net/ipv6/ip6_tunnel.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      IPv6 tunneling device
   4  *      Linux INET6 implementation
   5  *
   6  *      Authors:
   7  *      Ville Nuorvala          <vnuorval@tcs.hut.fi>
   8  *      Yasuyuki Kozakai        <kozakai@linux-ipv6.org>
   9  *
  10  *      Based on:
  11  *      linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
  12  *
  13  *      RFC 2473
  14  */
  15
  16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  17
  18 #include <linux/module.h>
  19 #include <linux/capability.h>
  20 #include <linux/errno.h>
  21 #include <linux/types.h>
  22 #include <linux/sockios.h>
  23 #include <linux/icmp.h>
  24 #include <linux/if.h>
  25 #include <linux/in.h>
  26 #include <linux/ip.h>
  27 #include <linux/net.h>
  28 #include <linux/in6.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/if_arp.h>
  31 #include <linux/icmpv6.h>
  32 #include <linux/init.h>
  33 #include <linux/route.h>
  34 #include <linux/rtnetlink.h>
  35 #include <linux/netfilter_ipv6.h>
  36 #include <linux/slab.h>
  37 #include <linux/hash.h>
  38 #include <linux/etherdevice.h>
  39
  40 #include <linux/uaccess.h>
  41 #include <linux/atomic.h>
  42
  43 #include <net/icmp.h>
  44 #include <net/ip.h>
  45 #include <net/ip_tunnels.h>
  46 #include <net/ipv6.h>
  47 #include <net/ip6_route.h>
  48 #include <net/addrconf.h>
  49 #include <net/ip6_tunnel.h>
  50 #include <net/xfrm.h>
  51 #include <net/dsfield.h>
  52 #include <net/inet_ecn.h>
  53 #include <net/net_namespace.h>
  54 #include <net/netns/generic.h>
  55 #include <net/dst_metadata.h>
  56
  57 MODULE_AUTHOR("Ville Nuorvala");
  58 MODULE_DESCRIPTION("IPv6 tunneling device");
  59 MODULE_LICENSE("GPL");
  60 MODULE_ALIAS_RTNL_LINK("ip6tnl");
  61 MODULE_ALIAS_NETDEV("ip6tnl0");
  62
  63 #define IP6_TUNNEL_HASH_SIZE_SHIFT  5
  64 #define IP6_TUNNEL_HASH_SIZE (1 << IP6_TUNNEL_HASH_SIZE_SHIFT)
  65
  66 static bool log_ecn_error = true;
  67 module_param(log_ecn_error, bool, 0644);
  68 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  69
  70 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
  71 {
  72         u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
  73
  74         return hash_32(hash, IP6_TUNNEL_HASH_SIZE_SHIFT);
  75 }
  76
  77 static int ip6_tnl_dev_init(struct net_device *dev);
  78 static void ip6_tnl_dev_setup(struct net_device *dev);
  79 static struct rtnl_link_ops ip6_link_ops __read_mostly;
  80
  81 static unsigned int ip6_tnl_net_id __read_mostly;
  82 struct ip6_tnl_net {
  83         /* the IPv6 tunnel fallback device */
  84         struct net_device *fb_tnl_dev;
  85         /* lists for storing tunnels in use */
  86         struct ip6_tnl __rcu *tnls_r_l[IP6_TUNNEL_HASH_SIZE];
  87         struct ip6_tnl __rcu *tnls_wc[1];
  88         struct ip6_tnl __rcu **tnls[2];
  89         struct ip6_tnl __rcu *collect_md_tun;
  90 };
  91
  92 static inline int ip6_tnl_mpls_supported(void)
  93 {
  94         return IS_ENABLED(CONFIG_MPLS);
  95 }
  96
  97 static struct net_device_stats *ip6_get_stats(struct net_device *dev)
  98 {
  99         struct pcpu_sw_netstats tmp, sum = { 0 };
 100         int i;
 101
 102         for_each_possible_cpu(i) {
 103                 unsigned int start;
 104                 const struct pcpu_sw_netstats *tstats =
 105                                                    per_cpu_ptr(dev->tstats, i);
 106
 107                 do {
 108                         start = u64_stats_fetch_begin_irq(&tstats->syncp);
 109                         tmp.rx_packets = tstats->rx_packets;
 110                         tmp.rx_bytes = tstats->rx_bytes;
 111                         tmp.tx_packets = tstats->tx_packets;
 112                         tmp.tx_bytes =  tstats->tx_bytes;
 113                 } while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
 114
 115                 sum.rx_packets += tmp.rx_packets;
 116                 sum.rx_bytes   += tmp.rx_bytes;
 117                 sum.tx_packets += tmp.tx_packets;
 118                 sum.tx_bytes   += tmp.tx_bytes;
 119         }
 120         dev->stats.rx_packets = sum.rx_packets;
 121         dev->stats.rx_bytes   = sum.rx_bytes;
 122         dev->stats.tx_packets = sum.tx_packets;
 123         dev->stats.tx_bytes   = sum.tx_bytes;
 124         return &dev->stats;
 125 }
 126
 127 #define for_each_ip6_tunnel_rcu(start) \
 128         for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
 129
 130 /**
 131  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
 132  *   @net: network namespace
 133  *   @link: ifindex of underlying interface
 134  *   @remote: the address of the tunnel exit-point
 135  *   @local: the address of the tunnel entry-point
 136  *
 137  * Return:
 138  *   tunnel matching given end-points if found,
 139  *   else fallback tunnel if its device is up,
 140  *   else %NULL
 141  **/
 142
 143 static struct ip6_tnl *
 144 ip6_tnl_lookup(struct net *net, int link,
 145                const struct in6_addr *remote, const struct in6_addr *local)
 146 {
 147         unsigned int hash = HASH(remote, local);
 148         struct ip6_tnl *t, *cand = NULL;
 149         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 150         struct in6_addr any;
 151
 152         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 153                 if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 154                     !ipv6_addr_equal(remote, &t->parms.raddr) ||
 155                     !(t->dev->flags & IFF_UP))
 156                         continue;
 157
 158                 if (link == t->parms.link)
 159                         return t;
 160                 else
 161                         cand = t;
 162         }
 163
 164         memset(&any, 0, sizeof(any));
 165         hash = HASH(&any, local);
 166         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 167                 if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 168                     !ipv6_addr_any(&t->parms.raddr) ||
 169                     !(t->dev->flags & IFF_UP))
 170                         continue;
 171
 172                 if (link == t->parms.link)
 173                         return t;
 174                 else if (!cand)
 175                         cand = t;
 176         }
 177
 178         hash = HASH(remote, &any);
 179         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 180                 if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
 181                     !ipv6_addr_any(&t->parms.laddr) ||
 182                     !(t->dev->flags & IFF_UP))
 183                         continue;
 184
 185                 if (link == t->parms.link)
 186                         return t;
 187                 else if (!cand)
 188                         cand = t;
 189         }
 190
 191         if (cand)
 192                 return cand;
 193
 194         t = rcu_dereference(ip6n->collect_md_tun);
 195         if (t && t->dev->flags & IFF_UP)
 196                 return t;
 197
 198         t = rcu_dereference(ip6n->tnls_wc[0]);
 199         if (t && (t->dev->flags & IFF_UP))
 200                 return t;
 201
 202         return NULL;
 203 }
 204
 205 /**
 206  * ip6_tnl_bucket - get head of list matching given tunnel parameters
 207  *   @p: parameters containing tunnel end-points
 208  *
 209  * Description:
 210  *   ip6_tnl_bucket() returns the head of the list matching the
 211  *   &struct in6_addr entries laddr and raddr in @p.
 212  *
 213  * Return: head of IPv6 tunnel list
 214  **/
 215
 216 static struct ip6_tnl __rcu **
 217 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
 218 {
 219         const struct in6_addr *remote = &p->raddr;
 220         const struct in6_addr *local = &p->laddr;
 221         unsigned int h = 0;
 222         int prio = 0;
 223
 224         if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
 225                 prio = 1;
 226                 h = HASH(remote, local);
 227         }
 228         return &ip6n->tnls[prio][h];
 229 }
 230
 231 /**
 232  * ip6_tnl_link - add tunnel to hash table
 233  *   @t: tunnel to be added
 234  **/
 235
 236 static void
 237 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 238 {
 239         struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
 240
 241         if (t->parms.collect_md)
 242                 rcu_assign_pointer(ip6n->collect_md_tun, t);
 243         rcu_assign_pointer(t->next , rtnl_dereference(*tp));
 244         rcu_assign_pointer(*tp, t);
 245 }
 246
 247 /**
 248  * ip6_tnl_unlink - remove tunnel from hash table
 249  *   @t: tunnel to be removed
 250  **/
 251
 252 static void
 253 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 254 {
 255         struct ip6_tnl __rcu **tp;
 256         struct ip6_tnl *iter;
 257
 258         if (t->parms.collect_md)
 259                 rcu_assign_pointer(ip6n->collect_md_tun, NULL);
 260
 261         for (tp = ip6_tnl_bucket(ip6n, &t->parms);
 262              (iter = rtnl_dereference(*tp)) != NULL;
 263              tp = &iter->next) {
 264                 if (t == iter) {
 265                         rcu_assign_pointer(*tp, t->next);
 266                         break;
 267                 }
 268         }
 269 }
 270
 271 static void ip6_dev_free(struct net_device *dev)
 272 {
 273         struct ip6_tnl *t = netdev_priv(dev);
 274
 275         gro_cells_destroy(&t->gro_cells);
 276         dst_cache_destroy(&t->dst_cache);
 277         free_percpu(dev->tstats);
 278 }
 279
 280 static int ip6_tnl_create2(struct net_device *dev)
 281 {
 282         struct ip6_tnl *t = netdev_priv(dev);
 283         struct net *net = dev_net(dev);
 284         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 285         int err;
 286
 287         t = netdev_priv(dev);
 288
 289         dev->rtnl_link_ops = &ip6_link_ops;
 290         err = register_netdevice(dev);
 291         if (err < 0)
 292                 goto out;
 293
 294         strcpy(t->parms.name, dev->name);
 295
 296         ip6_tnl_link(ip6n, t);
 297         return 0;
 298
 299 out:
 300         return err;
 301 }
 302
 303 /**
 304  * ip6_tnl_create - create a new tunnel
 305  *   @net: network namespace
 306  *   @p: tunnel parameters
 307  *
 308  * Description:
 309  *   Create tunnel matching given parameters.
