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 <linux/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 #include <net/dst_metadata.h>
  61
  62 MODULE_AUTHOR("Ville Nuorvala");
  63 MODULE_DESCRIPTION("IPv6 tunneling device");
  64 MODULE_LICENSE("GPL");
  65 MODULE_ALIAS_RTNL_LINK("ip6tnl");
  66 MODULE_ALIAS_NETDEV("ip6tnl0");
  67
  68 #define IP6_TUNNEL_HASH_SIZE_SHIFT  5
  69 #define IP6_TUNNEL_HASH_SIZE (1 << IP6_TUNNEL_HASH_SIZE_SHIFT)
  70
  71 static bool log_ecn_error = true;
  72 module_param(log_ecn_error, bool, 0644);
  73 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  74
  75 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
  76 {
  77         u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
  78
  79         return hash_32(hash, IP6_TUNNEL_HASH_SIZE_SHIFT);
  80 }
  81
  82 static int ip6_tnl_dev_init(struct net_device *dev);
  83 static void ip6_tnl_dev_setup(struct net_device *dev);
  84 static struct rtnl_link_ops ip6_link_ops __read_mostly;
  85
  86 static unsigned int ip6_tnl_net_id __read_mostly;
  87 struct ip6_tnl_net {
  88         /* the IPv6 tunnel fallback device */
  89         struct net_device *fb_tnl_dev;
  90         /* lists for storing tunnels in use */
  91         struct ip6_tnl __rcu *tnls_r_l[IP6_TUNNEL_HASH_SIZE];
  92         struct ip6_tnl __rcu *tnls_wc[1];
  93         struct ip6_tnl __rcu **tnls[2];
  94         struct ip6_tnl __rcu *collect_md_tun;
  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 /**
 128  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
 129  *   @remote: the address of the tunnel exit-point
 130  *   @local: the address of the tunnel entry-point
 131  *
 132  * Return:
 133  *   tunnel matching given end-points if found,
 134  *   else fallback tunnel if its device is up,
 135  *   else %NULL
 136  **/
 137
 138 #define for_each_ip6_tunnel_rcu(start) \
 139         for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
 140
 141 static struct ip6_tnl *
 142 ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local)
 143 {
 144         unsigned int hash = HASH(remote, local);
 145         struct ip6_tnl *t;
 146         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 147         struct in6_addr any;
 148
 149         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 150                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 151                     ipv6_addr_equal(remote, &t->parms.raddr) &&
 152                     (t->dev->flags & IFF_UP))
 153                         return t;
 154         }
 155
 156         memset(&any, 0, sizeof(any));
 157         hash = HASH(&any, local);
 158         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 159                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 160                     ipv6_addr_any(&t->parms.raddr) &&
 161                     (t->dev->flags & IFF_UP))
 162                         return t;
 163         }
 164
 165         hash = HASH(remote, &any);
 166         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 167                 if (ipv6_addr_equal(remote, &t->parms.raddr) &&
 168                     ipv6_addr_any(&t->parms.laddr) &&
 169                     (t->dev->flags & IFF_UP))
 170                         return t;
 171         }
 172
 173         t = rcu_dereference(ip6n->collect_md_tun);
 174         if (t && t->dev->flags & IFF_UP)
 175                 return t;
 176
 177         t = rcu_dereference(ip6n->tnls_wc[0]);
 178         if (t && (t->dev->flags & IFF_UP))
 179                 return t;
 180
 181         return NULL;
 182 }
 183
 184 /**
 185  * ip6_tnl_bucket - get head of list matching given tunnel parameters
 186  *   @p: parameters containing tunnel end-points
 187  *
 188  * Description:
 189  *   ip6_tnl_bucket() returns the head of the list matching the
 190  *   &struct in6_addr entries laddr and raddr in @p.
 191  *
 192  * Return: head of IPv6 tunnel list
 193  **/
 194
 195 static struct ip6_tnl __rcu **
 196 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
 197 {
 198         const struct in6_addr *remote = &p->raddr;
 199         const struct in6_addr *local = &p->laddr;
 200         unsigned int h = 0;
 201         int prio = 0;
 202
 203         if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
 204                 prio = 1;
 205                 h = HASH(remote, local);
 206         }
 207         return &ip6n->tnls[prio][h];
 208 }
 209
 210 /**
 211  * ip6_tnl_link - add tunnel to hash table
 212  *   @t: tunnel to be added
 213  **/
 214
 215 static void
 216 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 217 {
 218         struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
 219
 220         if (t->parms.collect_md)
 221                 rcu_assign_pointer(ip6n->collect_md_tun, t);
 222         rcu_assign_pointer(t->next , rtnl_dereference(*tp));
 223         rcu_assign_pointer(*tp, t);
 224 }
 225
 226 /**
 227  * ip6_tnl_unlink - remove tunnel from hash table
 228  *   @t: tunnel to be removed
 229  **/
 230
 231 static void
 232 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 233 {
 234         struct ip6_tnl __rcu **tp;
 235         struct ip6_tnl *iter;
 236
 237         if (t->parms.collect_md)
 238                 rcu_assign_pointer(ip6n->collect_md_tun, NULL);
 239
 240         for (tp = ip6_tnl_bucket(ip6n, &t->parms);
 241              (iter = rtnl_dereference(*tp)) != NULL;
 242              tp = &iter->next) {
 243                 if (t == iter) {
 244                         rcu_assign_pointer(*tp, t->next);
 245                         break;
 246                 }
 247         }
 248 }
 249
 250 static void ip6_dev_free(struct net_device *dev)
 251 {
 252         struct ip6_tnl *t = netdev_priv(dev);
 253
 254         gro_cells_destroy(&t->gro_cells);
 255         dst_cache_destroy(&t->dst_cache);
 256         free_percpu(dev->tstats);
 257 }
 258
 259 static int ip6_tnl_create2(struct net_device *dev)
 260 {
 261         struct ip6_tnl *t = netdev_priv(dev);
 262         struct net *net = dev_net(dev);
 263         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 264         int err;
 265
 266         t = netdev_priv(dev);
 267
 268         dev->rtnl_link_ops = &ip6_link_ops;
 269         err = register_netdevice(dev);
 270         if (err < 0)
 271                 goto out;
 272
 273         strcpy(t->parms.name, dev->name);
 274
 275         dev_hold(dev);
 276         ip6_tnl_link(ip6n, t);
 277         return 0;
 278
 279 out:
 280         return err;
 281 }
 282
 283 /**
 284  * ip6_tnl_create - create a new tunnel
 285  *   @p: tunnel parameters
 286  *   @pt: pointer to new tunnel
 287  *
 288  * Description:
 289  *   Create tunnel matching given parameters.
