527         int err = ip6_tnl_dev_init_gen(dev);
1528
1529         if (err)
1530                 return err;
1531         ip6_tnl_link_config(t);
1532         return 0;
1533 }
1534
1535 /**
1536  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1537  *   @dev: fallback device
1538  *
1539  * Return: 0
1540  **/
1541
1542 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1543 {
1544         struct ip6_tnl *t = netdev_priv(dev);
1545         struct net *net = dev_net(dev);
1546         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1547
1548         t->parms.proto = IPPROTO_IPV6;
1549         dev_hold(dev);
1550
1551         rcu_assign_pointer(ip6n->tnls_wc[0], t);
1552         return 0;
1553 }
1554
1555 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[])
1556 {
1557         u8 proto;
1558
1559         if (!data || !data[IFLA_IPTUN_PROTO])
1560                 return 0;
1561
1562         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1563         if (proto != IPPROTO_IPV6 &&
1564             proto != IPPROTO_IPIP &&
1565             proto != 0)
1566                 return -EINVAL;
1567
1568         return 0;
1569 }
1570
1571 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1572                                   struct __ip6_tnl_parm *parms)
1573 {
1574         memset(parms, 0, sizeof(*parms));
1575
1576         if (!data)
1577                 return;
1578
1579         if (data[IFLA_IPTUN_LINK])
1580                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1581
1582         if (data[IFLA_IPTUN_LOCAL])
1583                 nla_memcpy(&parms->laddr, data[IFLA_IPTUN_LOCAL],
1584                            sizeof(struct in6_addr));
1585
1586         if (data[IFLA_IPTUN_REMOTE])
1587                 nla_memcpy(&parms->raddr, data[IFLA_IPTUN_REMOTE],
1588                            sizeof(struct in6_addr));
1589
1590         if (data[IFLA_IPTUN_TTL])
1591                 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1592
1593         if (data[IFLA_IPTUN_ENCAP_LIMIT])
1594                 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1595
1596         if (data[IFLA_IPTUN_FLOWINFO])
1597                 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1598
1599         if (data[IFLA_IPTUN_FLAGS])
1600                 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1601
1602         if (data[IFLA_IPTUN_PROTO])
1603                 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1604 }
1605
1606 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
1607                            struct nlattr *tb[], struct nlattr *data[])
1608 {
1609         struct net *net = dev_net(dev);
1610         struct ip6_tnl *nt;
1611
1612         nt = netdev_priv(dev);
1613         ip6_tnl_netlink_parms(data, &nt->parms);
1614
1615         if (ip6_tnl_locate(net, &nt->parms, 0))
1616                 return -EEXIST;
1617
1618         return ip6_tnl_create2(dev);
1619 }
1620
1621 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
1622                               struct nlattr *data[])
1623 {
1624         struct ip6_tnl *t = netdev_priv(dev);
1625         struct __ip6_tnl_parm p;
1626         struct net *net = t->net;
1627         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1628
1629         if (dev == ip6n->fb_tnl_dev)
1630                 return -EINVAL;
1631
1632         ip6_tnl_netlink_parms(data, &p);
1633
1634         t = ip6_tnl_locate(net, &p, 0);
1635
1636         if (t) {
1637                 if (t->dev != dev)
1638                         return -EEXIST;
1639         } else
1640                 t = netdev_priv(dev);
1641
1642         return ip6_tnl_update(t, &p);
1643 }
1644
1645 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
1646 {
1647         struct net *net = dev_net(dev);
1648         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1649
1650         if (dev != ip6n->fb_tnl_dev)
1651                 unregister_netdevice_queue(dev, head);
1652 }
1653
1654 static size_t ip6_tnl_get_size(const struct net_device *dev)
1655 {
1656         return
1657                 /* IFLA_IPTUN_LINK */
1658                 nla_total_size(4) +
1659                 /* IFLA_IPTUN_LOCAL */
1660                 nla_total_size(sizeof(struct in6_addr)) +
1661                 /* IFLA_IPTUN_REMOTE */
1662                 nla_total_size(sizeof(struct in6_addr)) +
1663                 /* IFLA_IPTUN_TTL */
1664                 nla_total_size(1) +
1665                 /* IFLA_IPTUN_ENCAP_LIMIT */
1666                 nla_total_size(1) +
1667                 /* IFLA_IPTUN_FLOWINFO */
1668                 nla_total_size(4) +
1669                 /* IFLA_IPTUN_FLAGS */
1670                 nla_total_size(4) +
1671                 /* IFLA_IPTUN_PROTO */
1672                 nla_total_size(1) +
1673                 0;
1674 }
1675
1676 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1677 {
1678         struct ip6_tnl *tunnel = netdev_priv(dev);
1679         struct __ip6_tnl_parm *parm = &tunnel->parms;
1680
1681         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1682             nla_put(skb, IFLA_IPTUN_LOCAL, sizeof(struct in6_addr),
1683                     &parm->laddr) ||
1684             nla_put(skb, IFLA_IPTUN_REMOTE, sizeof(struct in6_addr),
1685                     &parm->raddr) ||
1686             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
1687             nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
1688             nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
1689             nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
1690             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto))
1691                 goto nla_put_failure;
1692         return 0;
1693
1694 nla_put_failure:
1695         return -EMSGSIZE;
1696 }
1697
1698 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
1699         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
1700         [IFLA_IPTUN_LOCAL]              = { .len = sizeof(struct in6_addr) },
1701         [IFLA_IPTUN_REMOTE]             = { .len = sizeof(struct in6_addr) },
1702         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