 310  *
 311  * Return:
 312  *   created tunnel or error pointer
 313  **/
 314
 315 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
 316 {
 317         struct net_device *dev;
 318         struct ip6_tnl *t;
 319         char name[IFNAMSIZ];
 320         int err = -E2BIG;
 321
 322         if (p->name[0]) {
 323                 if (!dev_valid_name(p->name))
 324                         goto failed;
 325                 strlcpy(name, p->name, IFNAMSIZ);
 326         } else {
 327                 sprintf(name, "ip6tnl%%d");
 328         }
 329         err = -ENOMEM;
 330         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 331                            ip6_tnl_dev_setup);
 332         if (!dev)
 333                 goto failed;
 334
 335         dev_net_set(dev, net);
 336
 337         t = netdev_priv(dev);
 338         t->parms = *p;
 339         t->net = dev_net(dev);
 340         err = ip6_tnl_create2(dev);
 341         if (err < 0)
 342                 goto failed_free;
 343
 344         return t;
 345
 346 failed_free:
 347         free_netdev(dev);
 348 failed:
 349         return ERR_PTR(err);
 350 }
 351
 352 /**
 353  * ip6_tnl_locate - find or create tunnel matching given parameters
 354  *   @net: network namespace
 355  *   @p: tunnel parameters
 356  *   @create: != 0 if allowed to create new tunnel if no match found
 357  *
 358  * Description:
 359  *   ip6_tnl_locate() first tries to locate an existing tunnel
 360  *   based on @parms. If this is unsuccessful, but @create is set a new
 361  *   tunnel device is created and registered for use.
 362  *
 363  * Return:
 364  *   matching tunnel or error pointer
 365  **/
 366
 367 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
 368                 struct __ip6_tnl_parm *p, int create)
 369 {
 370         const struct in6_addr *remote = &p->raddr;
 371         const struct in6_addr *local = &p->laddr;
 372         struct ip6_tnl __rcu **tp;
 373         struct ip6_tnl *t;
 374         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 375
 376         for (tp = ip6_tnl_bucket(ip6n, p);
 377              (t = rtnl_dereference(*tp)) != NULL;
 378              tp = &t->next) {
 379                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 380                     ipv6_addr_equal(remote, &t->parms.raddr) &&
 381                     p->link == t->parms.link) {
 382                         if (create)
 383                                 return ERR_PTR(-EEXIST);
 384
 385                         return t;
 386                 }
 387         }
 388         if (!create)
 389                 return ERR_PTR(-ENODEV);
 390         return ip6_tnl_create(net, p);
 391 }
 392
 393 /**
 394  * ip6_tnl_dev_uninit - tunnel device uninitializer
 395  *   @dev: the device to be destroyed
 396  *
 397  * Description:
 398  *   ip6_tnl_dev_uninit() removes tunnel from its list
 399  **/
 400
 401 static void
 402 ip6_tnl_dev_uninit(struct net_device *dev)
 403 {
 404         struct ip6_tnl *t = netdev_priv(dev);
 405         struct net *net = t->net;
 406         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 407
 408         if (dev == ip6n->fb_tnl_dev)
 409                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
 410         else
 411                 ip6_tnl_unlink(ip6n, t);
 412         dst_cache_reset(&t->dst_cache);
 413         dev_put(dev);
 414 }
 415
 416 /**
 417  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
 418  *   @skb: received socket buffer
 419  *
 420  * Return:
 421  *   0 if none was found,
 422  *   else index to encapsulation limit
 423  **/
 424
 425 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
 426 {
 427         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)raw;
 428         unsigned int nhoff = raw - skb->data;
 429         unsigned int off = nhoff + sizeof(*ipv6h);
 430         u8 nexthdr = ipv6h->nexthdr;
 431
 432         while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
 433                 struct ipv6_opt_hdr *hdr;
 434                 u16 optlen;
 435
 436                 if (!pskb_may_pull(skb, off + sizeof(*hdr)))
 437                         break;
 438
 439                 hdr = (struct ipv6_opt_hdr *)(skb->data + off);
 440                 if (nexthdr == NEXTHDR_FRAGMENT) {
 441                         optlen = 8;
 442                 } else if (nexthdr == NEXTHDR_AUTH) {
 443                         optlen = ipv6_authlen(hdr);
 444                 } else {
 445                         optlen = ipv6_optlen(hdr);
 446                 }
 447
 448                 if (!pskb_may_pull(skb, off + optlen))
 449                         break;
 450
 451                 hdr = (struct ipv6_opt_hdr *)(skb->data + off);
 452                 if (nexthdr == NEXTHDR_FRAGMENT) {
 453                         struct frag_hdr *frag_hdr = (struct frag_hdr *)hdr;
 454
 455                         if (frag_hdr->frag_off)
 456                                 break;
 457                 }
 458                 if (nexthdr == NEXTHDR_DEST) {
 459                         u16 i = 2;
 460
 461                         while (1) {
 462                                 struct ipv6_tlv_tnl_enc_lim *tel;
 463
 464                                 /* No more room for encapsulation limit */
 465                                 if (i + sizeof(*tel) > optlen)
 466                                         break;
 467
 468                                 tel = (struct ipv6_tlv_tnl_enc_lim *)(skb->data + off + i);
 469                                 /* return index of option if found and valid */
 470                                 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
 471                                     tel->length == 1)
 472                                         return i + off - nhoff;
 473                                 /* else jump to next option */
 474                                 if (tel->type)
 475                                         i += tel->length + 2;
 476                                 else
 477                                         i++;
 478                         }
 479                 }
 480                 nexthdr = hdr->nexthdr;
 481                 off += optlen;
 482         }
 483         return 0;
 484 }
 485 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
 486
 487 /**
 488  * ip6_tnl_err - tunnel error handler
 489  *
 490  * Description:
 491  *   ip6_tnl_err() should handle errors in the tunnel according
 492  *   to the specifications in RFC 2473.
 493  **/
 494
 495 static int
 496 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
 497             u8 *type, u8 *code, int *msg, __u32 *info, int offset)
 498 {
 499         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 500         struct net *net = dev_net(skb->dev);
 501         u8 rel_type = ICMPV6_DEST_UNREACH;
 502         u8 rel_code = ICMPV6_ADDR_UNREACH;
 503         __u32 rel_info = 0;
 504         struct ip6_tnl *t;
 505         int err = -ENOENT;
 506         int rel_msg = 0;
 507         u8 tproto;
 508         __u16 len;
 509
 510         /* If the packet doesn't contain the original IPv6 header we are
 511            in trouble since we might need the source address for further
 512            processing of the error. */
 513
 514         rcu_read_lock();
 515         t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->daddr, &ipv6h->saddr);
 516         if (!t)
 517                 goto out;
 518
 519         tproto = READ_ONCE(t->parms.proto);
 520         if (tproto != ipproto && tproto != 0)
 521                 goto out;
 522
 523         err = 0;
 524
 525         switch (*type) {
 526         case ICMPV6_DEST_UNREACH:
 527                 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
 528                                     t->parms.name);
 529                 rel_msg = 1;
 530                 break;
 531         case ICMPV6_TIME_EXCEED:
 532                 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
 533                         net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 534                                             t->parms.name);
 535                         rel_msg = 1;
 536                 }
 537                 break;
 538         case ICMPV6_PARAMPROB: {
 539                 struct ipv6_tlv_tnl_enc_lim *tel;
 540                 __u32 teli;
 541
 542                 teli = 0;
 543                 if ((*code) == ICMPV6_HDR_FIELD)
 544                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 545
 546                 if (teli && teli == *info - 2) {
 547                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 548                         if (tel->encap_limit == 0) {
 549                                 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 550                                                     t->parms.name);
 551                                 rel_msg = 1;
 552                         }
 553                 } else {
 554                         net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 555                                             t->parms.name);
 556                 }
 557                 break;
 558         }
 559         case ICMPV6_PKT_TOOBIG: {
 560                 __u32 mtu;
 561
 562                 ip6_update_pmtu(skb, net, htonl(*info), 0, 0,
 563                                 sock_net_uid(net, NULL));
 564                 mtu = *info - offset;
 565                 if (mtu < IPV6_MIN_MTU)
 566                         mtu = IPV6_MIN_MTU;
 567                 len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
 568                 if (len > mtu) {
 569                         rel_type = ICMPV6_PKT_TOOBIG;
 570                         rel_code = 0;
 571                         rel_info = mtu;
 572                         rel_msg = 1;
 573                 }
 574                 break;
 575         }
 576         case NDISC_REDIRECT:
 577                 ip6_redirect(skb, net, skb->dev->ifindex, 0,
 578                              sock_net_uid(net, NULL));
 579                 break;
 580         }
 581
 582         *type = rel_type;
 583         *code = rel_code;
 584         *info = rel_info;
 585         *msg = rel_msg;
 586
 587 out:
 588         rcu_read_unlock();
 589         return err;
 590 }
 591
 592 static int
 593 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 594            u8 type, u8 code, int offset, __be32 info)
 595 {
 596         __u32 rel_info = ntohl(info);
 597         const struct iphdr *eiph;
 598         struct sk_buff *skb2;
 599         int err, rel_msg = 0;
 600         u8 rel_type = type;
 601         u8 rel_code = code;
 602         struct rtable *rt;
 603         struct flowi4 fl4;
 604