 290  *
 291  * Return:
 292  *   created tunnel or error pointer
 293  **/
 294
 295 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
 296 {
 297         struct net_device *dev;
 298         struct ip6_tnl *t;
 299         char name[IFNAMSIZ];
 300         int err = -E2BIG;
 301
 302         if (p->name[0]) {
 303                 if (!dev_valid_name(p->name))
 304                         goto failed;
 305                 strlcpy(name, p->name, IFNAMSIZ);
 306         } else {
 307                 sprintf(name, "ip6tnl%%d");
 308         }
 309         err = -ENOMEM;
 310         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 311                            ip6_tnl_dev_setup);
 312         if (!dev)
 313                 goto failed;
 314
 315         dev_net_set(dev, net);
 316
 317         t = netdev_priv(dev);
 318         t->parms = *p;
 319         t->net = dev_net(dev);
 320         err = ip6_tnl_create2(dev);
 321         if (err < 0)
 322                 goto failed_free;
 323
 324         return t;
 325
 326 failed_free:
 327         free_netdev(dev);
 328 failed:
 329         return ERR_PTR(err);
 330 }
 331
 332 /**
 333  * ip6_tnl_locate - find or create tunnel matching given parameters
 334  *   @p: tunnel parameters
 335  *   @create: != 0 if allowed to create new tunnel if no match found
 336  *
 337  * Description:
 338  *   ip6_tnl_locate() first tries to locate an existing tunnel
 339  *   based on @parms. If this is unsuccessful, but @create is set a new
 340  *   tunnel device is created and registered for use.
 341  *
 342  * Return:
 343  *   matching tunnel or error pointer
 344  **/
 345
 346 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
 347                 struct __ip6_tnl_parm *p, int create)
 348 {
 349         const struct in6_addr *remote = &p->raddr;
 350         const struct in6_addr *local = &p->laddr;
 351         struct ip6_tnl __rcu **tp;
 352         struct ip6_tnl *t;
 353         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 354
 355         for (tp = ip6_tnl_bucket(ip6n, p);
 356              (t = rtnl_dereference(*tp)) != NULL;
 357              tp = &t->next) {
 358                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 359                     ipv6_addr_equal(remote, &t->parms.raddr)) {
 360                         if (create)
 361                                 return ERR_PTR(-EEXIST);
 362
 363                         return t;
 364                 }
 365         }
 366         if (!create)
 367                 return ERR_PTR(-ENODEV);
 368         return ip6_tnl_create(net, p);
 369 }
 370
 371 /**
 372  * ip6_tnl_dev_uninit - tunnel device uninitializer
 373  *   @dev: the device to be destroyed
 374  *
 375  * Description:
 376  *   ip6_tnl_dev_uninit() removes tunnel from its list
 377  **/
 378
 379 static void
 380 ip6_tnl_dev_uninit(struct net_device *dev)
 381 {
 382         struct ip6_tnl *t = netdev_priv(dev);
 383         struct net *net = t->net;
 384         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 385
 386         if (dev == ip6n->fb_tnl_dev)
 387                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
 388         else
 389                 ip6_tnl_unlink(ip6n, t);
 390         dst_cache_reset(&t->dst_cache);
 391         dev_put(dev);
 392 }
 393
 394 /**
 395  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
 396  *   @skb: received socket buffer
 397  *
 398  * Return:
 399  *   0 if none was found,
 400  *   else index to encapsulation limit
 401  **/
 402
 403 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
 404 {
 405         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)raw;
 406         unsigned int nhoff = raw - skb->data;
 407         unsigned int off = nhoff + sizeof(*ipv6h);
 408         u8 next, nexthdr = ipv6h->nexthdr;
 409
 410         while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
 411                 struct ipv6_opt_hdr *hdr;
 412                 u16 optlen;
 413
 414                 if (!pskb_may_pull(skb, off + sizeof(*hdr)))
 415                         break;
 416
 417                 hdr = (struct ipv6_opt_hdr *)(skb->data + off);
 418                 if (nexthdr == NEXTHDR_FRAGMENT) {
 419                         struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
 420                         if (frag_hdr->frag_off)
 421                                 break;
 422                         optlen = 8;
 423                 } else if (nexthdr == NEXTHDR_AUTH) {
 424                         optlen = (hdr->hdrlen + 2) << 2;
 425                 } else {
 426                         optlen = ipv6_optlen(hdr);
 427                 }
 428                 /* cache hdr->nexthdr, since pskb_may_pull() might
 429                  * invalidate hdr
 430                  */
 431                 next = hdr->nexthdr;
 432                 if (nexthdr == NEXTHDR_DEST) {
 433                         u16 i = 2;
 434
 435                         /* Remember : hdr is no longer valid at this point. */
 436                         if (!pskb_may_pull(skb, off + optlen))
 437                                 break;
 438
 439                         while (1) {
 440                                 struct ipv6_tlv_tnl_enc_lim *tel;
 441
 442                                 /* No more room for encapsulation limit */
 443                                 if (i + sizeof(*tel) > optlen)
 444                                         break;
 445
 446                                 tel = (struct ipv6_tlv_tnl_enc_lim *)(skb->data + off + i);
 447                                 /* return index of option if found and valid */
 448                                 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
 449                                     tel->length == 1)
 450                                         return i + off - nhoff;
 451                                 /* else jump to next option */
 452                                 if (tel->type)
 453                                         i += tel->length + 2;
 454                                 else
 455                                         i++;
 456                         }
 457                 }
 458                 nexthdr = next;
 459                 off += optlen;
 460         }
 461         return 0;
 462 }
 463 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
 464
 465 /**
 466  * ip6_tnl_err - tunnel error handler
 467  *
 468  * Description:
 469  *   ip6_tnl_err() should handle errors in the tunnel according
 470  *   to the specifications in RFC 2473.
