Pileus Git - ~andy/linux/blob - 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_NETDEV("ip6tnl0");
  65
  66 #ifdef IP6_TNL_DEBUG
  67 #define IP6_TNL_TRACE(x...) pr_debug("%s:" x "\n", __func__)
  68 #else
  69 #define IP6_TNL_TRACE(x...) do {;} while(0)
  70 #endif
  71
  72 #define HASH_SIZE_SHIFT  5
  73 #define HASH_SIZE (1 << HASH_SIZE_SHIFT)
  74
  75 static bool log_ecn_error = true;
  76 module_param(log_ecn_error, bool, 0644);
  77 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  78
  79 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
  80 {
  81         u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
  82
  83         return hash_32(hash, HASH_SIZE_SHIFT);
  84 }
  85
  86 static int ip6_tnl_dev_init(struct net_device *dev);
  87 static void ip6_tnl_dev_setup(struct net_device *dev);
  88 static struct rtnl_link_ops ip6_link_ops __read_mostly;
  89
  90 static int ip6_tnl_net_id __read_mostly;
  91 struct ip6_tnl_net {
  92         /* the IPv6 tunnel fallback device */
  93         struct net_device *fb_tnl_dev;
  94         /* lists for storing tunnels in use */
  95         struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE];
  96         struct ip6_tnl __rcu *tnls_wc[1];
  97         struct ip6_tnl __rcu **tnls[2];
  98 };
  99
 100 static struct net_device_stats *ip6_get_stats(struct net_device *dev)
 101 {
 102         struct pcpu_sw_netstats tmp, sum = { 0 };
 103         int i;
 104
 105         for_each_possible_cpu(i) {
 106                 unsigned int start;
 107                 const struct pcpu_sw_netstats *tstats =
 108                                                    per_cpu_ptr(dev->tstats, i);
 109
 110                 do {
 111                         start = u64_stats_fetch_begin_bh(&tstats->syncp);
 112                         tmp.rx_packets = tstats->rx_packets;
 113                         tmp.rx_bytes = tstats->rx_bytes;
 114                         tmp.tx_packets = tstats->tx_packets;
 115                         tmp.tx_bytes =  tstats->tx_bytes;
 116                 } while (u64_stats_fetch_retry_bh(&tstats->syncp, start));
 117
 118                 sum.rx_packets += tmp.rx_packets;
 119                 sum.rx_bytes   += tmp.rx_bytes;
 120                 sum.tx_packets += tmp.tx_packets;
 121                 sum.tx_bytes   += tmp.tx_bytes;
 122         }
 123         dev->stats.rx_packets = sum.rx_packets;
 124         dev->stats.rx_bytes   = sum.rx_bytes;
 125         dev->stats.tx_packets = sum.tx_packets;
 126         dev->stats.tx_bytes   = sum.tx_bytes;
 127         return &dev->stats;
 128 }
 129
 130 /*
 131  * Locking : hash tables are protected by RCU and RTNL
 132  */
 133
 134 struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t)
 135 {
 136         struct dst_entry *dst = t->dst_cache;
 137
 138         if (dst && dst->obsolete &&
 139             dst->ops->check(dst, t->dst_cookie) == NULL) {
 140                 t->dst_cache = NULL;
 141                 dst_release(dst);
 142                 return NULL;
 143         }
 144
 145         return dst;
 146 }
 147 EXPORT_SYMBOL_GPL(ip6_tnl_dst_check);
 148
 149 void ip6_tnl_dst_reset(struct ip6_tnl *t)
 150 {
 151         dst_release(t->dst_cache);
 152         t->dst_cache = NULL;
 153 }
 154 EXPORT_SYMBOL_GPL(ip6_tnl_dst_reset);
 155
 156 void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst)
 157 {
 158         struct rt6_info *rt = (struct rt6_info *) dst;
 159         t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
 160         dst_release(t->dst_cache);
 161         t->dst_cache = dst;
 162 }
 163 EXPORT_SYMBOL_GPL(ip6_tnl_dst_store);
 164
 165 /**
 166  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
 167  *   @remote: the address of the tunnel exit-point
 168  *   @local: the address of the tunnel entry-point
 169  *
 170  * Return:
 171  *   tunnel matching given end-points if found,
 172  *   else fallback tunnel if its device is up,
 173  *   else %NULL
 174  **/
 175
 176 #define for_each_ip6_tunnel_rcu(start) \
 177         for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
 178
 179 static struct ip6_tnl *
 180 ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
 181 {
 182         unsigned int hash = HASH(remote, local);
 183         struct ip6_tnl *t;
 184         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 185
 186         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 187                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 188                     ipv6_addr_equal(remote, &t->parms.raddr) &&
 189                     (t->dev->flags & IFF_UP))
 190                         return t;
 191         }
 192         t = rcu_dereference(ip6n->tnls_wc[0]);
 193         if (t && (t->dev->flags & IFF_UP))
 194                 return t;
 195
 196         return NULL;
 197 }
 198
 199 /**
 200  * ip6_tnl_bucket - get head of list matching given tunnel parameters
 201  *   @p: parameters containing tunnel end-points
 202  *
 203  * Description:
 204  *   ip6_tnl_bucket() returns the head of the list matching the
 205  *   &struct in6_addr entries laddr and raddr in @p.
 206  *
 207  * Return: head of IPv6 tunnel list
 208  **/
 209
 210 static struct ip6_tnl __rcu **
 211 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
 212 {
 213         const struct in6_addr *remote = &p->raddr;
 214         const struct in6_addr *local = &p->laddr;
 215         unsigned int h = 0;
 216         int prio = 0;
 217
 218         if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
 219                 prio = 1;
 220                 h = HASH(remote, local);
 221         }
 222         return &ip6n->tnls[prio][h];
 223 }
 224
 225 /**
 226  * ip6_tnl_link - add tunnel to hash table
 227  *   @t: tunnel to be added
 228  **/
 229
 230 static void
 231 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 232 {
 233         struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
 234
 235         rcu_assign_pointer(t->next , rtnl_dereference(*tp));
 236         rcu_assign_pointer(*tp, t);
 237 }
 238
 239 /**
 240  * ip6_tnl_unlink - remove tunnel from hash table
 241  *   @t: tunnel to be removed
 242  **/
 243
 244 static void
 245 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 246 {
 247         struct ip6_tnl __rcu **tp;
 248         struct ip6_tnl *iter;
 249
 250         for (tp = ip6_tnl_bucket(ip6n, &t->parms);
 251              (iter = rtnl_dereference(*tp)) != NULL;
 252              tp = &iter->next) {
 253                 if (t == iter) {
 254                         rcu_assign_pointer(*tp, t->next);
 255                         break;
 256                 }
 257         }
 258 }
 259
 260 static void ip6_dev_free(struct net_device *dev)
 261 {
 262         free_percpu(dev->tstats);
 263         free_netdev(dev);
 264 }
 265
 266 static int ip6_tnl_create2(struct net_device *dev)
 267 {
 268         struct ip6_tnl *t = netdev_priv(dev);
 269         struct net *net = dev_net(dev);
 270         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 271         int err;
 272
 273         t = netdev_priv(dev);
 274         err = ip6_tnl_dev_init(dev);
 275         if (err < 0)
 276                 goto out;
 277
 278         err = register_netdevice(dev);
 279         if (err < 0)
 280                 goto out;
 281
 282         strcpy(t->parms.name, dev->name);
 283         dev->rtnl_link_ops = &ip6_link_ops;
 284
 285         dev_hold(dev);
 286         ip6_tnl_link(ip6n, t);
 287         return 0;
 288
 289 out:
 290         return err;
 291 }
 292
 293 /**
 294  * ip6_tnl_create - create a new tunnel
 295  *   @p: tunnel parameters
 296  *   @pt: pointer to new tunnel
 297  *
 298  * Description:
 299  *   Create tunnel matching given parameters.