 605         err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
 606                           &rel_msg, &rel_info, offset);
 607         if (err < 0)
 608                 return err;
 609
 610         if (rel_msg == 0)
 611                 return 0;
 612
 613         switch (rel_type) {
 614         case ICMPV6_DEST_UNREACH:
 615                 if (rel_code != ICMPV6_ADDR_UNREACH)
 616                         return 0;
 617                 rel_type = ICMP_DEST_UNREACH;
 618                 rel_code = ICMP_HOST_UNREACH;
 619                 break;
 620         case ICMPV6_PKT_TOOBIG:
 621                 if (rel_code != 0)
 622                         return 0;
 623                 rel_type = ICMP_DEST_UNREACH;
 624                 rel_code = ICMP_FRAG_NEEDED;
 625                 break;
 626         default:
 627                 return 0;
 628         }
 629
 630         if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
 631                 return 0;
 632
 633         skb2 = skb_clone(skb, GFP_ATOMIC);
 634         if (!skb2)
 635                 return 0;
 636
 637         skb_dst_drop(skb2);
 638
 639         skb_pull(skb2, offset);
 640         skb_reset_network_header(skb2);
 641         eiph = ip_hdr(skb2);
 642
 643         /* Try to guess incoming interface */
 644         rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, eiph->saddr,
 645                                    0, 0, 0, IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 646         if (IS_ERR(rt))
 647                 goto out;
 648
 649         skb2->dev = rt->dst.dev;
 650         ip_rt_put(rt);
 651
 652         /* route "incoming" packet */
 653         if (rt->rt_flags & RTCF_LOCAL) {
 654                 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 655                                            eiph->daddr, eiph->saddr, 0, 0,
 656                                            IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 657                 if (IS_ERR(rt) || rt->dst.dev->type != ARPHRD_TUNNEL6) {
 658                         if (!IS_ERR(rt))
 659                                 ip_rt_put(rt);
 660                         goto out;
 661                 }
 662                 skb_dst_set(skb2, &rt->dst);
 663         } else {
 664                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
 665                                    skb2->dev) ||
 666                     skb_dst(skb2)->dev->type != ARPHRD_TUNNEL6)
 667                         goto out;
 668         }
 669
 670         /* change mtu on this route */
 671         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
 672                 if (rel_info > dst_mtu(skb_dst(skb2)))
 673                         goto out;
 674
 675                 skb_dst_update_pmtu_no_confirm(skb2, rel_info);
 676         }
 677
 678         icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
 679
 680 out:
 681         kfree_skb(skb2);
 682         return 0;
 683 }
 684
 685 static int
 686 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 687            u8 type, u8 code, int offset, __be32 info)
 688 {
 689         __u32 rel_info = ntohl(info);
 690         int err, rel_msg = 0;
 691         u8 rel_type = type;
 692         u8 rel_code = code;
 693
 694         err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
 695                           &rel_msg, &rel_info, offset);
 696         if (err < 0)
 697                 return err;
 698
 699         if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
 700                 struct rt6_info *rt;
 701                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 702
 703                 if (!skb2)
 704                         return 0;
 705
 706                 skb_dst_drop(skb2);
 707                 skb_pull(skb2, offset);
 708                 skb_reset_network_header(skb2);
 709
 710                 /* Try to guess incoming interface */
 711                 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
 712                                 NULL, 0, skb2, 0);
 713
 714                 if (rt && rt->dst.dev)
 715                         skb2->dev = rt->dst.dev;
 716
 717                 icmpv6_send(skb2, rel_type, rel_code, rel_info);
 718
 719                 ip6_rt_put(rt);
 720
 721                 kfree_skb(skb2);
 722         }
 723
 724         return 0;
 725 }
 726
 727 static int
 728 mplsip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 729             u8 type, u8 code, int offset, __be32 info)
 730 {
 731         __u32 rel_info = ntohl(info);
 732         int err, rel_msg = 0;
 733         u8 rel_type = type;
 734         u8 rel_code = code;
 735
 736         err = ip6_tnl_err(skb, IPPROTO_MPLS, opt, &rel_type, &rel_code,
 737                           &rel_msg, &rel_info, offset);
 738         return err;
 739 }
 740
 741 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 742                                        const struct ipv6hdr *ipv6h,
 743                                        struct sk_buff *skb)
 744 {
 745         __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
 746
 747         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 748                 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
 749
 750         return IP6_ECN_decapsulate(ipv6h, skb);
 751 }
 752
 753 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 754                                        const struct ipv6hdr *ipv6h,
 755                                        struct sk_buff *skb)
 756 {
 757         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 758                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
 759
 760         return IP6_ECN_decapsulate(ipv6h, skb);
 761 }
 762
 763 static inline int mplsip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 764                                                const struct ipv6hdr *ipv6h,
 765                                                struct sk_buff *skb)
 766 {
 767         /* ECN is not supported in AF_MPLS */
 768         return 0;
 769 }
 770
 771 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
 772                              const struct in6_addr *laddr,
 773                              const struct in6_addr *raddr)
 774 {
 775         struct __ip6_tnl_parm *p = &t->parms;
 776         int ltype = ipv6_addr_type(laddr);
 777         int rtype = ipv6_addr_type(raddr);
 778         __u32 flags = 0;
 779
 780         if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
 781                 flags = IP6_TNL_F_CAP_PER_PACKET;
 782         } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 783                    rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 784                    !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
 785                    (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
 786                 if (ltype&IPV6_ADDR_UNICAST)
 787                         flags |= IP6_TNL_F_CAP_XMIT;
 788                 if (rtype&IPV6_ADDR_UNICAST)
 789                         flags |= IP6_TNL_F_CAP_RCV;
 790         }
 791         return flags;
 792 }
 793 EXPORT_SYMBOL(ip6_tnl_get_cap);
 794
 795 /* called with rcu_read_lock() */
 796 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
 797                                   const struct in6_addr *laddr,
 798                                   const struct in6_addr *raddr)
 799 {
 800         struct __ip6_tnl_parm *p = &t->parms;
 801         int ret = 0;
 802         struct net *net = t->net;
 803
 804         if ((p->flags & IP6_TNL_F_CAP_RCV) ||
 805             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
 806              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
 807                 struct net_device *ldev = NULL;
 808
 809                 if (p->link)
 810                         ldev = dev_get_by_index_rcu(net, p->link);
 811
 812                 if ((ipv6_addr_is_multicast(laddr) ||
 813                      likely(ipv6_chk_addr_and_flags(net, laddr, ldev, false,
 814                                                     0, IFA_F_TENTATIVE))) &&
 815                     ((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
 816                      likely(!ipv6_chk_addr_and_flags(net, raddr, ldev, true,
 817                                                      0, IFA_F_TENTATIVE))))
 818                         ret = 1;
 819         }
 820         return ret;
 821 }
 822 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
 823
 824 static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
 825                          const struct tnl_ptk_info *tpi,
 826                          struct metadata_dst *tun_dst,
 827                          int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 828                                                 const struct ipv6hdr *ipv6h,
 829                                                 struct sk_buff *skb),
 830                          bool log_ecn_err)
 831 {
 832         const struct ipv6hdr *ipv6h;
 833         int nh, err;
 834
 835         if ((!(tpi->flags & TUNNEL_CSUM) &&
 836              (tunnel->parms.i_flags & TUNNEL_CSUM)) ||
 837             ((tpi->flags & TUNNEL_CSUM) &&
 838              !(tunnel->parms.i_flags & TUNNEL_CSUM))) {
 839                 tunnel->dev->stats.rx_crc_errors++;
 840                 tunnel->dev->stats.rx_errors++;
 841                 goto drop;
 842         }
 843
 844         if (tunnel->parms.i_flags & TUNNEL_SEQ) {
 845                 if (!(tpi->flags & TUNNEL_SEQ) ||
 846                     (tunnel->i_seqno &&
 847                      (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
 848                         tunnel->dev->stats.rx_fifo_errors++;
 849                         tunnel->dev->stats.rx_errors++;
 850                         goto drop;
 851                 }
 852                 tunnel->i_seqno = ntohl(tpi->seq) + 1;
 853         }
 854
 855         skb->protocol = tpi->proto;
 856
 857         /* Warning: All skb pointers will be invalidated! */
 858         if (tunnel->dev->type == ARPHRD_ETHER) {
 859                 if (!pskb_may_pull(skb, ETH_HLEN)) {
 860                         tunnel->dev->stats.rx_length_errors++;
 861                         tunnel->dev->stats.rx_errors++;
 862                         goto drop;
 863                 }
 864
 865                 skb->protocol = eth_type_trans(skb, tunnel->dev);
 866                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 867         } else {
 868                 skb->dev = tunnel->dev;
 869         }
 870
 871         /* Save offset of outer header relative to skb->head,
 872          * because we are going to reset the network header to the inner header
 873          * and might change skb->head.