 471  **/
 472
 473 static int
 474 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
 475             u8 *type, u8 *code, int *msg, __u32 *info, int offset)
 476 {
 477         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 478         struct net *net = dev_net(skb->dev);
 479         u8 rel_type = ICMPV6_DEST_UNREACH;
 480         u8 rel_code = ICMPV6_ADDR_UNREACH;
 481         __u32 rel_info = 0;
 482         struct ip6_tnl *t;
 483         int err = -ENOENT;
 484         int rel_msg = 0;
 485         u8 tproto;
 486         __u16 len;
 487
 488         /* If the packet doesn't contain the original IPv6 header we are
 489            in trouble since we might need the source address for further
 490            processing of the error. */
 491
 492         rcu_read_lock();
 493         t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, &ipv6h->saddr);
 494         if (!t)
 495                 goto out;
 496
 497         tproto = READ_ONCE(t->parms.proto);
 498         if (tproto != ipproto && tproto != 0)
 499                 goto out;
 500
 501         err = 0;
 502
 503         switch (*type) {
 504                 struct ipv6_tlv_tnl_enc_lim *tel;
 505                 __u32 mtu, teli;
 506         case ICMPV6_DEST_UNREACH:
 507                 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
 508                                     t->parms.name);
 509                 rel_msg = 1;
 510                 break;
 511         case ICMPV6_TIME_EXCEED:
 512                 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
 513                         net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 514                                             t->parms.name);
 515                         rel_msg = 1;
 516                 }
 517                 break;
 518         case ICMPV6_PARAMPROB:
 519                 teli = 0;
 520                 if ((*code) == ICMPV6_HDR_FIELD)
 521                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 522
 523                 if (teli && teli == *info - 2) {
 524                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 525                         if (tel->encap_limit == 0) {
 526                                 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 527                                                     t->parms.name);
 528                                 rel_msg = 1;
 529                         }
 530                 } else {
 531                         net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 532                                             t->parms.name);
 533                 }
 534                 break;
 535         case ICMPV6_PKT_TOOBIG:
 536                 ip6_update_pmtu(skb, net, htonl(*info), 0, 0,
 537                                 sock_net_uid(net, NULL));
 538                 mtu = *info - offset;
 539                 if (mtu < IPV6_MIN_MTU)
 540                         mtu = IPV6_MIN_MTU;
 541                 len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
 542                 if (len > mtu) {
 543                         rel_type = ICMPV6_PKT_TOOBIG;
 544                         rel_code = 0;
 545                         rel_info = mtu;
 546                         rel_msg = 1;
 547                 }
 548                 break;
 549         case NDISC_REDIRECT:
 550                 ip6_redirect(skb, net, skb->dev->ifindex, 0,
 551                              sock_net_uid(net, NULL));
 552                 break;
 553         }
 554
 555         *type = rel_type;
 556         *code = rel_code;
 557         *info = rel_info;
 558         *msg = rel_msg;
 559
 560 out:
 561         rcu_read_unlock();
 562         return err;
 563 }
 564
 565 static int
 566 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 567            u8 type, u8 code, int offset, __be32 info)
 568 {
 569         __u32 rel_info = ntohl(info);
 570         const struct iphdr *eiph;
 571         struct sk_buff *skb2;
 572         int err, rel_msg = 0;
 573         u8 rel_type = type;
 574         u8 rel_code = code;
 575         struct rtable *rt;
 576         struct flowi4 fl4;
 577
 578         err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
 579                           &rel_msg, &rel_info, offset);
 580         if (err < 0)
 581                 return err;
 582
 583         if (rel_msg == 0)
 584                 return 0;
 585
 586         switch (rel_type) {
 587         case ICMPV6_DEST_UNREACH:
 588                 if (rel_code != ICMPV6_ADDR_UNREACH)
 589                         return 0;
 590                 rel_type = ICMP_DEST_UNREACH;
 591                 rel_code = ICMP_HOST_UNREACH;
 592                 break;
 593         case ICMPV6_PKT_TOOBIG:
 594                 if (rel_code != 0)
 595                         return 0;
 596                 rel_type = ICMP_DEST_UNREACH;
 597                 rel_code = ICMP_FRAG_NEEDED;
 598                 break;
 599         default:
 600                 return 0;
 601         }
 602
 603         if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
 604                 return 0;
 605
 606         skb2 = skb_clone(skb, GFP_ATOMIC);
 607         if (!skb2)
 608                 return 0;
 609
 610         skb_dst_drop(skb2);
 611
 612         skb_pull(skb2, offset);
 613         skb_reset_network_header(skb2);
 614         eiph = ip_hdr(skb2);
 615
 616         /* Try to guess incoming interface */
 617         rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, eiph->saddr,
 618                                    0, 0, 0, IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 619         if (IS_ERR(rt))
 620                 goto out;
 621
 622         skb2->dev = rt->dst.dev;
 623         ip_rt_put(rt);
 624
 625         /* route "incoming" packet */
 626         if (rt->rt_flags & RTCF_LOCAL) {
 627                 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 628                                            eiph->daddr, eiph->saddr, 0, 0,
 629                                            IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 630                 if (IS_ERR(rt) || rt->dst.dev->type != ARPHRD_TUNNEL) {
 631                         if (!IS_ERR(rt))
 632                                 ip_rt_put(rt);
 633                         goto out;
 634                 }
 635                 skb_dst_set(skb2, &rt->dst);
 636         } else {