 300  *
 301  * Return:
 302  *   created tunnel or NULL
 303  **/
 304
 305 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
 306 {
 307         struct net_device *dev;
 308         struct ip6_tnl *t;
 309         char name[IFNAMSIZ];
 310         int err;
 311
 312         if (p->name[0])
 313                 strlcpy(name, p->name, IFNAMSIZ);
 314         else
 315                 sprintf(name, "ip6tnl%%d");
 316
 317         dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup);
 318         if (dev == NULL)
 319                 goto failed;
 320
 321         dev_net_set(dev, net);
 322
 323         t = netdev_priv(dev);
 324         t->parms = *p;
 325         t->net = dev_net(dev);
 326         err = ip6_tnl_create2(dev);
 327         if (err < 0)
 328                 goto failed_free;
 329
 330         return t;
 331
 332 failed_free:
 333         ip6_dev_free(dev);
 334 failed:
 335         return NULL;
 336 }
 337
 338 /**
 339  * ip6_tnl_locate - find or create tunnel matching given parameters
 340  *   @p: tunnel parameters
 341  *   @create: != 0 if allowed to create new tunnel if no match found
 342  *
 343  * Description:
 344  *   ip6_tnl_locate() first tries to locate an existing tunnel
 345  *   based on @parms. If this is unsuccessful, but @create is set a new
 346  *   tunnel device is created and registered for use.
 347  *
 348  * Return:
 349  *   matching tunnel or NULL
 350  **/
 351
 352 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
 353                 struct __ip6_tnl_parm *p, int create)
 354 {
 355         const struct in6_addr *remote = &p->raddr;
 356         const struct in6_addr *local = &p->laddr;
 357         struct ip6_tnl __rcu **tp;
 358         struct ip6_tnl *t;
 359         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 360
 361         for (tp = ip6_tnl_bucket(ip6n, p);
 362              (t = rtnl_dereference(*tp)) != NULL;
 363              tp = &t->next) {
 364                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 365                     ipv6_addr_equal(remote, &t->parms.raddr))
 366                         return t;
 367         }
 368         if (!create)
 369                 return NULL;
 370         return ip6_tnl_create(net, p);
 371 }
 372
 373 /**
 374  * ip6_tnl_dev_uninit - tunnel device uninitializer
 375  *   @dev: the device to be destroyed
 376  *
 377  * Description:
 378  *   ip6_tnl_dev_uninit() removes tunnel from its list
 379  **/
 380
 381 static void
 382 ip6_tnl_dev_uninit(struct net_device *dev)
 383 {
 384         struct ip6_tnl *t = netdev_priv(dev);
 385         struct net *net = t->net;
 386         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 387
 388         if (dev == ip6n->fb_tnl_dev)
 389                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
 390         else
 391                 ip6_tnl_unlink(ip6n, t);
 392         ip6_tnl_dst_reset(t);
 393         dev_put(dev);
 394 }
 395
 396 /**
 397  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
 398  *   @skb: received socket buffer
 399  *
 400  * Return:
 401  *   0 if none was found,
 402  *   else index to encapsulation limit
 403  **/
 404
 405 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
 406 {
 407         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) raw;
 408         __u8 nexthdr = ipv6h->nexthdr;
 409         __u16 off = sizeof (*ipv6h);
 410
 411         while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
 412                 __u16 optlen = 0;
 413                 struct ipv6_opt_hdr *hdr;
 414                 if (raw + off + sizeof (*hdr) > skb->data &&
 415                     !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr)))
 416                         break;
 417
 418                 hdr = (struct ipv6_opt_hdr *) (raw + off);
 419                 if (nexthdr == NEXTHDR_FRAGMENT) {
 420                         struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
 421                         if (frag_hdr->frag_off)
 422                                 break;
 423                         optlen = 8;
 424                 } else if (nexthdr == NEXTHDR_AUTH) {
 425                         optlen = (hdr->hdrlen + 2) << 2;
 426                 } else {
 427                         optlen = ipv6_optlen(hdr);
 428                 }
 429                 if (nexthdr == NEXTHDR_DEST) {
 430                         __u16 i = off + 2;
 431                         while (1) {
 432                                 struct ipv6_tlv_tnl_enc_lim *tel;
 433
 434                                 /* No more room for encapsulation limit */
 435                                 if (i + sizeof (*tel) > off + optlen)
 436                                         break;
 437
 438                                 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i];
 439                                 /* return index of option if found and valid */
 440                                 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
 441                                     tel->length == 1)
 442                                         return i;
 443                                 /* else jump to next option */
 444                                 if (tel->type)
 445                                         i += tel->length + 2;
 446                                 else
 447                                         i++;
 448                         }
 449                 }
 450                 nexthdr = hdr->nexthdr;
 451                 off += optlen;
 452         }
 453         return 0;
 454 }
 455 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
 456
 457 /**
 458  * ip6_tnl_err - tunnel error handler
 459  *
 460  * Description:
 461  *   ip6_tnl_err() should handle errors in the tunnel according
 462  *   to the specifications in RFC 2473.