 874          */
 875         nh = skb_network_header(skb) - skb->head;
 876
 877         skb_reset_network_header(skb);
 878
 879         if (!pskb_inet_may_pull(skb)) {
 880                 DEV_STATS_INC(tunnel->dev, rx_length_errors);
 881                 DEV_STATS_INC(tunnel->dev, rx_errors);
 882                 goto drop;
 883         }
 884
 885         /* Get the outer header. */
 886         ipv6h = (struct ipv6hdr *)(skb->head + nh);
 887
 888         memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 889
 890         __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 891
 892         err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
 893         if (unlikely(err)) {
 894                 if (log_ecn_err)
 895                         net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
 896                                              &ipv6h->saddr,
 897                                              ipv6_get_dsfield(ipv6h));
 898                 if (err > 1) {
 899                         ++tunnel->dev->stats.rx_frame_errors;
 900                         ++tunnel->dev->stats.rx_errors;
 901                         goto drop;
 902                 }
 903         }
 904
 905         dev_sw_netstats_rx_add(tunnel->dev, skb->len);
 906
 907         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
 908
 909         if (tun_dst)
 910                 skb_dst_set(skb, (struct dst_entry *)tun_dst);
 911
 912         gro_cells_receive(&tunnel->gro_cells, skb);
 913         return 0;
 914
 915 drop:
 916         if (tun_dst)
 917                 dst_release((struct dst_entry *)tun_dst);
 918         kfree_skb(skb);
 919         return 0;
 920 }
 921
 922 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
 923                 const struct tnl_ptk_info *tpi,
 924                 struct metadata_dst *tun_dst,
 925                 bool log_ecn_err)
 926 {
 927         int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 928                                     const struct ipv6hdr *ipv6h,
 929                                     struct sk_buff *skb);
 930
 931         dscp_ecn_decapsulate = ip6ip6_dscp_ecn_decapsulate;
 932         if (tpi->proto == htons(ETH_P_IP))
 933                 dscp_ecn_decapsulate = ip4ip6_dscp_ecn_decapsulate;
 934
 935         return __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
 936                              log_ecn_err);
 937 }
 938 EXPORT_SYMBOL(ip6_tnl_rcv);
 939
 940 static const struct tnl_ptk_info tpi_v6 = {
 941         /* no tunnel info required for ipxip6. */
 942         .proto = htons(ETH_P_IPV6),
 943 };
 944
 945 static const struct tnl_ptk_info tpi_v4 = {
 946         /* no tunnel info required for ipxip6. */
 947         .proto = htons(ETH_P_IP),
 948 };
 949
 950 static const struct tnl_ptk_info tpi_mpls = {
 951         /* no tunnel info required for mplsip6. */
 952         .proto = htons(ETH_P_MPLS_UC),
 953 };
 954
 955 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
 956                       const struct tnl_ptk_info *tpi,
 957                       int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 958                                                   const struct ipv6hdr *ipv6h,
 959                                                   struct sk_buff *skb))
 960 {
 961         struct ip6_tnl *t;
 962         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 963         struct metadata_dst *tun_dst = NULL;
 964         int ret = -1;
 965
 966         rcu_read_lock();
 967         t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->saddr, &ipv6h->daddr);
 968
 969         if (t) {
 970                 u8 tproto = READ_ONCE(t->parms.proto);
 971
 972                 if (tproto != ipproto && tproto != 0)
 973                         goto drop;
 974                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 975                         goto drop;
 976                 ipv6h = ipv6_hdr(skb);
 977                 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
 978                         goto drop;
 979                 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
 980                         goto drop;
 981                 if (t->parms.collect_md) {
 982                         tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
 983                         if (!tun_dst)
 984                                 goto drop;
 985                 }
 986                 ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
 987                                     log_ecn_error);
 988         }
 989
 990         rcu_read_unlock();
 991
 992         return ret;
 993
 994 drop:
 995         rcu_read_unlock();
 996         kfree_skb(skb);
 997         return 0;
 998 }
 999
1000 static int ip4ip6_rcv(struct sk_buff *skb)
1001 {
1002         return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
1003                           ip4ip6_dscp_ecn_decapsulate);
1004 }
1005
1006 static int ip6ip6_rcv(struct sk_buff *skb)
1007 {
1008         return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
1009                           ip6ip6_dscp_ecn_decapsulate);
1010 }
1011
1012 static int mplsip6_rcv(struct sk_buff *skb)
1013 {
1014         return ipxip6_rcv(skb, IPPROTO_MPLS, &tpi_mpls,
1015                           mplsip6_dscp_ecn_decapsulate);
1016 }
1017
1018 struct ipv6_tel_txoption {
1019         struct ipv6_txoptions ops;
1020         __u8 dst_opt[8];
1021 };
1022
1023 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
1024 {
1025         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
1026
1027         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
1028         opt->dst_opt[3] = 1;
1029         opt->dst_opt[4] = encap_limit;
1030         opt->dst_opt[5] = IPV6_TLV_PADN;
1031         opt->dst_opt[6] = 1;
1032
1033         opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
1034         opt->ops.opt_nflen = 8;
1035 }
1036
1037 /**
1038  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
1039  *   @t: the outgoing tunnel device
1040  *   @hdr: IPv6 header from the incoming packet
1041  *
1042  * Description:
1043  *   Avoid trivial tunneling loop by checking that tunnel exit-point
1044  *   doesn't match source of incoming packet.
1045  *
1046  * Return:
1047  *   1 if conflict,
1048  *   0 else
1049  **/
1050
1051 static inline bool
1052 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
1053 {
1054         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
1055 }
1056
1057 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
1058                      const struct in6_addr *laddr,
1059                      const struct in6_addr *raddr)
1060 {
1061         struct __ip6_tnl_parm *p = &t->parms;
1062         int ret = 0;
1063         struct net *net = t->net;
1064
1065         if (t->parms.collect_md)
1066                 return 1;
1067
1068         if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
1069             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
1070              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
1071                 struct net_device *ldev = NULL;
1072
1073                 rcu_read_lock();
1074                 if (p->link)
1075                         ldev = dev_get_by_index_rcu(net, p->link);
1076
1077                 if (unlikely(!ipv6_chk_addr_and_flags(net, laddr, ldev, false,
1078                                                       0, IFA_F_TENTATIVE)))
1079                         pr_warn_ratelimited("%s xmit: Local address not yet configured!\n",
1080                                             p->name);
1081                 else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
1082                          !ipv6_addr_is_multicast(raddr) &&
1083                          unlikely(ipv6_chk_addr_and_flags(net, raddr, ldev,
1084                                                           true, 0, IFA_F_TENTATIVE)))
1085                         pr_warn_ratelimited("%s xmit: Routing loop! Remote address found on this node!\n",
1086                                             p->name);
1087                 else
1088                         ret = 1;
1089                 rcu_read_unlock();
1090         }
1091         return ret;
1092 }
1093 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1094
1095 /**
1096  * ip6_tnl_xmit - encapsulate packet and send
1097  *   @skb: the outgoing socket buffer
1098  *   @dev: the outgoing tunnel device
1099  *   @dsfield: dscp code for outer header
1100  *   @fl6: flow of tunneled packet
1101  *   @encap_limit: encapsulation limit
1102  *   @pmtu: Path MTU is stored if packet is too big
1103  *   @proto: next header value
1104  *
1105  * Description:
1106  *   Build new header and do some sanity checks on the packet before sending
1107  *   it.
1108  *
1109  * Return:
1110  *   0 on success
1111  *   -1 fail
1112  *   %-EMSGSIZE message too big. return mtu in this case.
1113  **/
1114
1115 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1116                  struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1117                  __u8 proto)
1118 {
1119         struct ip6_tnl *t = netdev_priv(dev);
1120         struct net *net = t->net;
1121         struct net_device_stats *stats = &t->dev->stats;
1122         struct ipv6hdr *ipv6h;
1123         struct ipv6_tel_txoption opt;
1124         struct dst_entry *dst = NULL, *ndst = NULL;
1125         struct net_device *tdev;
1126         int mtu;
1127         unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1128         unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1129         unsigned int max_headroom = psh_hlen;
1130         bool use_cache = false;
1131         u8 hop_limit;
1132         int err = -1;
1133
1134         if (t->parms.collect_md) {
1135                 hop_limit = skb_tunnel_info(skb)->key.ttl;
1136                 goto route_lookup;
1137         } else {
1138                 hop_limit = t->parms.hop_limit;
1139         }
1140
1141         /* NBMA tunnel */
1142         if (ipv6_addr_any(&t->parms.raddr)) {
1143                 if (skb->protocol == htons(ETH_P_IPV6)) {
1144                         struct in6_addr *addr6;
1145                         struct neighbour *neigh;
1146                         int addr_type;
1147
1148                         if (!skb_dst(skb))
1149                                 goto tx_err_link_failure;
1150
1151                         neigh = dst_neigh_lookup(skb_dst(skb),
1152                                                  &ipv6_hdr(skb)->daddr);
1153                         if (!neigh)
1154                                 goto tx_err_link_failure;
1155
1156                         addr6 = (struct in6_addr *)&neigh->primary_key;
1157                         addr_type = ipv6_addr_type(addr6);
1158
1159                         if (addr_type == IPV6_ADDR_ANY)
1160                                 addr6 = &ipv6_hdr(skb)->daddr;
1161
1162                         memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1163                         neigh_release(neigh);
1164                 }
1165         } else if (t->parms.proto != 0 && !(t->parms.flags &
1166                                             (IP6_TNL_F_USE_ORIG_TCLASS |
1167                                              IP6_TNL_F_USE_ORIG_FWMARK))) {
1168                 /* enable the cache only if neither the outer protocol nor the
1169                  * routing decision depends on the current inner header value
1170                  */
1171                 use_cache = true;
1172         }
1173
1174         if (use_cache)
1175                 dst = dst_cache_get(&t->dst_cache);
1176
1177         if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1178                 goto tx_err_link_failure;
1179
1180         if (!dst) {
1181 route_lookup:
1182                 /* add dsfield to flowlabel for route lookup */
1183                 fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1184
1185                 dst = ip6_route_output(net, NULL, fl6);
1186
1187                 if (dst->error)
1188                         goto tx_err_link_failure;
1189                 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1190                 if (IS_ERR(dst)) {
1191                         err = PTR_ERR(dst);
1192                         dst = NULL;
1193                         goto tx_err_link_failure;
1194                 }
1195                 if (t->parms.collect_md && ipv6_addr_any(&fl6->saddr) &&
1196                     ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1197                                        &fl6->daddr, 0, &fl6->saddr))
1198                         goto tx_err_link_failure;
1199                 ndst = dst;
1200         }
1201
1202         tdev = dst->dev;
1203
1204         if (tdev == dev) {
1205                 stats->collisions++;
1206                 net_warn_ratelimited("%s: Local routing loop detected!\n",
1207                                      t->parms.name);
1208                 goto tx_err_dst_release;
1209         }
1210         mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
1211         if (encap_limit >= 0) {
1212                 max_headroom += 8;
1213                 mtu -= 8;
1214         }
1215         mtu = max(mtu, skb->protocol == htons(ETH_P_IPV6) ?