 637                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
 638                                    skb2->dev) ||
 639                     skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
 640                         goto out;
 641         }
 642
 643         /* change mtu on this route */
 644         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
 645                 if (rel_info > dst_mtu(skb_dst(skb2)))
 646                         goto out;
 647
 648                 skb_dst_update_pmtu(skb2, rel_info);
 649         }
 650
 651         icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
 652
 653 out:
 654         kfree_skb(skb2);
 655         return 0;
 656 }
 657
 658 static int
 659 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 660            u8 type, u8 code, int offset, __be32 info)
 661 {
 662         __u32 rel_info = ntohl(info);
 663         int err, rel_msg = 0;
 664         u8 rel_type = type;
 665         u8 rel_code = code;
 666
 667         err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
 668                           &rel_msg, &rel_info, offset);
 669         if (err < 0)
 670                 return err;
 671
 672         if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
 673                 struct rt6_info *rt;
 674                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 675
 676                 if (!skb2)
 677                         return 0;
 678
 679                 skb_dst_drop(skb2);
 680                 skb_pull(skb2, offset);
 681                 skb_reset_network_header(skb2);
 682
 683                 /* Try to guess incoming interface */
 684                 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
 685                                 NULL, 0, skb2, 0);
 686
 687                 if (rt && rt->dst.dev)
 688                         skb2->dev = rt->dst.dev;
 689
 690                 icmpv6_send(skb2, rel_type, rel_code, rel_info);
 691
 692                 ip6_rt_put(rt);
 693
 694                 kfree_skb(skb2);
 695         }
 696
 697         return 0;
 698 }
 699
 700 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 701                                        const struct ipv6hdr *ipv6h,
 702                                        struct sk_buff *skb)
 703 {
 704         __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
 705
 706         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 707                 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
 708
 709         return IP6_ECN_decapsulate(ipv6h, skb);
 710 }
 711
 712 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 713                                        const struct ipv6hdr *ipv6h,
 714                                        struct sk_buff *skb)
 715 {
 716         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 717                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
 718
 719         return IP6_ECN_decapsulate(ipv6h, skb);
 720 }
 721
 722 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
 723                              const struct in6_addr *laddr,
 724                              const struct in6_addr *raddr)
 725 {
 726         struct __ip6_tnl_parm *p = &t->parms;
 727         int ltype = ipv6_addr_type(laddr);
 728         int rtype = ipv6_addr_type(raddr);
 729         __u32 flags = 0;
 730
 731         if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
 732                 flags = IP6_TNL_F_CAP_PER_PACKET;
 733         } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 734                    rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 735                    !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
 736                    (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
 737                 if (ltype&IPV6_ADDR_UNICAST)
 738                         flags |= IP6_TNL_F_CAP_XMIT;
 739                 if (rtype&IPV6_ADDR_UNICAST)
 740                         flags |= IP6_TNL_F_CAP_RCV;
 741         }
 742         return flags;
 743 }
 744 EXPORT_SYMBOL(ip6_tnl_get_cap);
 745
 746 /* called with rcu_read_lock() */
 747 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
 748                                   const struct in6_addr *laddr,
 749                                   const struct in6_addr *raddr)
 750 {
 751         struct __ip6_tnl_parm *p = &t->parms;
 752         int ret = 0;
 753         struct net *net = t->net;
 754
 755         if ((p->flags & IP6_TNL_F_CAP_RCV) ||
 756             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
 757              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
 758                 struct net_device *ldev = NULL;
 759
 760                 if (p->link)
 761                         ldev = dev_get_by_index_rcu(net, p->link);
 762
 763                 if ((ipv6_addr_is_multicast(laddr) ||
 764                      likely(ipv6_chk_addr_and_flags(net, laddr, ldev, false,
 765                                                     0, IFA_F_TENTATIVE))) &&
 766                     ((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
 767                      likely(!ipv6_chk_addr_and_flags(net, raddr, ldev, true,
 768                                                      0, IFA_F_TENTATIVE))))
 769                         ret = 1;
 770         }
 771         return ret;
 772 }
 773 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
 774
 775 static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
 776                          const struct tnl_ptk_info *tpi,
 777                          struct metadata_dst *tun_dst,
 778                          int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 779                                                 const struct ipv6hdr *ipv6h,
 780                                                 struct sk_buff *skb),
 781                          bool log_ecn_err)
 782 {
 783         struct pcpu_sw_netstats *tstats;
 784         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 785         int err;
 786
 787         if ((!(tpi->flags & TUNNEL_CSUM) &&
 788              (tunnel->parms.i_flags & TUNNEL_CSUM)) ||
 789             ((tpi->flags & TUNNEL_CSUM) &&
 790              !(tunnel->parms.i_flags & TUNNEL_CSUM))) {
 791                 tunnel->dev->stats.rx_crc_errors++;
 792                 tunnel->dev->stats.rx_errors++;
 793                 goto drop;
 794         }
 795