 463  **/
 464
 465 static int
 466 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
 467             u8 *type, u8 *code, int *msg, __u32 *info, int offset)
 468 {
 469         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data;
 470         struct ip6_tnl *t;
 471         int rel_msg = 0;
 472         u8 rel_type = ICMPV6_DEST_UNREACH;
 473         u8 rel_code = ICMPV6_ADDR_UNREACH;
 474         __u32 rel_info = 0;
 475         __u16 len;
 476         int err = -ENOENT;
 477
 478         /* If the packet doesn't contain the original IPv6 header we are
 479            in trouble since we might need the source address for further
 480            processing of the error. */
 481
 482         rcu_read_lock();
 483         if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr,
 484                                         &ipv6h->saddr)) == NULL)
 485                 goto out;
 486
 487         if (t->parms.proto != ipproto && t->parms.proto != 0)
 488                 goto out;
 489
 490         err = 0;
 491
 492         switch (*type) {
 493                 __u32 teli;
 494                 struct ipv6_tlv_tnl_enc_lim *tel;
 495                 __u32 mtu;
 496         case ICMPV6_DEST_UNREACH:
 497                 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n",
 498                                      t->parms.name);
 499                 rel_msg = 1;
 500                 break;
 501         case ICMPV6_TIME_EXCEED:
 502                 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
 503                         net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 504                                              t->parms.name);
 505                         rel_msg = 1;
 506                 }
 507                 break;
 508         case ICMPV6_PARAMPROB:
 509                 teli = 0;
 510                 if ((*code) == ICMPV6_HDR_FIELD)
 511                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 512
 513                 if (teli && teli == *info - 2) {
 514                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 515                         if (tel->encap_limit == 0) {
 516                                 net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 517                                                      t->parms.name);
 518                                 rel_msg = 1;
 519                         }
 520                 } else {
 521                         net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 522                                              t->parms.name);
 523                 }
 524                 break;
 525         case ICMPV6_PKT_TOOBIG:
 526                 mtu = *info - offset;
 527                 if (mtu < IPV6_MIN_MTU)
 528                         mtu = IPV6_MIN_MTU;
 529                 t->dev->mtu = mtu;
 530
 531                 if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) {
 532                         rel_type = ICMPV6_PKT_TOOBIG;
 533                         rel_code = 0;
 534                         rel_info = mtu;
 535                         rel_msg = 1;
 536                 }
 537                 break;
 538         }
 539
 540         *type = rel_type;
 541         *code = rel_code;
 542         *info = rel_info;
 543         *msg = rel_msg;
 544
 545 out:
 546         rcu_read_unlock();
 547         return err;
 548 }
 549
 550 static int
 551 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 552            u8 type, u8 code, int offset, __be32 info)
 553 {
 554         int rel_msg = 0;
 555         u8 rel_type = type;
 556         u8 rel_code = code;
 557         __u32 rel_info = ntohl(info);
 558         int err;
 559         struct sk_buff *skb2;
 560         const struct iphdr *eiph;
 561         struct rtable *rt;
 562         struct flowi4 fl4;
 563
 564         err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
 565                           &rel_msg, &rel_info, offset);
 566         if (err < 0)
 567                 return err;
 568
 569         if (rel_msg == 0)
 570                 return 0;
 571
 572         switch (rel_type) {
 573         case ICMPV6_DEST_UNREACH:
 574                 if (rel_code != ICMPV6_ADDR_UNREACH)
 575                         return 0;
 576                 rel_type = ICMP_DEST_UNREACH;
 577                 rel_code = ICMP_HOST_UNREACH;
 578                 break;
 579         case ICMPV6_PKT_TOOBIG:
 580                 if (rel_code != 0)
 581                         return 0;
 582                 rel_type = ICMP_DEST_UNREACH;
 583                 rel_code = ICMP_FRAG_NEEDED;
 584                 break;
 585         case NDISC_REDIRECT:
 586                 rel_type = ICMP_REDIRECT;
 587                 rel_code = ICMP_REDIR_HOST;
 588         default:
 589                 return 0;
 590         }
 591
 592         if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
 593                 return 0;
 594
 595         skb2 = skb_clone(skb, GFP_ATOMIC);
 596         if (!skb2)
 597                 return 0;
 598
 599         skb_dst_drop(skb2);
 600
 601         skb_pull(skb2, offset);
 602         skb_reset_network_header(skb2);
 603         eiph = ip_hdr(skb2);
 604
 605         /* Try to guess incoming interface */
 606         rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 607                                    eiph->saddr, 0,
 608                                    0, 0,
 609                                    IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 610         if (IS_ERR(rt))
 611                 goto out;
 612
 613         skb2->dev = rt->dst.dev;
 614
 615         /* route "incoming" packet */
 616         if (rt->rt_flags & RTCF_LOCAL) {
 617                 ip_rt_put(rt);
 618                 rt = NULL;
 619                 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 620                                            eiph->daddr, eiph->saddr,
 621                                            0, 0,
 622                                            IPPROTO_IPIP,
 623                                            RT_TOS(eiph->tos), 0);
 624                 if (IS_ERR(rt) ||
 625                     rt->dst.dev->type != ARPHRD_TUNNEL) {
 626                         if (!IS_ERR(rt))
 627                                 ip_rt_put(rt);
 628                         goto out;
 629                 }
 630                 skb_dst_set(skb2, &rt->dst);
 631         } else {
 632                 ip_rt_put(rt);
 633                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
 634                                    skb2->dev) ||
 635                     skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
 636                         goto out;
 637         }
 638
 639         /* change mtu on this route */
 640         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
 641                 if (rel_info > dst_mtu(skb_dst(skb2)))
 642                         goto out;
 643
 644                 skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info);
 645         }
 646         if (rel_type == ICMP_REDIRECT)
 647                 skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2);
 648
 649         icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
 650
 651 out:
 652         kfree_skb(skb2);
 653         return 0;
 654 }
 655
 656 static int
 657 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 658            u8 type, u8 code, int offset, __be32 info)
 659 {
 660         int rel_msg = 0;
 661         u8 rel_type = type;
 662         u8 rel_code = code;
 663         __u32 rel_info = ntohl(info);
 664         int err;
 665
 666         err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
 667                           &rel_msg, &rel_info, offset);
 668         if (err < 0)
 669                 return err;
 670
 671         if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
 672                 struct rt6_info *rt;
 673                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 674
 675                 if (!skb2)
 676                         return 0;
 677
 678                 skb_dst_drop(skb2);
 679                 skb_pull(skb2, offset);
 680                 skb_reset_network_header(skb2);
 681
 682                 /* Try to guess incoming interface */
 683                 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
 684                                 NULL, 0, 0);
 685
 686                 if (rt && rt->dst.dev)
 687                         skb2->dev = rt->dst.dev;
 688
 689                 icmpv6_send(skb2, rel_type, rel_code, rel_info);
 690
 691                 ip6_rt_put(rt);
 692
 693                 kfree_skb(skb2);
 694         }
 695
 696         return 0;
 697 }
 698
 699 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 700                                        const struct ipv6hdr *ipv6h,
 701                                        struct sk_buff *skb)
 702 {
 703         __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
 704
 705         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 706                 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