1216                        IPV6_MIN_MTU : IPV4_MIN_MTU);
1217
1218         skb_dst_update_pmtu_no_confirm(skb, mtu);
1219         if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
1220                 *pmtu = mtu;
1221                 err = -EMSGSIZE;
1222                 goto tx_err_dst_release;
1223         }
1224
1225         if (t->err_count > 0) {
1226                 if (time_before(jiffies,
1227                                 t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1228                         t->err_count--;
1229
1230                         dst_link_failure(skb);
1231                 } else {
1232                         t->err_count = 0;
1233                 }
1234         }
1235
1236         skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1237
1238         /*
1239          * Okay, now see if we can stuff it in the buffer as-is.
1240          */
1241         max_headroom += LL_RESERVED_SPACE(tdev);
1242
1243         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1244             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1245                 struct sk_buff *new_skb;
1246
1247                 new_skb = skb_realloc_headroom(skb, max_headroom);
1248                 if (!new_skb)
1249                         goto tx_err_dst_release;
1250
1251                 if (skb->sk)
1252                         skb_set_owner_w(new_skb, skb->sk);
1253                 consume_skb(skb);
1254                 skb = new_skb;
1255         }
1256
1257         if (t->parms.collect_md) {
1258                 if (t->encap.type != TUNNEL_ENCAP_NONE)
1259                         goto tx_err_dst_release;
1260         } else {
1261                 if (use_cache && ndst)
1262                         dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1263         }
1264         skb_dst_set(skb, dst);
1265
1266         if (hop_limit == 0) {
1267                 if (skb->protocol == htons(ETH_P_IP))
1268                         hop_limit = ip_hdr(skb)->ttl;
1269                 else if (skb->protocol == htons(ETH_P_IPV6))
1270                         hop_limit = ipv6_hdr(skb)->hop_limit;
1271                 else
1272                         hop_limit = ip6_dst_hoplimit(dst);
1273         }
1274
1275         /* Calculate max headroom for all the headers and adjust
1276          * needed_headroom if necessary.
1277          */
1278         max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1279                         + dst->header_len + t->hlen;
1280         if (max_headroom > READ_ONCE(dev->needed_headroom))
1281                 WRITE_ONCE(dev->needed_headroom, max_headroom);
1282
1283         err = ip6_tnl_encap(skb, t, &proto, fl6);
1284         if (err)
1285                 return err;
1286
1287         if (encap_limit >= 0) {
1288                 init_tel_txopt(&opt, encap_limit);
1289                 ipv6_push_frag_opts(skb, &opt.ops, &proto);
1290         }
1291
1292         skb_push(skb, sizeof(struct ipv6hdr));
1293         skb_reset_network_header(skb);
1294         ipv6h = ipv6_hdr(skb);
1295         ip6_flow_hdr(ipv6h, dsfield,
1296                      ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1297         ipv6h->hop_limit = hop_limit;
1298         ipv6h->nexthdr = proto;
1299         ipv6h->saddr = fl6->saddr;
1300         ipv6h->daddr = fl6->daddr;
1301         ip6tunnel_xmit(NULL, skb, dev);
1302         return 0;
1303 tx_err_link_failure:
1304         stats->tx_carrier_errors++;
1305         dst_link_failure(skb);
1306 tx_err_dst_release:
1307         dst_release(dst);
1308         return err;
1309 }
1310 EXPORT_SYMBOL(ip6_tnl_xmit);
1311
1312 static inline int
1313 ipxip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev,
1314                 u8 protocol)
1315 {
1316         struct ip6_tnl *t = netdev_priv(dev);
1317         struct ipv6hdr *ipv6h;
1318         const struct iphdr  *iph;
1319         int encap_limit = -1;
1320         __u16 offset;
1321         struct flowi6 fl6;
1322         __u8 dsfield, orig_dsfield;
1323         __u32 mtu;
1324         u8 tproto;
1325         int err;
1326
1327         tproto = READ_ONCE(t->parms.proto);
1328         if (tproto != protocol && tproto != 0)
1329                 return -1;
1330
1331         if (t->parms.collect_md) {
1332                 struct ip_tunnel_info *tun_info;
1333                 const struct ip_tunnel_key *key;
1334
1335                 tun_info = skb_tunnel_info(skb);
1336                 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1337                              ip_tunnel_info_af(tun_info) != AF_INET6))
1338                         return -1;
1339                 key = &tun_info->key;
1340                 memset(&fl6, 0, sizeof(fl6));
1341                 fl6.flowi6_proto = protocol;
1342                 fl6.saddr = key->u.ipv6.src;
1343                 fl6.daddr = key->u.ipv6.dst;
1344                 fl6.flowlabel = key->label;
1345                 dsfield =  key->tos;
1346                 switch (protocol) {
1347                 case IPPROTO_IPIP:
1348                         iph = ip_hdr(skb);
1349                         orig_dsfield = ipv4_get_dsfield(iph);
1350                         break;
1351                 case IPPROTO_IPV6:
1352                         ipv6h = ipv6_hdr(skb);
1353                         orig_dsfield = ipv6_get_dsfield(ipv6h);
1354                         break;
1355                 default:
1356                         orig_dsfield = dsfield;
1357                         break;
1358                 }
1359         } else {
1360                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1361                         encap_limit = t->parms.encap_limit;
1362                 if (protocol == IPPROTO_IPV6) {
1363                         offset = ip6_tnl_parse_tlv_enc_lim(skb,
1364                                                 skb_network_header(skb));
1365                         /* ip6_tnl_parse_tlv_enc_lim() might have
1366                          * reallocated skb->head
1367                          */
1368                         if (offset > 0) {
1369                                 struct ipv6_tlv_tnl_enc_lim *tel;
1370
1371                                 tel = (void *)&skb_network_header(skb)[offset];
1372                                 if (tel->encap_limit == 0) {
1373                                         icmpv6_ndo_send(skb, ICMPV6_PARAMPROB,
1374                                                         ICMPV6_HDR_FIELD, offset + 2);
1375                                         return -1;
1376                                 }
1377                                 encap_limit = tel->encap_limit - 1;
1378                         }
1379                 }
1380
1381                 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1382                 fl6.flowi6_proto = protocol;
1383
1384                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1385                         fl6.flowi6_mark = skb->mark;
1386                 else
1387                         fl6.flowi6_mark = t->parms.fwmark;
1388                 switch (protocol) {
1389                 case IPPROTO_IPIP:
1390                         iph = ip_hdr(skb);
1391                         orig_dsfield = ipv4_get_dsfield(iph);
1392                         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1393                                 dsfield = orig_dsfield;
1394                         else
1395                                 dsfield = ip6_tclass(t->parms.flowinfo);
1396                         break;
1397                 case IPPROTO_IPV6:
1398                         ipv6h = ipv6_hdr(skb);
1399                         orig_dsfield = ipv6_get_dsfield(ipv6h);
1400                         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1401                                 dsfield = orig_dsfield;
1402                         else
1403                                 dsfield = ip6_tclass(t->parms.flowinfo);
1404                         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1405                                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
1406                         break;
1407                 default:
1408                         orig_dsfield = dsfield = ip6_tclass(t->parms.flowinfo);
1409                         break;
1410                 }
1411         }
1412
1413         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1414         dsfield = INET_ECN_encapsulate(dsfield, orig_dsfield);
1415
1416         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1417                 return -1;
1418
1419         skb_set_inner_ipproto(skb, protocol);
1420
1421         err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1422                            protocol);
1423         if (err != 0) {
1424                 /* XXX: send ICMP error even if DF is not set. */
1425                 if (err == -EMSGSIZE)
1426                         switch (protocol) {
1427                         case IPPROTO_IPIP:
1428                                 icmp_ndo_send(skb, ICMP_DEST_UNREACH,
1429                                               ICMP_FRAG_NEEDED, htonl(mtu));
1430                                 break;
1431                         case IPPROTO_IPV6:
1432                                 icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1433                                 break;
1434                         default:
1435                                 break;
1436                         }
1437                 return -1;
1438         }
1439
1440         return 0;
1441 }
1442
1443 static netdev_tx_t
1444 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1445 {
1446         struct ip6_tnl *t = netdev_priv(dev);
1447         struct net_device_stats *stats = &t->dev->stats;
1448         u8 ipproto;
1449         int ret;
1450
1451         if (!pskb_inet_may_pull(skb))
1452                 goto tx_err;
1453
1454         switch (skb->protocol) {
1455         case htons(ETH_P_IP):
1456                 ipproto = IPPROTO_IPIP;
1457                 break;
1458         case htons(ETH_P_IPV6):
1459                 if (ip6_tnl_addr_conflict(t, ipv6_hdr(skb)))
1460                         goto tx_err;
1461                 ipproto = IPPROTO_IPV6;
1462                 break;
1463         case htons(ETH_P_MPLS_UC):
1464                 ipproto = IPPROTO_MPLS;
1465                 break;
1466         default:
1467                 goto tx_err;
1468         }
1469
1470         ret = ipxip6_tnl_xmit(skb, dev, ipproto);
1471         if (ret < 0)
1472                 goto tx_err;
1473
1474         return NETDEV_TX_OK;
1475
1476 tx_err:
1477         stats->tx_errors++;
1478         stats->tx_dropped++;
1479         kfree_skb(skb);
1480         return NETDEV_TX_OK;
1481 }
1482
1483 static void ip6_tnl_link_config(struct ip6_tnl *t)
1484 {
1485         struct net_device *dev = t->dev;
1486         struct net_device *tdev = NULL;
1487         struct __ip6_tnl_parm *p = &t->parms;
1488         struct flowi6 *fl6 = &t->fl.u.ip6;
1489         int t_hlen;
1490         int mtu;
1491
1492         memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1493         memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1494
1495         /* Set up flowi template */
1496         fl6->saddr = p->laddr;
1497         fl6->daddr = p->raddr;
1498         fl6->flowi6_oif = p->link;