 796         if (tunnel->parms.i_flags & TUNNEL_SEQ) {
 797                 if (!(tpi->flags & TUNNEL_SEQ) ||
 798                     (tunnel->i_seqno &&
 799                      (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
 800                         tunnel->dev->stats.rx_fifo_errors++;
 801                         tunnel->dev->stats.rx_errors++;
 802                         goto drop;
 803                 }
 804                 tunnel->i_seqno = ntohl(tpi->seq) + 1;
 805         }
 806
 807         skb->protocol = tpi->proto;
 808
 809         /* Warning: All skb pointers will be invalidated! */
 810         if (tunnel->dev->type == ARPHRD_ETHER) {
 811                 if (!pskb_may_pull(skb, ETH_HLEN)) {
 812                         tunnel->dev->stats.rx_length_errors++;
 813                         tunnel->dev->stats.rx_errors++;
 814                         goto drop;
 815                 }
 816
 817                 ipv6h = ipv6_hdr(skb);
 818                 skb->protocol = eth_type_trans(skb, tunnel->dev);
 819                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 820         } else {
 821                 skb->dev = tunnel->dev;
 822         }
 823
 824         skb_reset_network_header(skb);
 825         memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 826
 827         __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 828
 829         err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
 830         if (unlikely(err)) {
 831                 if (log_ecn_err)
 832                         net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
 833                                              &ipv6h->saddr,
 834                                              ipv6_get_dsfield(ipv6h));
 835                 if (err > 1) {
 836                         ++tunnel->dev->stats.rx_frame_errors;
 837                         ++tunnel->dev->stats.rx_errors;
 838                         goto drop;
 839                 }
 840         }
 841
 842         tstats = this_cpu_ptr(tunnel->dev->tstats);
 843         u64_stats_update_begin(&tstats->syncp);
 844         tstats->rx_packets++;
 845         tstats->rx_bytes += skb->len;
 846         u64_stats_update_end(&tstats->syncp);
 847
 848         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
 849
 850         if (tun_dst)
 851                 skb_dst_set(skb, (struct dst_entry *)tun_dst);
 852
 853         gro_cells_receive(&tunnel->gro_cells, skb);
 854         return 0;
 855
 856 drop:
 857         if (tun_dst)
 858                 dst_release((struct dst_entry *)tun_dst);
 859         kfree_skb(skb);
 860         return 0;
 861 }
 862
 863 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
 864                 const struct tnl_ptk_info *tpi,
 865                 struct metadata_dst *tun_dst,
 866                 bool log_ecn_err)
 867 {
 868         return __ip6_tnl_rcv(t, skb, tpi, tun_dst, ip6ip6_dscp_ecn_decapsulate,
 869                              log_ecn_err);
 870 }
 871 EXPORT_SYMBOL(ip6_tnl_rcv);
 872
 873 static const struct tnl_ptk_info tpi_v6 = {
 874         /* no tunnel info required for ipxip6. */
 875         .proto = htons(ETH_P_IPV6),
 876 };
 877
 878 static const struct tnl_ptk_info tpi_v4 = {
 879         /* no tunnel info required for ipxip6. */
 880         .proto = htons(ETH_P_IP),
 881 };
 882
 883 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
 884                       const struct tnl_ptk_info *tpi,
 885                       int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 886                                                   const struct ipv6hdr *ipv6h,
 887                                                   struct sk_buff *skb))
 888 {
 889         struct ip6_tnl *t;
 890         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 891         struct metadata_dst *tun_dst = NULL;
 892         int ret = -1;
 893
 894         rcu_read_lock();
 895         t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
 896
 897         if (t) {
 898                 u8 tproto = READ_ONCE(t->parms.proto);
 899
 900                 if (tproto != ipproto && tproto != 0)
 901                         goto drop;
 902                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 903                         goto drop;
 904                 ipv6h = ipv6_hdr(skb);
 905                 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
 906                         goto drop;
 907                 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
 908                         goto drop;
 909                 if (t->parms.collect_md) {
 910                         tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
 911                         if (!tun_dst)
 912                                 goto drop;
 913                 }
 914                 ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
 915                                     log_ecn_error);
 916         }
 917
 918         rcu_read_unlock();
 919
 920         return ret;
 921
 922 drop:
 923         rcu_read_unlock();
 924         kfree_skb(skb);
 925         return 0;
 926 }
 927
 928 static int ip4ip6_rcv(struct sk_buff *skb)
 929 {
 930         return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
 931                           ip4ip6_dscp_ecn_decapsulate);
 932 }
 933
 934 static int ip6ip6_rcv(struct sk_buff *skb)
 935 {
 936         return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
 937                           ip6ip6_dscp_ecn_decapsulate);
 938 }
 939
 940 struct ipv6_tel_txoption {
 941         struct ipv6_txoptions ops;
 942         __u8 dst_opt[8];
 943 };
 944
 945 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 946 {
 947         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 948
 949         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 950         opt->dst_opt[3] = 1;
 951         opt->dst_opt[4] = encap_limit;
 952         opt->dst_opt[5] = IPV6_TLV_PADN;
 953         opt->dst_opt[6] = 1;
 954
 955         opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 956         opt->ops.opt_nflen = 8;
 957 }
 958
 959 /**
 960  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 961  *   @t: the outgoing tunnel device
 962  *   @hdr: IPv6 header from the incoming packet
 963  *
 964  * Description:
 965  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 966  *   doesn't match source of incoming packet.