 707
 708         return IP6_ECN_decapsulate(ipv6h, skb);
 709 }
 710
 711 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 712                                        const struct ipv6hdr *ipv6h,
 713                                        struct sk_buff *skb)
 714 {
 715         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 716                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
 717
 718         return IP6_ECN_decapsulate(ipv6h, skb);
 719 }
 720
 721 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
 722                              const struct in6_addr *laddr,
 723                              const struct in6_addr *raddr)
 724 {
 725         struct __ip6_tnl_parm *p = &t->parms;
 726         int ltype = ipv6_addr_type(laddr);
 727         int rtype = ipv6_addr_type(raddr);
 728         __u32 flags = 0;
 729
 730         if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
 731                 flags = IP6_TNL_F_CAP_PER_PACKET;
 732         } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 733                    rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 734                    !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
 735                    (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
 736                 if (ltype&IPV6_ADDR_UNICAST)
 737                         flags |= IP6_TNL_F_CAP_XMIT;
 738                 if (rtype&IPV6_ADDR_UNICAST)
 739                         flags |= IP6_TNL_F_CAP_RCV;
 740         }
 741         return flags;
 742 }
 743 EXPORT_SYMBOL(ip6_tnl_get_cap);
 744
 745 /* called with rcu_read_lock() */
 746 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
 747                                   const struct in6_addr *laddr,
 748                                   const struct in6_addr *raddr)
 749 {
 750         struct __ip6_tnl_parm *p = &t->parms;
 751         int ret = 0;
 752         struct net *net = t->net;
 753
 754         if ((p->flags & IP6_TNL_F_CAP_RCV) ||
 755             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
 756              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
 757                 struct net_device *ldev = NULL;
 758
 759                 if (p->link)
 760                         ldev = dev_get_by_index_rcu(net, p->link);
 761
 762                 if ((ipv6_addr_is_multicast(laddr) ||
 763                      likely(ipv6_chk_addr(net, laddr, ldev, 0))) &&
 764                     likely(!ipv6_chk_addr(net, raddr, NULL, 0)))
 765                         ret = 1;
 766         }
 767         return ret;
 768 }
 769 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
 770
 771 /**
 772  * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally
 773  *   @skb: received socket buffer
 774  *   @protocol: ethernet protocol ID
 775  *   @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN
 776  *
 777  * Return: 0
 778  **/
 779
 780 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
 781                        __u8 ipproto,
 782                        int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 783                                                    const struct ipv6hdr *ipv6h,
 784                                                    struct sk_buff *skb))
 785 {
 786         struct ip6_tnl *t;
 787         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 788         int err;
 789
 790         rcu_read_lock();
 791
 792         if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr,
 793                                         &ipv6h->daddr)) != NULL) {
 794                 struct pcpu_sw_netstats *tstats;
 795
 796                 if (t->parms.proto != ipproto && t->parms.proto != 0) {
 797                         rcu_read_unlock();
 798                         goto discard;
 799                 }
 800
 801                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
 802                         rcu_read_unlock();
 803                         goto discard;
 804                 }
 805
 806                 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) {
 807                         t->dev->stats.rx_dropped++;
 808                         rcu_read_unlock();
 809                         goto discard;
 810                 }
 811                 skb->mac_header = skb->network_header;
 812                 skb_reset_network_header(skb);
 813                 skb->protocol = htons(protocol);
 814                 memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 815
 816                 __skb_tunnel_rx(skb, t->dev, t->net);
 817
 818                 err = dscp_ecn_decapsulate(t, ipv6h, skb);
 819                 if (unlikely(err)) {
 820                         if (log_ecn_error)
 821                                 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
 822                                                      &ipv6h->saddr,
 823                                                      ipv6_get_dsfield(ipv6h));
 824                         if (err > 1) {
 825                                 ++t->dev->stats.rx_frame_errors;
 826                                 ++t->dev->stats.rx_errors;
 827                                 rcu_read_unlock();
 828                                 goto discard;
 829                         }
 830                 }
 831
 832                 tstats = this_cpu_ptr(t->dev->tstats);
 833                 u64_stats_update_begin(&tstats->syncp);
 834                 tstats->rx_packets++;
 835                 tstats->rx_bytes += skb->len;
 836                 u64_stats_update_end(&tstats->syncp);
 837
 838                 netif_rx(skb);
 839
 840                 rcu_read_unlock();
 841                 return 0;
 842         }
 843         rcu_read_unlock();
 844         return 1;
 845
 846 discard:
 847         kfree_skb(skb);
 848         return 0;
 849 }
 850
 851 static int ip4ip6_rcv(struct sk_buff *skb)
 852 {
 853         return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP,
 854                            ip4ip6_dscp_ecn_decapsulate);
 855 }
 856
 857 static int ip6ip6_rcv(struct sk_buff *skb)
 858 {
 859         return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6,
 860                            ip6ip6_dscp_ecn_decapsulate);
 861 }
 862
 863 struct ipv6_tel_txoption {
 864         struct ipv6_txoptions ops;
 865         __u8 dst_opt[8];
 866 };
 867
 868 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 869 {
 870         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 871
 872         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 873         opt->dst_opt[3] = 1;
 874         opt->dst_opt[4] = encap_limit;
 875         opt->dst_opt[5] = IPV6_TLV_PADN;
 876         opt->dst_opt[6] = 1;
 877
 878         opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 879         opt->ops.opt_nflen = 8;
 880 }
 881
 882 /**
 883  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 884  *   @t: the outgoing tunnel device
 885  *   @hdr: IPv6 header from the incoming packet
 886  *
 887  * Description:
 888  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 889  *   doesn't match source of incoming packet.
 890  *
 891  * Return:
 892  *   1 if conflict,
 893  *   0 else
 894  **/
 895
 896 static inline bool
 897 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
 898 {
 899         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 900 }
 901
 902 int ip6_tnl_xmit_ctl(struct ip6_tnl *t)
 903 {
 904         struct __ip6_tnl_parm *p = &t->parms;
 905         int ret = 0;
 906         struct net *net = t->net;
 907
 908         if (p->flags & IP6_TNL_F_CAP_XMIT) {
 909                 struct net_device *ldev = NULL;
 910
 911                 rcu_read_lock();
 912                 if (p->link)
 913                         ldev = dev_get_by_index_rcu(net, p->link);
 914
 915                 if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0)))
 916                         pr_warn("%s xmit: Local address not yet configured!\n",
 917                                 p->name);
 918                 else if (!ipv6_addr_is_multicast(&p->raddr) &&
 919                          unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0)))
 920                         pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
 921                                 p->name);
 922                 else
 923                         ret = 1;
 924                 rcu_read_unlock();
 925         }
 926         return ret;
 927 }
 928 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
 929
 930 /**
 931  * ip6_tnl_xmit2 - encapsulate packet and send
 932  *   @skb: the outgoing socket buffer
 933  *   @dev: the outgoing tunnel device
 934  *   @dsfield: dscp code for outer header
 935  *   @fl: flow of tunneled packet
 936  *   @encap_limit: encapsulation limit
 937  *   @pmtu: Path MTU is stored if packet is too big
 938  *
 939  * Description:
 940  *   Build new header and do some sanity checks on the packet before sending
 941  *   it.
 942  *
 943  * Return:
 944  *   0 on success
 945  *   -1 fail
 946  *   %-EMSGSIZE message too big. return mtu in this case.