1499         fl6->flowlabel = 0;
1500
1501         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1502                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1503         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1504                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1505
1506         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1507         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1508
1509         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1510                 dev->flags |= IFF_POINTOPOINT;
1511         else
1512                 dev->flags &= ~IFF_POINTOPOINT;
1513
1514         t->tun_hlen = 0;
1515         t->hlen = t->encap_hlen + t->tun_hlen;
1516         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1517
1518         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1519                 int strict = (ipv6_addr_type(&p->raddr) &
1520                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1521
1522                 struct rt6_info *rt = rt6_lookup(t->net,
1523                                                  &p->raddr, &p->laddr,
1524                                                  p->link, NULL, strict);
1525                 if (rt) {
1526                         tdev = rt->dst.dev;
1527                         ip6_rt_put(rt);
1528                 }
1529
1530                 if (!tdev && p->link)
1531                         tdev = __dev_get_by_index(t->net, p->link);
1532
1533                 if (tdev) {
1534                         dev->hard_header_len = tdev->hard_header_len + t_hlen;
1535                         mtu = min_t(unsigned int, tdev->mtu, IP6_MAX_MTU);
1536
1537                         mtu = mtu - t_hlen;
1538                         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1539                                 mtu -= 8;
1540
1541                         if (mtu < IPV6_MIN_MTU)
1542                                 mtu = IPV6_MIN_MTU;
1543                         WRITE_ONCE(dev->mtu, mtu);
1544                 }
1545         }
1546 }
1547
1548 /**
1549  * ip6_tnl_change - update the tunnel parameters
1550  *   @t: tunnel to be changed
1551  *   @p: tunnel configuration parameters
1552  *
1553  * Description:
1554  *   ip6_tnl_change() updates the tunnel parameters
1555  **/
1556
1557 static int
1558 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1559 {
1560         t->parms.laddr = p->laddr;
1561         t->parms.raddr = p->raddr;
1562         t->parms.flags = p->flags;
1563         t->parms.hop_limit = p->hop_limit;
1564         t->parms.encap_limit = p->encap_limit;
1565         t->parms.flowinfo = p->flowinfo;
1566         t->parms.link = p->link;
1567         t->parms.proto = p->proto;
1568         t->parms.fwmark = p->fwmark;
1569         dst_cache_reset(&t->dst_cache);
1570         ip6_tnl_link_config(t);
1571         return 0;
1572 }
1573
1574 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1575 {
1576         struct net *net = t->net;
1577         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1578         int err;
1579
1580         ip6_tnl_unlink(ip6n, t);
1581         synchronize_net();
1582         err = ip6_tnl_change(t, p);
1583         ip6_tnl_link(ip6n, t);
1584         netdev_state_change(t->dev);
1585         return err;
1586 }
1587
1588 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1589 {
1590         /* for default tnl0 device allow to change only the proto */
1591         t->parms.proto = p->proto;
1592         netdev_state_change(t->dev);
1593         return 0;
1594 }
1595
1596 static void
1597 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1598 {
1599         p->laddr = u->laddr;
1600         p->raddr = u->raddr;
1601         p->flags = u->flags;
1602         p->hop_limit = u->hop_limit;
1603         p->encap_limit = u->encap_limit;
1604         p->flowinfo = u->flowinfo;
1605         p->link = u->link;
1606         p->proto = u->proto;
1607         memcpy(p->name, u->name, sizeof(u->name));
1608 }
1609
1610 static void
1611 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1612 {
1613         u->laddr = p->laddr;
1614         u->raddr = p->raddr;
1615         u->flags = p->flags;
1616         u->hop_limit = p->hop_limit;
1617         u->encap_limit = p->encap_limit;
1618         u->flowinfo = p->flowinfo;
1619         u->link = p->link;
1620         u->proto = p->proto;
1621         memcpy(u->name, p->name, sizeof(u->name));
1622 }
1623
1624 /**
1625  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1626  *   @dev: virtual device associated with tunnel
1627  *   @ifr: parameters passed from userspace
1628  *   @cmd: command to be performed
1629  *
1630  * Description:
1631  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1632  *   from userspace.
1633  *
1634  *   The possible commands are the following:
1635  *     %SIOCGETTUNNEL: get tunnel parameters for device
1636  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1637  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1638  *     %SIOCDELTUNNEL: delete tunnel
1639  *
1640  *   The fallback device "ip6tnl0", created during module
1641  *   initialization, can be used for creating other tunnel devices.
1642  *
1643  * Return:
1644  *   0 on success,
1645  *   %-EFAULT if unable to copy data to or from userspace,
1646  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1647  *   %-EINVAL if passed tunnel parameters are invalid,
1648  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1649  *   %-ENODEV if attempting to change or delete a nonexisting device
1650  **/
1651
1652 static int
1653 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1654 {
1655         int err = 0;
1656         struct ip6_tnl_parm p;
1657         struct __ip6_tnl_parm p1;
1658         struct ip6_tnl *t = netdev_priv(dev);
1659         struct net *net = t->net;
1660         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1661
1662         memset(&p1, 0, sizeof(p1));
1663
1664         switch (cmd) {
1665         case SIOCGETTUNNEL:
1666                 if (dev == ip6n->fb_tnl_dev) {
1667                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1668                                 err = -EFAULT;
1669                                 break;
1670                         }
1671                         ip6_tnl_parm_from_user(&p1, &p);
1672                         t = ip6_tnl_locate(net, &p1, 0);
1673                         if (IS_ERR(t))
1674                                 t = netdev_priv(dev);
1675                 } else {
1676                         memset(&p, 0, sizeof(p));
1677                 }
1678                 ip6_tnl_parm_to_user(&p, &t->parms);
1679                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1680                         err = -EFAULT;
1681                 }
1682                 break;
1683         case SIOCADDTUNNEL:
1684         case SIOCCHGTUNNEL:
1685                 err = -EPERM;
1686                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1687                         break;
1688                 err = -EFAULT;
1689                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1690                         break;
1691                 err = -EINVAL;
1692                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1693                     p.proto != 0)
1694                         break;
1695                 ip6_tnl_parm_from_user(&p1, &p);
1696                 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1697                 if (cmd == SIOCCHGTUNNEL) {
1698                         if (!IS_ERR(t)) {
1699                                 if (t->dev != dev) {
1700                                         err = -EEXIST;
1701                                         break;
1702                                 }
1703                         } else
1704                                 t = netdev_priv(dev);
1705                         if (dev == ip6n->fb_tnl_dev)
1706                                 err = ip6_tnl0_update(t, &p1);
1707                         else
1708                                 err = ip6_tnl_update(t, &p1);
1709                 }
1710                 if (!IS_ERR(t)) {
1711                         err = 0;
1712                         ip6_tnl_parm_to_user(&p, &t->parms);
1713                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1714                                 err = -EFAULT;
1715
1716                 } else {
1717                         err = PTR_ERR(t);
1718                 }
1719                 break;
1720         case SIOCDELTUNNEL:
1721                 err = -EPERM;
1722                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1723                         break;
1724
1725                 if (dev == ip6n->fb_tnl_dev) {
1726                         err = -EFAULT;
1727                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1728                                 break;
1729                         err = -ENOENT;
1730                         ip6_tnl_parm_from_user(&p1, &p);
1731                         t = ip6_tnl_locate(net, &p1, 0);
1732                         if (IS_ERR(t))
1733                                 break;
1734                         err = -EPERM;
1735                         if (t->dev == ip6n->fb_tnl_dev)
1736                                 break;
1737                         dev = t->dev;
1738                 }
1739                 err = 0;
1740                 unregister_netdevice(dev);
1741                 break;
1742         default:
1743                 err = -EINVAL;
1744         }
1745         return err;
1746 }
1747
1748 /**
1749  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1750  *   @dev: virtual device associated with tunnel
1751  *   @new_mtu: the new mtu
1752  *
1753  * Return:
1754  *   0 on success,
1755  *   %-EINVAL if mtu too small
1756  **/
1757
1758 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1759 {
1760         struct ip6_tnl *tnl = netdev_priv(dev);
1761
1762         if (tnl->parms.proto == IPPROTO_IPV6) {
1763                 if (new_mtu < IPV6_MIN_MTU)
1764                         return -EINVAL;
1765         } else {
1766                 if (new_mtu < ETH_MIN_MTU)
1767                         return -EINVAL;
1768         }
1769         if (tnl->parms.proto == IPPROTO_IPV6 || tnl->parms.proto == 0) {
1770                 if (new_mtu > IP6_MAX_MTU - dev->hard_header_len)
1771                         return -EINVAL;
1772         } else {
1773                 if (new_mtu > IP_MAX_MTU - dev->hard_header_len)
1774                         return -EINVAL;
1775         }
1776         dev->mtu = new_mtu;
1777         return 0;
1778 }
1779 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1780
1781 int ip6_tnl_get_iflink(const struct net_device *dev)
1782 {
1783         struct ip6_tnl *t = netdev_priv(dev);
1784
1785         return t->parms.link;
1786 }
1787 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1788
1789 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1790                           unsigned int num)
1791 {
1792         if (num >= MAX_IPTUN_ENCAP_OPS)
1793                 return -ERANGE;
1794
1795         return !cmpxchg((const struct ip6_tnl_encap_ops **)
1796                         &ip6tun_encaps[num],
1797                         NULL, ops) ? 0 : -1;
1798 }
1799 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1800