1703         [IFLA_IPTUN_ENCAP_LIMIT]        = { .type = NLA_U8 },
1704         [IFLA_IPTUN_FLOWINFO]           = { .type = NLA_U32 },
1705         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U32 },
1706         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
1707 };
1708
1709 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
1710         .kind           = "ip6tnl",
1711         .maxtype        = IFLA_IPTUN_MAX,
1712         .policy         = ip6_tnl_policy,
1713         .priv_size      = sizeof(struct ip6_tnl),
1714         .setup          = ip6_tnl_dev_setup,
1715         .validate       = ip6_tnl_validate,
1716         .newlink        = ip6_tnl_newlink,
1717         .changelink     = ip6_tnl_changelink,
1718         .dellink        = ip6_tnl_dellink,
1719         .get_size       = ip6_tnl_get_size,
1720         .fill_info      = ip6_tnl_fill_info,
1721 };
1722
1723 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
1724         .handler        = ip4ip6_rcv,
1725         .err_handler    = ip4ip6_err,
1726         .priority       =       1,
1727 };
1728
1729 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
1730         .handler        = ip6ip6_rcv,
1731         .err_handler    = ip6ip6_err,
1732         .priority       =       1,
1733 };
1734
1735 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net)
1736 {
1737         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1738         struct net_device *dev, *aux;
1739         int h;
1740         struct ip6_tnl *t;
1741         LIST_HEAD(list);
1742
1743         for_each_netdev_safe(net, dev, aux)
1744                 if (dev->rtnl_link_ops == &ip6_link_ops)
1745                         unregister_netdevice_queue(dev, &list);
1746
1747         for (h = 0; h < HASH_SIZE; h++) {
1748                 t = rtnl_dereference(ip6n->tnls_r_l[h]);
1749                 while (t != NULL) {
1750                         /* If dev is in the same netns, it has already
1751                          * been added to the list by the previous loop.
1752                          */
1753                         if (!net_eq(dev_net(t->dev), net))
1754                                 unregister_netdevice_queue(t->dev, &list);
1755                         t = rtnl_dereference(t->next);
1756                 }
1757         }
1758
1759         unregister_netdevice_many(&list);
1760 }
1761
1762 static int __net_init ip6_tnl_init_net(struct net *net)
1763 {
1764         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1765         struct ip6_tnl *t = NULL;
1766         int err;
1767
1768         ip6n->tnls[0] = ip6n->tnls_wc;
1769         ip6n->tnls[1] = ip6n->tnls_r_l;
1770
1771         err = -ENOMEM;
1772         ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
1773                                         NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
1774
1775         if (!ip6n->fb_tnl_dev)
1776                 goto err_alloc_dev;
1777         dev_net_set(ip6n->fb_tnl_dev, net);
1778         ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
1779         /* FB netdevice is special: we have one, and only one per netns.
1780          * Allowing to move it to another netns is clearly unsafe.
1781          */
1782         ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
1783
1784         err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
1785         if (err < 0)
1786                 goto err_register;
1787
1788         err = register_netdev(ip6n->fb_tnl_dev);
1789         if (err < 0)
1790                 goto err_register;
1791
1792         t = netdev_priv(ip6n->fb_tnl_dev);
1793
1794         strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
1795         return 0;
1796
1797 err_register:
1798         ip6_dev_free(ip6n->fb_tnl_dev);
1799 err_alloc_dev:
1800         return err;
1801 }
1802
1803 static void __net_exit ip6_tnl_exit_net(struct net *net)
1804 {
1805         rtnl_lock();
1806         ip6_tnl_destroy_tunnels(net);
1807         rtnl_unlock();
1808 }
1809
1810 static struct pernet_operations ip6_tnl_net_ops = {
1811         .init = ip6_tnl_init_net,
1812         .exit = ip6_tnl_exit_net,
1813         .id   = &ip6_tnl_net_id,
1814         .size = sizeof(struct ip6_tnl_net),
1815 };
1816
1817 /**
1818  * ip6_tunnel_init - register protocol and reserve needed resources
1819  *
1820  * Return: 0 on success
1821  **/
1822
1823 static int __init ip6_tunnel_init(void)
1824 {
1825         int  err;
1826
1827         err = register_pernet_device(&ip6_tnl_net_ops);
1828         if (err < 0)
1829                 goto out_pernet;
1830
1831         err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
1832         if (err < 0) {
1833                 pr_err("%s: can't register ip4ip6\n", __func__);
1834                 goto out_ip4ip6;
1835         }
1836
1837         err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
1838         if (err < 0) {
1839                 pr_err("%s: can't register ip6ip6\n", __func__);
1840                 goto out_ip6ip6;
1841         }
1842         err = rtnl_link_register(&ip6_link_ops);
1843         if (err < 0)
1844                 goto rtnl_link_failed;
1845
1846         return 0;
1847
1848 rtnl_link_failed:
1849         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
1850 out_ip6ip6:
1851         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
1852 out_ip4ip6:
1853         unregister_pernet_device(&ip6_tnl_net_ops);
1854 out_pernet:
1855         return err;
1856 }
1857
1858 /**
1859  * ip6_tunnel_cleanup - free resources and unregister protocol
1860  **/
1861
1862 static void __exit ip6_tunnel_cleanup(void)
1863 {
1864         rtnl_link_unregister(&ip6_link_ops);
1865         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
1866                 pr_info("%s: can't deregister ip4ip6\n", __func__);
1867
1868         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
1869                 pr_info("%s: can't deregister ip6ip6\n", __func__);
1870
1871         unregister_pernet_device(&ip6_tnl_net_ops);
1872 }
1873
1874 module_init(ip6_tunnel_init);
1875 module_exit(ip6_tunnel_cleanup);