 947  **/
 948
 949 static int ip6_tnl_xmit2(struct sk_buff *skb,
 950                          struct net_device *dev,
 951                          __u8 dsfield,
 952                          struct flowi6 *fl6,
 953                          int encap_limit,
 954                          __u32 *pmtu)
 955 {
 956         struct ip6_tnl *t = netdev_priv(dev);
 957         struct net *net = t->net;
 958         struct net_device_stats *stats = &t->dev->stats;
 959         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 960         struct ipv6_tel_txoption opt;
 961         struct dst_entry *dst = NULL, *ndst = NULL;
 962         struct net_device *tdev;
 963         int mtu;
 964         unsigned int max_headroom = sizeof(struct ipv6hdr);
 965         u8 proto;
 966         int err = -1;
 967
 968         if (!fl6->flowi6_mark)
 969                 dst = ip6_tnl_dst_check(t);
 970         if (!dst) {
 971                 ndst = ip6_route_output(net, NULL, fl6);
 972
 973                 if (ndst->error)
 974                         goto tx_err_link_failure;
 975                 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0);
 976                 if (IS_ERR(ndst)) {
 977                         err = PTR_ERR(ndst);
 978                         ndst = NULL;
 979                         goto tx_err_link_failure;
 980                 }
 981                 dst = ndst;
 982         }
 983
 984         tdev = dst->dev;
 985
 986         if (tdev == dev) {
 987                 stats->collisions++;
 988                 net_warn_ratelimited("%s: Local routing loop detected!\n",
 989                                      t->parms.name);
 990                 goto tx_err_dst_release;
 991         }
 992         mtu = dst_mtu(dst) - sizeof (*ipv6h);
 993         if (encap_limit >= 0) {
 994                 max_headroom += 8;
 995                 mtu -= 8;
 996         }
 997         if (mtu < IPV6_MIN_MTU)
 998                 mtu = IPV6_MIN_MTU;
 999         if (skb_dst(skb))
1000                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
1001         if (skb->len > mtu) {
1002                 *pmtu = mtu;
1003                 err = -EMSGSIZE;
1004                 goto tx_err_dst_release;
1005         }
1006
1007         skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1008
1009         /*
1010          * Okay, now see if we can stuff it in the buffer as-is.
1011          */
1012         max_headroom += LL_RESERVED_SPACE(tdev);
1013
1014         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1015             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1016                 struct sk_buff *new_skb;
1017
1018                 if (!(new_skb = skb_realloc_headroom(skb, max_headroom)))
1019                         goto tx_err_dst_release;
1020
1021                 if (skb->sk)
1022                         skb_set_owner_w(new_skb, skb->sk);
1023                 consume_skb(skb);
1024                 skb = new_skb;
1025         }
1026         if (fl6->flowi6_mark) {
1027                 skb_dst_set(skb, dst);
1028                 ndst = NULL;
1029         } else {
1030                 skb_dst_set_noref(skb, dst);
1031         }
1032         skb->transport_header = skb->network_header;
1033
1034         proto = fl6->flowi6_proto;
1035         if (encap_limit >= 0) {
1036                 init_tel_txopt(&opt, encap_limit);
1037                 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
1038         }
1039
1040         if (likely(!skb->encapsulation)) {
1041                 skb_reset_inner_headers(skb);
1042                 skb->encapsulation = 1;
1043         }
1044
1045         skb_push(skb, sizeof(struct ipv6hdr));
1046         skb_reset_network_header(skb);
1047         ipv6h = ipv6_hdr(skb);
1048         ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), fl6->flowlabel);
1049         ipv6h->hop_limit = t->parms.hop_limit;
1050         ipv6h->nexthdr = proto;
1051         ipv6h->saddr = fl6->saddr;
1052         ipv6h->daddr = fl6->daddr;
1053         ip6tunnel_xmit(skb, dev);
1054         if (ndst)
1055                 ip6_tnl_dst_store(t, ndst);
1056         return 0;
1057 tx_err_link_failure:
1058         stats->tx_carrier_errors++;
1059         dst_link_failure(skb);
1060 tx_err_dst_release:
1061         dst_release(ndst);
1062         return err;
1063 }
1064
1065 static inline int
1066 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1067 {
1068         struct ip6_tnl *t = netdev_priv(dev);
1069         const struct iphdr  *iph = ip_hdr(skb);
1070         int encap_limit = -1;
1071         struct flowi6 fl6;
1072         __u8 dsfield;
1073         __u32 mtu;
1074         int err;
1075
1076         if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) ||
1077             !ip6_tnl_xmit_ctl(t))
1078                 return -1;
1079
1080         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1081                 encap_limit = t->parms.encap_limit;
1082
1083         memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6));
1084         fl6.flowi6_proto = IPPROTO_IPIP;
1085
1086         dsfield = ipv4_get_dsfield(iph);
1087
1088         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1089                 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
1090                                           & IPV6_TCLASS_MASK;
1091         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1092                 fl6.flowi6_mark = skb->mark;
1093
1094         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1095         if (err != 0) {
1096                 /* XXX: send ICMP error even if DF is not set. */
1097                 if (err == -EMSGSIZE)
1098                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1099                                   htonl(mtu));
1100                 return -1;
1101         }
1102
1103         return 0;
1104 }
1105
1106 static inline int
1107 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1108 {
1109         struct ip6_tnl *t = netdev_priv(dev);
1110         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1111         int encap_limit = -1;
1112         __u16 offset;
1113         struct flowi6 fl6;
1114         __u8 dsfield;
1115         __u32 mtu;
1116         int err;
1117
1118         if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
1119             !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h))
1120                 return -1;
1121
1122         offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1123         if (offset > 0) {
1124                 struct ipv6_tlv_tnl_enc_lim *tel;
1125                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
1126                 if (tel->encap_limit == 0) {
1127                         icmpv6_send(skb, ICMPV6_PARAMPROB,
1128                                     ICMPV6_HDR_FIELD, offset + 2);
1129                         return -1;
1130                 }
1131                 encap_limit = tel->encap_limit - 1;
1132         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1133                 encap_limit = t->parms.encap_limit;
1134
1135         memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6));
1136         fl6.flowi6_proto = IPPROTO_IPV6;
1137
1138         dsfield = ipv6_get_dsfield(ipv6h);
1139         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1140                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
1141         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1142                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
1143         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1144                 fl6.flowi6_mark = skb->mark;
1145
1146         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
1147         if (err != 0) {
1148                 if (err == -EMSGSIZE)
1149                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1150                 return -1;
1151         }
1152
1153         return 0;
1154 }
1155
1156 static netdev_tx_t
1157 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1158 {
1159         struct ip6_tnl *t = netdev_priv(dev);
1160         struct net_device_stats *stats = &t->dev->stats;
1161         int ret;
1162
1163         switch (skb->protocol) {
1164         case htons(ETH_P_IP):
1165                 ret = ip4ip6_tnl_xmit(skb, dev);
1166                 break;
1167         case htons(ETH_P_IPV6):
1168                 ret = ip6ip6_tnl_xmit(skb, dev);