 967  *
 968  * Return:
 969  *   1 if conflict,
 970  *   0 else
 971  **/
 972
 973 static inline bool
 974 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
 975 {
 976         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 977 }
 978
 979 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
 980                      const struct in6_addr *laddr,
 981                      const struct in6_addr *raddr)
 982 {
 983         struct __ip6_tnl_parm *p = &t->parms;
 984         int ret = 0;
 985         struct net *net = t->net;
 986
 987         if (t->parms.collect_md)
 988                 return 1;
 989
 990         if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
 991             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
 992              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
 993                 struct net_device *ldev = NULL;
 994
 995                 rcu_read_lock();
 996                 if (p->link)
 997                         ldev = dev_get_by_index_rcu(net, p->link);
 998
 999                 if (unlikely(!ipv6_chk_addr_and_flags(net, laddr, ldev, false,
1000                                                       0, IFA_F_TENTATIVE)))
1001                         pr_warn("%s xmit: Local address not yet configured!\n",
1002                                 p->name);
1003                 else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
1004                          !ipv6_addr_is_multicast(raddr) &&
1005                          unlikely(ipv6_chk_addr_and_flags(net, raddr, ldev,
1006                                                           true, 0, IFA_F_TENTATIVE)))
1007                         pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
1008                                 p->name);
1009                 else
1010                         ret = 1;
1011                 rcu_read_unlock();
1012         }
1013         return ret;
1014 }
1015 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1016
1017 /**
1018  * ip6_tnl_xmit - encapsulate packet and send
1019  *   @skb: the outgoing socket buffer
1020  *   @dev: the outgoing tunnel device
1021  *   @dsfield: dscp code for outer header
1022  *   @fl6: flow of tunneled packet
1023  *   @encap_limit: encapsulation limit
1024  *   @pmtu: Path MTU is stored if packet is too big
1025  *   @proto: next header value
1026  *
1027  * Description:
1028  *   Build new header and do some sanity checks on the packet before sending
1029  *   it.
1030  *
1031  * Return:
1032  *   0 on success
1033  *   -1 fail
1034  *   %-EMSGSIZE message too big. return mtu in this case.
1035  **/
1036
1037 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1038                  struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1039                  __u8 proto)
1040 {
1041         struct ip6_tnl *t = netdev_priv(dev);
1042         struct net *net = t->net;
1043         struct net_device_stats *stats = &t->dev->stats;
1044         struct ipv6hdr *ipv6h;
1045         struct ipv6_tel_txoption opt;
1046         struct dst_entry *dst = NULL, *ndst = NULL;
1047         struct net_device *tdev;
1048         int mtu;
1049         unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1050         unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1051         unsigned int max_headroom = psh_hlen;
1052         bool use_cache = false;
1053         u8 hop_limit;
1054         int err = -1;
1055
1056         if (t->parms.collect_md) {
1057                 hop_limit = skb_tunnel_info(skb)->key.ttl;
1058                 goto route_lookup;
1059         } else {
1060                 hop_limit = t->parms.hop_limit;
1061         }
1062
1063         /* NBMA tunnel */
1064         if (ipv6_addr_any(&t->parms.raddr)) {
1065                 if (skb->protocol == htons(ETH_P_IPV6)) {
1066                         struct in6_addr *addr6;
1067                         struct neighbour *neigh;
1068                         int addr_type;
1069
1070                         if (!skb_dst(skb))
1071                                 goto tx_err_link_failure;
1072
1073                         neigh = dst_neigh_lookup(skb_dst(skb),
1074                                                  &ipv6_hdr(skb)->daddr);
1075                         if (!neigh)
1076                                 goto tx_err_link_failure;
1077
1078                         addr6 = (struct in6_addr *)&neigh->primary_key;
1079                         addr_type = ipv6_addr_type(addr6);
1080
1081                         if (addr_type == IPV6_ADDR_ANY)
1082                                 addr6 = &ipv6_hdr(skb)->daddr;
1083
1084                         memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1085                         neigh_release(neigh);
1086                 }
1087         } else if (t->parms.proto != 0 && !(t->parms.flags &
1088                                             (IP6_TNL_F_USE_ORIG_TCLASS |
1089                                              IP6_TNL_F_USE_ORIG_FWMARK))) {
1090                 /* enable the cache only if neither the outer protocol nor the
1091                  * routing decision depends on the current inner header value
1092                  */
1093                 use_cache = true;
1094         }
1095
1096         if (use_cache)
1097                 dst = dst_cache_get(&t->dst_cache);
1098
1099         if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1100                 goto tx_err_link_failure;
1101
1102         if (!dst) {
1103 route_lookup:
1104                 /* add dsfield to flowlabel for route lookup */
1105                 fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1106
1107                 dst = ip6_route_output(net, NULL, fl6);
1108
1109                 if (dst->error)
1110                         goto tx_err_link_failure;
1111                 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1112                 if (IS_ERR(dst)) {
1113                         err = PTR_ERR(dst);
1114                         dst = NULL;
1115                         goto tx_err_link_failure;
1116                 }
1117                 if (t->parms.collect_md && ipv6_addr_any(&fl6->saddr) &&
1118                     ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1119                                        &fl6->daddr, 0, &fl6->saddr))
1120                         goto tx_err_link_failure;
1121                 ndst = dst;
1122         }
1123
1124         tdev = dst->dev;
1125
1126         if (tdev == dev) {
1127                 stats->collisions++;
1128                 net_warn_ratelimited("%s: Local routing loop detected!\n",
1129                                      t->parms.name);
1130                 goto tx_err_dst_release;
1131         }
1132         mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
1133         if (encap_limit >= 0) {
1134                 max_headroom += 8;
1135                 mtu -= 8;
1136         }
1137         mtu = max(mtu, skb->protocol == htons(ETH_P_IPV6) ?