1801 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1802                           unsigned int num)
1803 {
1804         int ret;
1805
1806         if (num >= MAX_IPTUN_ENCAP_OPS)
1807                 return -ERANGE;
1808
1809         ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1810                        &ip6tun_encaps[num],
1811                        ops, NULL) == ops) ? 0 : -1;
1812
1813         synchronize_net();
1814
1815         return ret;
1816 }
1817 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1818
1819 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1820                         struct ip_tunnel_encap *ipencap)
1821 {
1822         int hlen;
1823
1824         memset(&t->encap, 0, sizeof(t->encap));
1825
1826         hlen = ip6_encap_hlen(ipencap);
1827         if (hlen < 0)
1828                 return hlen;
1829
1830         t->encap.type = ipencap->type;
1831         t->encap.sport = ipencap->sport;
1832         t->encap.dport = ipencap->dport;
1833         t->encap.flags = ipencap->flags;
1834
1835         t->encap_hlen = hlen;
1836         t->hlen = t->encap_hlen + t->tun_hlen;
1837
1838         return 0;
1839 }
1840 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1841
1842 static const struct net_device_ops ip6_tnl_netdev_ops = {
1843         .ndo_init       = ip6_tnl_dev_init,
1844         .ndo_uninit     = ip6_tnl_dev_uninit,
1845         .ndo_start_xmit = ip6_tnl_start_xmit,
1846         .ndo_do_ioctl   = ip6_tnl_ioctl,
1847         .ndo_change_mtu = ip6_tnl_change_mtu,
1848         .ndo_get_stats  = ip6_get_stats,
1849         .ndo_get_iflink = ip6_tnl_get_iflink,
1850 };
1851
1852 #define IPXIPX_FEATURES (NETIF_F_SG |           \
1853                          NETIF_F_FRAGLIST |     \
1854                          NETIF_F_HIGHDMA |      \
1855                          NETIF_F_GSO_SOFTWARE | \
1856                          NETIF_F_HW_CSUM)
1857
1858 /**
1859  * ip6_tnl_dev_setup - setup virtual tunnel device
1860  *   @dev: virtual device associated with tunnel
1861  *
1862  * Description:
1863  *   Initialize function pointers and device parameters
1864  **/
1865
1866 static void ip6_tnl_dev_setup(struct net_device *dev)
1867 {
1868         dev->netdev_ops = &ip6_tnl_netdev_ops;
1869         dev->header_ops = &ip_tunnel_header_ops;
1870         dev->needs_free_netdev = true;
1871         dev->priv_destructor = ip6_dev_free;
1872
1873         dev->type = ARPHRD_TUNNEL6;
1874         dev->flags |= IFF_NOARP;
1875         dev->addr_len = sizeof(struct in6_addr);
1876         dev->features |= NETIF_F_LLTX;
1877         netif_keep_dst(dev);
1878
1879         dev->features           |= IPXIPX_FEATURES;
1880         dev->hw_features        |= IPXIPX_FEATURES;
1881
1882         /* This perm addr will be used as interface identifier by IPv6 */
1883         dev->addr_assign_type = NET_ADDR_RANDOM;
1884         eth_random_addr(dev->perm_addr);
1885 }
1886
1887
1888 /**
1889  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1890  *   @dev: virtual device associated with tunnel
1891  **/
1892
1893 static inline int
1894 ip6_tnl_dev_init_gen(struct net_device *dev)
1895 {
1896         struct ip6_tnl *t = netdev_priv(dev);
1897         int ret;
1898         int t_hlen;
1899
1900         t->dev = dev;
1901         t->net = dev_net(dev);
1902         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1903         if (!dev->tstats)
1904                 return -ENOMEM;
1905
1906         ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1907         if (ret)
1908                 goto free_stats;
1909
1910         ret = gro_cells_init(&t->gro_cells, dev);
1911         if (ret)
1912                 goto destroy_dst;
1913
1914         t->tun_hlen = 0;
1915         t->hlen = t->encap_hlen + t->tun_hlen;
1916         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1917
1918         dev->type = ARPHRD_TUNNEL6;
1919         dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1920         dev->mtu = ETH_DATA_LEN - t_hlen;
1921         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1922                 dev->mtu -= 8;
1923         dev->min_mtu = ETH_MIN_MTU;
1924         dev->max_mtu = IP6_MAX_MTU - dev->hard_header_len;
1925
1926         dev_hold(dev);
1927         return 0;
1928
1929 destroy_dst:
1930         dst_cache_destroy(&t->dst_cache);
1931 free_stats:
1932         free_percpu(dev->tstats);
1933         dev->tstats = NULL;
1934
1935         return ret;
1936 }
1937
1938 /**
1939  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1940  *   @dev: virtual device associated with tunnel
1941  **/
1942
1943 static int ip6_tnl_dev_init(struct net_device *dev)
1944 {
1945         struct ip6_tnl *t = netdev_priv(dev);
1946         int err = ip6_tnl_dev_init_gen(dev);
1947
1948         if (err)
1949                 return err;
1950         ip6_tnl_link_config(t);
1951         if (t->parms.collect_md)
1952                 netif_keep_dst(dev);
1953         return 0;
1954 }
1955
1956 /**
1957  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1958  *   @dev: fallback device
1959  *
1960  * Return: 0
1961  **/
1962
1963 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1964 {
1965         struct ip6_tnl *t = netdev_priv(dev);
1966         struct net *net = dev_net(dev);
1967         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1968
1969         t->parms.proto = IPPROTO_IPV6;
1970
1971         rcu_assign_pointer(ip6n->tnls_wc[0], t);
1972         return 0;
1973 }
1974
1975 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[],
1976                             struct netlink_ext_ack *extack)
1977 {
1978         u8 proto;
1979
1980         if (!data || !data[IFLA_IPTUN_PROTO])
1981                 return 0;
1982
1983         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1984         if (proto != IPPROTO_IPV6 &&
1985             proto != IPPROTO_IPIP &&
1986             proto != 0)
1987                 return -EINVAL;
1988
1989         return 0;
1990 }
1991
1992 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1993                                   struct __ip6_tnl_parm *parms)
1994 {
1995         memset(parms, 0, sizeof(*parms));
1996
1997         if (!data)
1998                 return;
1999
2000         if (data[IFLA_IPTUN_LINK])
2001                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
2002
2003         if (data[IFLA_IPTUN_LOCAL])
2004                 parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
2005
2006         if (data[IFLA_IPTUN_REMOTE])
2007                 parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
2008
2009         if (data[IFLA_IPTUN_TTL])
2010                 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
2011
2012         if (data[IFLA_IPTUN_ENCAP_LIMIT])
2013                 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
2014
2015         if (data[IFLA_IPTUN_FLOWINFO])
2016                 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
2017
2018         if (data[IFLA_IPTUN_FLAGS])
2019                 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
2020
2021         if (data[IFLA_IPTUN_PROTO])
2022                 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
2023
2024         if (data[IFLA_IPTUN_COLLECT_METADATA])
2025                 parms->collect_md = true;
2026
2027         if (data[IFLA_IPTUN_FWMARK])
2028                 parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
2029 }
2030
2031 static bool ip6_tnl_netlink_encap_parms(struct nlattr *data[],
2032                                         struct ip_tunnel_encap *ipencap)
2033 {
2034         bool ret = false;
2035
2036         memset(ipencap, 0, sizeof(*ipencap));
2037
2038         if (!data)
2039                 return ret;
2040
2041         if (data[IFLA_IPTUN_ENCAP_TYPE]) {
2042                 ret = true;
2043                 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
2044         }
2045
2046         if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
2047                 ret = true;
2048                 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
2049         }
2050
2051         if (data[IFLA_IPTUN_ENCAP_SPORT]) {
2052                 ret = true;
2053                 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
2054         }
2055
2056         if (data[IFLA_IPTUN_ENCAP_DPORT]) {
2057                 ret = true;
2058                 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
2059         }
2060
2061         return ret;
2062 }
2063
2064 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
2065                            struct nlattr *tb[], struct nlattr *data[],
2066                            struct netlink_ext_ack *extack)
2067 {
2068         struct net *net = dev_net(dev);
2069         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2070         struct ip_tunnel_encap ipencap;
2071         struct ip6_tnl *nt, *t;
2072         int err;
2073
2074         nt = netdev_priv(dev);
2075
2076         if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2077                 err = ip6_tnl_encap_setup(nt, &ipencap);
2078                 if (err < 0)
2079                         return err;
2080         }
2081
2082         ip6_tnl_netlink_parms(data, &nt->parms);
2083
2084         if (nt->parms.collect_md) {
2085                 if (rtnl_dereference(ip6n->collect_md_tun))
2086                         return -EEXIST;
2087         } else {
2088                 t = ip6_tnl_locate(net, &nt->parms, 0);
2089                 if (!IS_ERR(t))
2090                         return -EEXIST;
2091         }
2092
2093         err = ip6_tnl_create2(dev);
2094         if (!err && tb[IFLA_MTU])
2095                 ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
2096
2097         return err;
2098 }
2099
2100 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
2101                               struct nlattr *data[],
2102                               struct netlink_ext_ack *extack)
2103 {
2104         struct ip6_tnl *t = netdev_priv(dev);
2105         struct __ip6_tnl_parm p;
2106         struct net *net = t->net;
2107         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2108         struct ip_tunnel_encap ipencap;
2109
2110         if (dev == ip6n->fb_tnl_dev)
2111                 return -EINVAL;
2112
2113         if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2114                 int err = ip6_tnl_encap_setup(t, &ipencap);
2115
2116                 if (err < 0)
2117                         return err;
2118         }
2119         ip6_tnl_netlink_parms(data, &p);
2120         if (p.collect_md)
2121                 return -EINVAL;
2122
2123         t = ip6_tnl_locate(net, &p, 0);
2124         if (!IS_ERR(t)) {
2125                 if (t->dev != dev)
2126                         return -EEXIST;
2127         } else
2128                 t = netdev_priv(dev);
2129
2130         return ip6_tnl_update(t, &p);
2131 }
2132
2133 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2134 {
2135         struct net *net = dev_net(dev);
2136         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2137
2138         if (dev != ip6n->fb_tnl_dev)
2139                 unregister_netdevice_queue(dev, head);
2140 }
2141
2142 static size_t ip6_tnl_get_size(const struct net_device *dev)
2143 {
2144         return
2145                 /* IFLA_IPTUN_LINK */
2146                 nla_total_size(4) +