1169                 break;
1170         default:
1171                 goto tx_err;
1172         }
1173
1174         if (ret < 0)
1175                 goto tx_err;
1176
1177         return NETDEV_TX_OK;
1178
1179 tx_err:
1180         stats->tx_errors++;
1181         stats->tx_dropped++;
1182         kfree_skb(skb);
1183         return NETDEV_TX_OK;
1184 }
1185
1186 static void ip6_tnl_link_config(struct ip6_tnl *t)
1187 {
1188         struct net_device *dev = t->dev;
1189         struct __ip6_tnl_parm *p = &t->parms;
1190         struct flowi6 *fl6 = &t->fl.u.ip6;
1191
1192         memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1193         memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1194
1195         /* Set up flowi template */
1196         fl6->saddr = p->laddr;
1197         fl6->daddr = p->raddr;
1198         fl6->flowi6_oif = p->link;
1199         fl6->flowlabel = 0;
1200
1201         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1202                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1203         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1204                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1205
1206         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1207         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1208
1209         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1210                 dev->flags |= IFF_POINTOPOINT;
1211         else
1212                 dev->flags &= ~IFF_POINTOPOINT;
1213
1214         dev->iflink = p->link;
1215
1216         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1217                 int strict = (ipv6_addr_type(&p->raddr) &
1218                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1219
1220                 struct rt6_info *rt = rt6_lookup(t->net,
1221                                                  &p->raddr, &p->laddr,
1222                                                  p->link, strict);
1223
1224                 if (rt == NULL)
1225                         return;
1226
1227                 if (rt->dst.dev) {
1228                         dev->hard_header_len = rt->dst.dev->hard_header_len +
1229                                 sizeof (struct ipv6hdr);
1230
1231                         dev->mtu = rt->dst.dev->mtu - sizeof (struct ipv6hdr);
1232                         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1233                                 dev->mtu-=8;
1234
1235                         if (dev->mtu < IPV6_MIN_MTU)
1236                                 dev->mtu = IPV6_MIN_MTU;
1237                 }
1238                 ip6_rt_put(rt);
1239         }
1240 }
1241
1242 /**
1243  * ip6_tnl_change - update the tunnel parameters
1244  *   @t: tunnel to be changed
1245  *   @p: tunnel configuration parameters
1246  *
1247  * Description:
1248  *   ip6_tnl_change() updates the tunnel parameters
1249  **/
1250
1251 static int
1252 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1253 {
1254         t->parms.laddr = p->laddr;
1255         t->parms.raddr = p->raddr;
1256         t->parms.flags = p->flags;
1257         t->parms.hop_limit = p->hop_limit;
1258         t->parms.encap_limit = p->encap_limit;
1259         t->parms.flowinfo = p->flowinfo;
1260         t->parms.link = p->link;
1261         t->parms.proto = p->proto;
1262         ip6_tnl_dst_reset(t);
1263         ip6_tnl_link_config(t);
1264         return 0;
1265 }
1266
1267 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1268 {
1269         struct net *net = t->net;
1270         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1271         int err;
1272
1273         ip6_tnl_unlink(ip6n, t);
1274         synchronize_net();
1275         err = ip6_tnl_change(t, p);
1276         ip6_tnl_link(ip6n, t);
1277         netdev_state_change(t->dev);
1278         return err;
1279 }
1280
1281 static void
1282 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1283 {
1284         p->laddr = u->laddr;
1285         p->raddr = u->raddr;
1286         p->flags = u->flags;
1287         p->hop_limit = u->hop_limit;
1288         p->encap_limit = u->encap_limit;
1289         p->flowinfo = u->flowinfo;
1290         p->link = u->link;
1291         p->proto = u->proto;
1292         memcpy(p->name, u->name, sizeof(u->name));
1293 }
1294
1295 static void
1296 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1297 {
1298         u->laddr = p->laddr;
1299         u->raddr = p->raddr;
1300         u->flags = p->flags;
1301         u->hop_limit = p->hop_limit;
1302         u->encap_limit = p->encap_limit;
1303         u->flowinfo = p->flowinfo;
1304         u->link = p->link;
1305         u->proto = p->proto;
1306         memcpy(u->name, p->name, sizeof(u->name));
1307 }
1308
1309 /**
1310  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1311  *   @dev: virtual device associated with tunnel
1312  *   @ifr: parameters passed from userspace
1313  *   @cmd: command to be performed
1314  *
1315  * Description:
1316  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1317  *   from userspace.
1318  *
1319  *   The possible commands are the following:
1320  *     %SIOCGETTUNNEL: get tunnel parameters for device
1321  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1322  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1323  *     %SIOCDELTUNNEL: delete tunnel
1324  *
1325  *   The fallback device "ip6tnl0", created during module
1326  *   initialization, can be used for creating other tunnel devices.
1327  *
1328  * Return:
1329  *   0 on success,
1330  *   %-EFAULT if unable to copy data to or from userspace,
1331  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1332  *   %-EINVAL if passed tunnel parameters are invalid,
1333  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1334  *   %-ENODEV if attempting to change or delete a nonexisting device
1335  **/
1336
1337 static int
1338 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1339 {
1340         int err = 0;
1341         struct ip6_tnl_parm p;
1342         struct __ip6_tnl_parm p1;
1343         struct ip6_tnl *t = NULL;
1344         struct net *net = dev_net(dev);
1345         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1346
1347         switch (cmd) {
1348         case SIOCGETTUNNEL:
1349                 if (dev == ip6n->fb_tnl_dev) {
1350                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) {
1351                                 err = -EFAULT;
1352                                 break;
1353                         }
1354                         ip6_tnl_parm_from_user(&p1, &p);
1355                         t = ip6_tnl_locate(net, &p1, 0);
1356                 } else {
1357                         memset(&p, 0, sizeof(p));
1358                 }
1359                 if (t == NULL)
1360                         t = netdev_priv(dev);
1361                 ip6_tnl_parm_to_user(&p, &t->parms);
1362                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) {
1363                         err = -EFAULT;
1364                 }
1365                 break;
1366         case SIOCADDTUNNEL:
1367         case SIOCCHGTUNNEL:
1368                 err = -EPERM;
1369                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1370                         break;
1371                 err = -EFAULT;
1372                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1373                         break;
1374                 err = -EINVAL;
1375                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1376                     p.proto != 0)
1377                         break;
1378                 ip6_tnl_parm_from_user(&p1, &p);
1379                 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1380                 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
1381                         if (t != NULL) {
1382                                 if (t->dev != dev) {
1383                                         err = -EEXIST;
1384                                         break;
1385                                 }
1386                         } else
1387                                 t = netdev_priv(dev);
1388
1389                         err = ip6_tnl_update(t, &p1);
1390                 }
1391                 if (t) {
1392                         err = 0;
1393                         ip6_tnl_parm_to_user(&p, &t->parms);