1138                        IPV6_MIN_MTU : IPV4_MIN_MTU);
1139
1140         skb_dst_update_pmtu(skb, mtu);
1141         if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
1142                 *pmtu = mtu;
1143                 err = -EMSGSIZE;
1144                 goto tx_err_dst_release;
1145         }
1146
1147         if (t->err_count > 0) {
1148                 if (time_before(jiffies,
1149                                 t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1150                         t->err_count--;
1151
1152                         dst_link_failure(skb);
1153                 } else {
1154                         t->err_count = 0;
1155                 }
1156         }
1157
1158         skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1159
1160         /*
1161          * Okay, now see if we can stuff it in the buffer as-is.
1162          */
1163         max_headroom += LL_RESERVED_SPACE(tdev);
1164
1165         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1166             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1167                 struct sk_buff *new_skb;
1168
1169                 new_skb = skb_realloc_headroom(skb, max_headroom);
1170                 if (!new_skb)
1171                         goto tx_err_dst_release;
1172
1173                 if (skb->sk)
1174                         skb_set_owner_w(new_skb, skb->sk);
1175                 consume_skb(skb);
1176                 skb = new_skb;
1177         }
1178
1179         if (t->parms.collect_md) {
1180                 if (t->encap.type != TUNNEL_ENCAP_NONE)
1181                         goto tx_err_dst_release;
1182         } else {
1183                 if (use_cache && ndst)
1184                         dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1185         }
1186         skb_dst_set(skb, dst);
1187
1188         if (hop_limit == 0) {
1189                 if (skb->protocol == htons(ETH_P_IP))
1190                         hop_limit = ip_hdr(skb)->ttl;
1191                 else if (skb->protocol == htons(ETH_P_IPV6))
1192                         hop_limit = ipv6_hdr(skb)->hop_limit;
1193                 else
1194                         hop_limit = ip6_dst_hoplimit(dst);
1195         }
1196
1197         /* Calculate max headroom for all the headers and adjust
1198          * needed_headroom if necessary.
1199          */
1200         max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1201                         + dst->header_len + t->hlen;
1202         if (max_headroom > dev->needed_headroom)
1203                 dev->needed_headroom = max_headroom;
1204
1205         err = ip6_tnl_encap(skb, t, &proto, fl6);
1206         if (err)
1207                 return err;
1208
1209         if (encap_limit >= 0) {
1210                 init_tel_txopt(&opt, encap_limit);
1211                 ipv6_push_frag_opts(skb, &opt.ops, &proto);
1212         }
1213
1214         skb_push(skb, sizeof(struct ipv6hdr));
1215         skb_reset_network_header(skb);
1216         ipv6h = ipv6_hdr(skb);
1217         ip6_flow_hdr(ipv6h, dsfield,
1218                      ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1219         ipv6h->hop_limit = hop_limit;
1220         ipv6h->nexthdr = proto;
1221         ipv6h->saddr = fl6->saddr;
1222         ipv6h->daddr = fl6->daddr;
1223         ip6tunnel_xmit(NULL, skb, dev);
1224         return 0;
1225 tx_err_link_failure:
1226         stats->tx_carrier_errors++;
1227         dst_link_failure(skb);
1228 tx_err_dst_release:
1229         dst_release(dst);
1230         return err;
1231 }
1232 EXPORT_SYMBOL(ip6_tnl_xmit);
1233
1234 static inline int
1235 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1236 {
1237         struct ip6_tnl *t = netdev_priv(dev);
1238         const struct iphdr  *iph;
1239         int encap_limit = -1;
1240         struct flowi6 fl6;
1241         __u8 dsfield;
1242         __u32 mtu;
1243         u8 tproto;
1244         int err;
1245
1246         /* ensure we can access the full inner ip header */
1247         if (!pskb_may_pull(skb, sizeof(struct iphdr)))
1248                 return -1;
1249
1250         iph = ip_hdr(skb);
1251         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1252
1253         tproto = READ_ONCE(t->parms.proto);
1254         if (tproto != IPPROTO_IPIP && tproto != 0)
1255                 return -1;
1256
1257         if (t->parms.collect_md) {
1258                 struct ip_tunnel_info *tun_info;
1259                 const struct ip_tunnel_key *key;
1260
1261                 tun_info = skb_tunnel_info(skb);
1262                 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1263                              ip_tunnel_info_af(tun_info) != AF_INET6))
1264                         return -1;
1265                 key = &tun_info->key;
1266                 memset(&fl6, 0, sizeof(fl6));
1267                 fl6.flowi6_proto = IPPROTO_IPIP;
1268                 fl6.saddr = key->u.ipv6.src;
1269                 fl6.daddr = key->u.ipv6.dst;
1270                 fl6.flowlabel = key->label;
1271                 dsfield =  key->tos;
1272         } else {
1273                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1274                         encap_limit = t->parms.encap_limit;
1275
1276                 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1277                 fl6.flowi6_proto = IPPROTO_IPIP;
1278
1279                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1280                         dsfield = ipv4_get_dsfield(iph);
1281                 else
1282                         dsfield = ip6_tclass(t->parms.flowinfo);