2147                 /* IFLA_IPTUN_LOCAL */
2148                 nla_total_size(sizeof(struct in6_addr)) +
2149                 /* IFLA_IPTUN_REMOTE */
2150                 nla_total_size(sizeof(struct in6_addr)) +
2151                 /* IFLA_IPTUN_TTL */
2152                 nla_total_size(1) +
2153                 /* IFLA_IPTUN_ENCAP_LIMIT */
2154                 nla_total_size(1) +
2155                 /* IFLA_IPTUN_FLOWINFO */
2156                 nla_total_size(4) +
2157                 /* IFLA_IPTUN_FLAGS */
2158                 nla_total_size(4) +
2159                 /* IFLA_IPTUN_PROTO */
2160                 nla_total_size(1) +
2161                 /* IFLA_IPTUN_ENCAP_TYPE */
2162                 nla_total_size(2) +
2163                 /* IFLA_IPTUN_ENCAP_FLAGS */
2164                 nla_total_size(2) +
2165                 /* IFLA_IPTUN_ENCAP_SPORT */
2166                 nla_total_size(2) +
2167                 /* IFLA_IPTUN_ENCAP_DPORT */
2168                 nla_total_size(2) +
2169                 /* IFLA_IPTUN_COLLECT_METADATA */
2170                 nla_total_size(0) +
2171                 /* IFLA_IPTUN_FWMARK */
2172                 nla_total_size(4) +
2173                 0;
2174 }
2175
2176 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2177 {
2178         struct ip6_tnl *tunnel = netdev_priv(dev);
2179         struct __ip6_tnl_parm *parm = &tunnel->parms;
2180
2181         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2182             nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2183             nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2184             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2185             nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2186             nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2187             nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2188             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
2189             nla_put_u32(skb, IFLA_IPTUN_FWMARK, parm->fwmark))
2190                 goto nla_put_failure;
2191
2192         if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2193             nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2194             nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2195             nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2196                 goto nla_put_failure;
2197
2198         if (parm->collect_md)
2199                 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2200                         goto nla_put_failure;
2201
2202         return 0;
2203
2204 nla_put_failure:
2205         return -EMSGSIZE;
2206 }
2207
2208 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2209 {
2210         struct ip6_tnl *tunnel = netdev_priv(dev);
2211
2212         return tunnel->net;
2213 }
2214 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2215
2216 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2217         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
2218         [IFLA_IPTUN_LOCAL]              = { .len = sizeof(struct in6_addr) },
2219         [IFLA_IPTUN_REMOTE]             = { .len = sizeof(struct in6_addr) },
2220         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
2221         [IFLA_IPTUN_ENCAP_LIMIT]        = { .type = NLA_U8 },
2222         [IFLA_IPTUN_FLOWINFO]           = { .type = NLA_U32 },
2223         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U32 },
2224         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
2225         [IFLA_IPTUN_ENCAP_TYPE]         = { .type = NLA_U16 },
2226         [IFLA_IPTUN_ENCAP_FLAGS]        = { .type = NLA_U16 },
2227         [IFLA_IPTUN_ENCAP_SPORT]        = { .type = NLA_U16 },
2228         [IFLA_IPTUN_ENCAP_DPORT]        = { .type = NLA_U16 },
2229         [IFLA_IPTUN_COLLECT_METADATA]   = { .type = NLA_FLAG },
2230         [IFLA_IPTUN_FWMARK]             = { .type = NLA_U32 },
2231 };
2232
2233 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2234         .kind           = "ip6tnl",
2235         .maxtype        = IFLA_IPTUN_MAX,
2236         .policy         = ip6_tnl_policy,
2237         .priv_size      = sizeof(struct ip6_tnl),
2238         .setup          = ip6_tnl_dev_setup,
2239         .validate       = ip6_tnl_validate,
2240         .newlink        = ip6_tnl_newlink,
2241         .changelink     = ip6_tnl_changelink,
2242         .dellink        = ip6_tnl_dellink,
2243         .get_size       = ip6_tnl_get_size,
2244         .fill_info      = ip6_tnl_fill_info,
2245         .get_link_net   = ip6_tnl_get_link_net,
2246 };
2247
2248 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2249         .handler        = ip4ip6_rcv,
2250         .err_handler    = ip4ip6_err,
2251         .priority       =       1,
2252 };
2253
2254 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2255         .handler        = ip6ip6_rcv,
2256         .err_handler    = ip6ip6_err,
2257         .priority       =       1,
2258 };
2259
2260 static struct xfrm6_tunnel mplsip6_handler __read_mostly = {
2261         .handler        = mplsip6_rcv,
2262         .err_handler    = mplsip6_err,
2263         .priority       =       1,
2264 };
2265
2266 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net, struct list_head *list)
2267 {
2268         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2269         struct net_device *dev, *aux;
2270         int h;
2271         struct ip6_tnl *t;
2272
2273         for_each_netdev_safe(net, dev, aux)
2274                 if (dev->rtnl_link_ops == &ip6_link_ops)
2275                         unregister_netdevice_queue(dev, list);
2276
2277         for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2278                 t = rtnl_dereference(ip6n->tnls_r_l[h]);
2279                 while (t) {
2280                         /* If dev is in the same netns, it has already
2281                          * been added to the list by the previous loop.
2282                          */
2283                         if (!net_eq(dev_net(t->dev), net))
2284                                 unregister_netdevice_queue(t->dev, list);
2285                         t = rtnl_dereference(t->next);
2286                 }
2287         }
2288
2289         t = rtnl_dereference(ip6n->tnls_wc[0]);
2290         while (t) {
2291                 /* If dev is in the same netns, it has already
2292                  * been added to the list by the previous loop.
2293                  */
2294                 if (!net_eq(dev_net(t->dev), net))
2295                         unregister_netdevice_queue(t->dev, list);
2296                 t = rtnl_dereference(t->next);
2297         }
2298 }
2299
2300 static int __net_init ip6_tnl_init_net(struct net *net)
2301 {
2302         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2303         struct ip6_tnl *t = NULL;
2304         int err;
2305
2306         ip6n->tnls[0] = ip6n->tnls_wc;
2307         ip6n->tnls[1] = ip6n->tnls_r_l;
2308
2309         if (!net_has_fallback_tunnels(net))
2310                 return 0;
2311         err = -ENOMEM;
2312         ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2313                                         NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2314
2315         if (!ip6n->fb_tnl_dev)
2316                 goto err_alloc_dev;
2317         dev_net_set(ip6n->fb_tnl_dev, net);
2318         ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2319         /* FB netdevice is special: we have one, and only one per netns.
2320          * Allowing to move it to another netns is clearly unsafe.
2321          */
2322         ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2323
2324         err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2325         if (err < 0)
2326                 goto err_register;
2327
2328         err = register_netdev(ip6n->fb_tnl_dev);
2329         if (err < 0)
2330                 goto err_register;
2331
2332         t = netdev_priv(ip6n->fb_tnl_dev);
2333
2334         strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2335         return 0;
2336
2337 err_register:
2338         free_netdev(ip6n->fb_tnl_dev);
2339 err_alloc_dev:
2340         return err;
2341 }
2342
2343 static void __net_exit ip6_tnl_exit_batch_net(struct list_head *net_list)
2344 {
2345         struct net *net;
2346         LIST_HEAD(list);
2347
2348         rtnl_lock();
2349         list_for_each_entry(net, net_list, exit_list)
2350                 ip6_tnl_destroy_tunnels(net, &list);
2351         unregister_netdevice_many(&list);
2352         rtnl_unlock();
2353 }
2354
2355 static struct pernet_operations ip6_tnl_net_ops = {
2356         .init = ip6_tnl_init_net,
2357         .exit_batch = ip6_tnl_exit_batch_net,
2358         .id   = &ip6_tnl_net_id,
2359         .size = sizeof(struct ip6_tnl_net),
2360 };
2361
2362 /**
2363  * ip6_tunnel_init - register protocol and reserve needed resources
2364  *
2365  * Return: 0 on success
2366  **/
2367
2368 static int __init ip6_tunnel_init(void)
2369 {
2370         int  err;
2371
2372         if (!ipv6_mod_enabled())
2373                 return -EOPNOTSUPP;
2374
2375         err = register_pernet_device(&ip6_tnl_net_ops);
2376         if (err < 0)
2377                 goto out_pernet;
2378
2379         err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2380         if (err < 0) {
2381                 pr_err("%s: can't register ip4ip6\n", __func__);
2382                 goto out_ip4ip6;
2383         }
2384
2385         err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2386         if (err < 0) {
2387                 pr_err("%s: can't register ip6ip6\n", __func__);
2388                 goto out_ip6ip6;
2389         }
2390
2391         if (ip6_tnl_mpls_supported()) {
2392                 err = xfrm6_tunnel_register(&mplsip6_handler, AF_MPLS);
2393                 if (err < 0) {
2394                         pr_err("%s: can't register mplsip6\n", __func__);
2395                         goto out_mplsip6;
2396                 }
2397         }
2398
2399         err = rtnl_link_register(&ip6_link_ops);
2400         if (err < 0)
2401                 goto rtnl_link_failed;
2402
2403         return 0;
2404
2405 rtnl_link_failed:
2406         if (ip6_tnl_mpls_supported())
2407                 xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS);
2408 out_mplsip6:
2409         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2410 out_ip6ip6:
2411         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2412 out_ip4ip6:
2413         unregister_pernet_device(&ip6_tnl_net_ops);
2414 out_pernet:
2415         return err;
2416 }
2417
2418 /**
2419  * ip6_tunnel_cleanup - free resources and unregister protocol
2420  **/
2421
2422 static void __exit ip6_tunnel_cleanup(void)
2423 {
2424         rtnl_link_unregister(&ip6_link_ops);
2425         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2426                 pr_info("%s: can't deregister ip4ip6\n", __func__);
2427
2428         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2429                 pr_info("%s: can't deregister ip6ip6\n", __func__);
2430
2431         if (ip6_tnl_mpls_supported() &&
2432             xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS))
2433                 pr_info("%s: can't deregister mplsip6\n", __func__);
2434         unregister_pernet_device(&ip6_tnl_net_ops);
2435 }
2436
2437 module_init(ip6_tunnel_init);
2438 module_exit(ip6_tunnel_cleanup);