1394                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1395                                 err = -EFAULT;
1396
1397                 } else
1398                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1399                 break;
1400         case SIOCDELTUNNEL:
1401                 err = -EPERM;
1402                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1403                         break;
1404
1405                 if (dev == ip6n->fb_tnl_dev) {
1406                         err = -EFAULT;
1407                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1408                                 break;
1409                         err = -ENOENT;
1410                         ip6_tnl_parm_from_user(&p1, &p);
1411                         t = ip6_tnl_locate(net, &p1, 0);
1412                         if (t == NULL)
1413                                 break;
1414                         err = -EPERM;
1415                         if (t->dev == ip6n->fb_tnl_dev)
1416                                 break;
1417                         dev = t->dev;
1418                 }
1419                 err = 0;
1420                 unregister_netdevice(dev);
1421                 break;
1422         default:
1423                 err = -EINVAL;
1424         }
1425         return err;
1426 }
1427
1428 /**
1429  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1430  *   @dev: virtual device associated with tunnel
1431  *   @new_mtu: the new mtu
1432  *
1433  * Return:
1434  *   0 on success,
1435  *   %-EINVAL if mtu too small
1436  **/
1437
1438 static int
1439 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1440 {
1441         struct ip6_tnl *tnl = netdev_priv(dev);
1442
1443         if (tnl->parms.proto == IPPROTO_IPIP) {
1444                 if (new_mtu < 68)
1445                         return -EINVAL;
1446         } else {
1447                 if (new_mtu < IPV6_MIN_MTU)
1448                         return -EINVAL;
1449         }
1450         if (new_mtu > 0xFFF8 - dev->hard_header_len)
1451                 return -EINVAL;
1452         dev->mtu = new_mtu;
1453         return 0;
1454 }
1455
1456
1457 static const struct net_device_ops ip6_tnl_netdev_ops = {
1458         .ndo_uninit     = ip6_tnl_dev_uninit,
1459         .ndo_start_xmit = ip6_tnl_xmit,
1460         .ndo_do_ioctl   = ip6_tnl_ioctl,
1461         .ndo_change_mtu = ip6_tnl_change_mtu,
1462         .ndo_get_stats  = ip6_get_stats,
1463 };
1464
1465
1466 /**
1467  * ip6_tnl_dev_setup - setup virtual tunnel device
1468  *   @dev: virtual device associated with tunnel
1469  *
1470  * Description:
1471  *   Initialize function pointers and device parameters
1472  **/
1473
1474 static void ip6_tnl_dev_setup(struct net_device *dev)
1475 {
1476         struct ip6_tnl *t;
1477
1478         dev->netdev_ops = &ip6_tnl_netdev_ops;
1479         dev->destructor = ip6_dev_free;
1480
1481         dev->type = ARPHRD_TUNNEL6;
1482         dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr);
1483         dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr);
1484         t = netdev_priv(dev);
1485         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1486                 dev->mtu-=8;
1487         dev->flags |= IFF_NOARP;
1488         dev->addr_len = sizeof(struct in6_addr);
1489         dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1490         /* This perm addr will be used as interface identifier by IPv6 */
1491         dev->addr_assign_type = NET_ADDR_RANDOM;
1492         eth_random_addr(dev->perm_addr);
1493 }
1494
1495
1496 /**
1497  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1498  *   @dev: virtual device associated with tunnel
1499  **/
1500
1501 static inline int
1502 ip6_tnl_dev_init_gen(struct net_device *dev)
1503 {
1504         struct ip6_tnl *t = netdev_priv(dev);
1505         int i;
1506
1507         t->dev = dev;
1508         t->net = dev_net(dev);
1509         dev->tstats = alloc_percpu(struct pcpu_sw_netstats);
1510         if (!dev->tstats)
1511                 return -ENOMEM;
1512
1513         for_each_possible_cpu(i) {
1514                 struct pcpu_sw_netstats *ip6_tnl_stats;
1515                 ip6_tnl_stats = per_cpu_ptr(dev->tstats, i);
1516                 u64_stats_init(&ip6_tnl_stats->syncp);
1517         }
1518         return 0;
1519 }
1520
1521 /**
1522  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1523  *   @dev: virtual device associated with tunnel
1524  **/
1525
1526 static int ip6_tnl_dev_init(struct net_device *dev)
1527 {
1528         struct ip6_tnl *t = netdev_priv(dev);
1529         int err = ip6_tnl_dev_init_gen(dev);
1530
1531         if (err)
1532                 return err;
1533         ip6_tnl_link_config(t);
1534         return 0;
1535 }
1536
1537 /**
1538  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1539  *   @dev: fallback device
1540  *
1541  * Return: 0
1542  **/
1543
1544 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1545 {
1546         struct ip6_tnl *t = netdev_priv(dev);
1547         struct net *net = dev_net(dev);
1548         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1549         int err = ip6_tnl_dev_init_gen(dev);
1550
1551         if (err)
1552                 return err;
1553
1554         t->parms.proto = IPPROTO_IPV6;
1555         dev_hold(dev);
1556
1557         ip6_tnl_link_config(t);
1558
1559         rcu_assign_pointer(ip6n->tnls_wc[0], t);
1560         return 0;
1561 }
1562
1563 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[])
1564 {
1565         u8 proto;
1566
1567         if (!data)
1568                 return 0;
1569
1570         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1571         if (proto != IPPROTO_IPV6 &&
1572             proto != IPPROTO_IPIP &&
1573             proto != 0)
1574                 return -EINVAL;
1575
1576         return 0;
1577 }
1578
1579 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1580                                   struct __ip6_tnl_parm *parms)
1581 {
1582         memset(parms, 0, sizeof(*parms));
1583
1584         if (!data)
1585                 return;
1586
1587         if (data[IFLA_IPTUN_LINK])
1588                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1589
1590         if (data[IFLA_IPTUN_LOCAL])
1591                 nla_memcpy(&parms->laddr, data[IFLA_IPTUN_LOCAL],
1592                            sizeof(struct in6_addr));
1593
1594         if (data[IFLA_IPTUN_REMOTE])
1595                 nla_memcpy(&parms->raddr, data[IFLA_IPTUN_REMOTE],
1596                            sizeof(struct in6_addr));
1597
1598         if (data[IFLA_IPTUN_TTL])
1599                 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1600
1601         if (data[IFLA_IPTUN_ENCAP_LIMIT])
1602                 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1603
1604         if (data[IFLA_IPTUN_FLOWINFO])
1605                 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1606
1607         if (data[IFLA_IPTUN_FLAGS])
1608                 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1609
1610         if (data[IFLA_IPTUN_PROTO])
1611                 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1612 }
1613
1614 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
1615                            struct nlattr *tb[], struct nlattr *data[])
1616 {
1617         struct net *net = dev_net(dev);
1618         struct ip6_tnl *nt;
1619
1620         nt = netdev_priv(dev);
1621         ip6_tnl_netlink_parms(data, &nt->parms);
1622
1623         if (ip6_tnl_locate(net, &nt->parms, 0))
1624                 return -EEXIST;
1625
1626         return ip6_tnl_create2(dev);
1627 }
1628
1629 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
1630                               struct nlattr *data[])
1631 {
1632         struct ip6_tnl *t = netdev_priv(dev);
1633         struct __ip6_tnl_parm p;
1634         struct net *net = t->net;
1635         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1636
1637         if (dev == ip6n->fb_tnl_dev)
1638                 return -EINVAL;
1639
1640         ip6_tnl_netlink_parms(data, &p);
1641
1642         t = ip6_tnl_locate(net, &p, 0);
1643
1644         if (t) {
1645                 if (t->dev != dev)
1646                         return -EEXIST;
1647         } else
1648                 t = netdev_priv(dev);
1649
1650         return ip6_tnl_update(t, &p);
1651 }
1652
1653 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
1654 {
1655         struct net *net = dev_net(dev);
1656         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1657
1658         if (dev != ip6n->fb_tnl_dev)
1659                 unregister_netdevice_queue(dev, head);
1660 }
1661
1662 static size_t ip6_tnl_get_size(const struct net_device *dev)
1663 {
1664         return
1665                 /* IFLA_IPTUN_LINK */
1666                 nla_total_size(4) +
1667                 /* IFLA_IPTUN_LOCAL */
1668                 nla_total_size(sizeof(struct in6_addr)) +
1669                 /* IFLA_IPTUN_REMOTE */
1670                 nla_total_size(sizeof(struct in6_addr)) +
1671                 /* IFLA_IPTUN_TTL */
1672                 nla_total_size(1) +
1673                 /* IFLA_IPTUN_ENCAP_LIMIT */
1674                 nla_total_size(1) +
1675                 /* IFLA_IPTUN_FLOWINFO */
1676                 nla_total_size(4) +
1677                 /* IFLA_IPTUN_FLAGS */
1678                 nla_total_size(4) +
1679                 /* IFLA_IPTUN_PROTO */
1680                 nla_total_size(1) +
1681                 0;
1682 }
1683
1684 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
1685 {
1686         struct ip6_tnl *tunnel = netdev_priv(dev);
1687         struct __ip6_tnl_parm *parm = &tunnel->parms;
1688
1689         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1690             nla_put(skb, IFLA_IPTUN_LOCAL, sizeof(struct in6_addr),
1691                     &parm->laddr) ||
1692             nla_put(skb, IFLA_IPTUN_REMOTE, sizeof(struct in6_addr),
1693                     &parm->raddr) ||
1694             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
1695             nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
1696             nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
1697             nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
1698             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto))
1699                 goto nla_put_failure;
1700         return 0;
1701
1702 nla_put_failure:
1703         return -EMSGSIZE;
1704 }
1705
1706 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
1707         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
1708         [IFLA_IPTUN_LOCAL]              = { .len = sizeof(struct in6_addr) },
1709         [IFLA_IPTUN_REMOTE]             = { .len = sizeof(struct in6_addr) },
1710         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
1711         [IFLA_IPTUN_ENCAP_LIMIT]        = { .type = NLA_U8 },
1712         [IFLA_IPTUN_FLOWINFO]           = { .type = NLA_U32 },
1713         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U32 },
1714         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
1715 };
1716
1717 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
1718         .kind           = "ip6tnl",
1719         .maxtype        = IFLA_IPTUN_MAX,
1720         .policy         = ip6_tnl_policy,
1721         .priv_size      = sizeof(struct ip6_tnl),
1722         .setup          = ip6_tnl_dev_setup,
1723         .validate       = ip6_tnl_validate,
1724         .newlink        = ip6_tnl_newlink,
1725         .changelink     = ip6_tnl_changelink,
1726         .dellink        = ip6_tnl_dellink,
1727         .get_size       = ip6_tnl_get_size,
1728         .fill_info      = ip6_tnl_fill_info,
1729 };
1730
1731 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
1732         .handler        = ip4ip6_rcv,
1733         .err_handler    = ip4ip6_err,
1734         .priority       =       1,
1735 };
1736
1737 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
1738         .handler        = ip6ip6_rcv,
1739         .err_handler    = ip6ip6_err,
1740         .priority       =       1,
1741 };
1742
1743 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net)
1744 {
1745         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1746         struct net_device *dev, *aux;
1747         int h;
1748         struct ip6_tnl *t;
1749         LIST_HEAD(list);
1750
1751         for_each_netdev_safe(net, dev, aux)
1752                 if (dev->rtnl_link_ops == &ip6_link_ops)
1753                         unregister_netdevice_queue(dev, &list);
1754
1755         for (h = 0; h < HASH_SIZE; h++) {
1756                 t = rtnl_dereference(ip6n->tnls_r_l[h]);
1757                 while (t != NULL) {
1758                         /* If dev is in the same netns, it has already
1759                          * been added to the list by the previous loop.
1760                          */
1761                         if (!net_eq(dev_net(t->dev), net))
1762                                 unregister_netdevice_queue(t->dev, &list);
1763                         t = rtnl_dereference(t->next);
1764                 }
1765         }
1766
1767         unregister_netdevice_many(&list);
1768 }
1769
1770 static int __net_init ip6_tnl_init_net(struct net *net)
1771 {
1772         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1773         struct ip6_tnl *t = NULL;
1774         int err;
1775
1776         ip6n->tnls[0] = ip6n->tnls_wc;
1777         ip6n->tnls[1] = ip6n->tnls_r_l;
1778
1779         err = -ENOMEM;
1780         ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
1781                                       ip6_tnl_dev_setup);
1782
1783         if (!ip6n->fb_tnl_dev)
1784                 goto err_alloc_dev;
1785         dev_net_set(ip6n->fb_tnl_dev, net);
1786         ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
1787         /* FB netdevice is special: we have one, and only one per netns.
1788          * Allowing to move it to another netns is clearly unsafe.
1789          */
1790         ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
1791
1792         err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
1793         if (err < 0)
1794                 goto err_register;
1795
1796         err = register_netdev(ip6n->fb_tnl_dev);
1797         if (err < 0)
1798                 goto err_register;
1799
1800         t = netdev_priv(ip6n->fb_tnl_dev);
1801
1802         strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
1803         return 0;
1804
1805 err_register:
1806         ip6_dev_free(ip6n->fb_tnl_dev);
1807 err_alloc_dev:
1808         return err;
1809 }
1810
1811 static void __net_exit ip6_tnl_exit_net(struct net *net)
1812 {
1813         rtnl_lock();
1814         ip6_tnl_destroy_tunnels(net);
1815         rtnl_unlock();
1816 }
1817
1818 static struct pernet_operations ip6_tnl_net_ops = {
1819         .init = ip6_tnl_init_net,
1820         .exit = ip6_tnl_exit_net,
1821         .id   = &ip6_tnl_net_id,
1822         .size = sizeof(struct ip6_tnl_net),
1823 };
1824
1825 /**
1826  * ip6_tunnel_init - register protocol and reserve needed resources
1827  *
1828  * Return: 0 on success
1829  **/
1830
1831 static int __init ip6_tunnel_init(void)
1832 {
1833         int  err;
1834
1835         err = register_pernet_device(&ip6_tnl_net_ops);
1836         if (err < 0)
1837                 goto out_pernet;
1838
1839         err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
1840         if (err < 0) {
1841                 pr_err("%s: can't register ip4ip6\n", __func__);
1842                 goto out_ip4ip6;
1843         }
1844
1845         err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
1846         if (err < 0) {
1847                 pr_err("%s: can't register ip6ip6\n", __func__);
1848                 goto out_ip6ip6;
1849         }
1850         err = rtnl_link_register(&ip6_link_ops);
1851         if (err < 0)
1852                 goto rtnl_link_failed;
1853
1854         return 0;
1855
1856 rtnl_link_failed:
1857         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
1858 out_ip6ip6:
1859         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
1860 out_ip4ip6:
1861         unregister_pernet_device(&ip6_tnl_net_ops);
1862 out_pernet:
1863         return err;
1864 }
1865
1866 /**
1867  * ip6_tunnel_cleanup - free resources and unregister protocol
1868  **/
1869
1870 static void __exit ip6_tunnel_cleanup(void)
1871 {
1872         rtnl_link_unregister(&ip6_link_ops);
1873         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
1874                 pr_info("%s: can't deregister ip4ip6\n", __func__);
1875
1876         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
1877                 pr_info("%s: can't deregister ip6ip6\n", __func__);
1878
1879         unregister_pernet_device(&ip6_tnl_net_ops);
1880 }
1881
1882 module_init(ip6_tunnel_init);
1883 module_exit(ip6_tunnel_cleanup);