1283                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1284                         fl6.flowi6_mark = skb->mark;
1285                 else
1286                         fl6.flowi6_mark = t->parms.fwmark;
1287         }
1288
1289         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1290
1291         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1292                 return -1;
1293
1294         dsfield = INET_ECN_encapsulate(dsfield, ipv4_get_dsfield(iph));
1295
1296         skb_set_inner_ipproto(skb, IPPROTO_IPIP);
1297
1298         err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1299                            IPPROTO_IPIP);
1300         if (err != 0) {
1301                 /* XXX: send ICMP error even if DF is not set. */
1302                 if (err == -EMSGSIZE)
1303                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1304                                   htonl(mtu));
1305                 return -1;
1306         }
1307
1308         return 0;
1309 }
1310
1311 static inline int
1312 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1313 {
1314         struct ip6_tnl *t = netdev_priv(dev);
1315         struct ipv6hdr *ipv6h;
1316         int encap_limit = -1;
1317         __u16 offset;
1318         struct flowi6 fl6;
1319         __u8 dsfield;
1320         __u32 mtu;
1321         u8 tproto;
1322         int err;
1323
1324         if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))
1325                 return -1;
1326
1327         ipv6h = ipv6_hdr(skb);
1328         tproto = READ_ONCE(t->parms.proto);
1329         if ((tproto != IPPROTO_IPV6 && tproto != 0) ||
1330             ip6_tnl_addr_conflict(t, ipv6h))
1331                 return -1;
1332
1333         if (t->parms.collect_md) {
1334                 struct ip_tunnel_info *tun_info;
1335                 const struct ip_tunnel_key *key;
1336
1337                 tun_info = skb_tunnel_info(skb);
1338                 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1339                              ip_tunnel_info_af(tun_info) != AF_INET6))
1340                         return -1;
1341                 key = &tun_info->key;
1342                 memset(&fl6, 0, sizeof(fl6));
1343                 fl6.flowi6_proto = IPPROTO_IPV6;
1344                 fl6.saddr = key->u.ipv6.src;
1345                 fl6.daddr = key->u.ipv6.dst;
1346                 fl6.flowlabel = key->label;
1347                 dsfield = key->tos;
1348         } else {
1349                 offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1350                 /* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
1351                 ipv6h = ipv6_hdr(skb);
1352                 if (offset > 0) {
1353                         struct ipv6_tlv_tnl_enc_lim *tel;
1354
1355                         tel = (void *)&skb_network_header(skb)[offset];
1356                         if (tel->encap_limit == 0) {
1357                                 icmpv6_send(skb, ICMPV6_PARAMPROB,
1358                                             ICMPV6_HDR_FIELD, offset + 2);
1359                                 return -1;
1360                         }
1361                         encap_limit = tel->encap_limit - 1;
1362                 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
1363                         encap_limit = t->parms.encap_limit;
1364                 }
1365
1366                 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1367                 fl6.flowi6_proto = IPPROTO_IPV6;
1368
1369                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1370                         dsfield = ipv6_get_dsfield(ipv6h);
1371                 else
1372                         dsfield = ip6_tclass(t->parms.flowinfo);
1373                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1374                         fl6.flowlabel |= ip6_flowlabel(ipv6h);
1375                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1376                         fl6.flowi6_mark = skb->mark;
1377                 else
1378                         fl6.flowi6_mark = t->parms.fwmark;
1379         }
1380
1381         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1382
1383         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1384                 return -1;
1385
1386         dsfield = INET_ECN_encapsulate(dsfield, ipv6_get_dsfield(ipv6h));
1387
1388         skb_set_inner_ipproto(skb, IPPROTO_IPV6);
1389
1390         err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1391                            IPPROTO_IPV6);
1392         if (err != 0) {
1393                 if (err == -EMSGSIZE)
1394                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1395                 return -1;
1396         }
1397
1398         return 0;
1399 }
1400
1401 static netdev_tx_t
1402 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1403 {
1404         struct ip6_tnl *t = netdev_priv(dev);
1405         struct net_device_stats *stats = &t->dev->stats;
1406         int ret;
1407
1408         switch (skb->protocol) {
1409         case htons(ETH_P_IP):
1410                 ret = ip4ip6_tnl_xmit(skb, dev);
1411                 break;
1412         case htons(ETH_P_IPV6):
1413                 ret = ip6ip6_tnl_xmit(skb, dev);
1414                 break;
1415         default:
1416                 goto tx_err;
1417         }
1418
1419         if (ret < 0)
1420                 goto tx_err;
1421
1422         return NETDEV_TX_OK;
1423
1424 tx_err:
1425         stats->tx_errors++;
1426         stats->tx_dropped++;
1427         kfree_skb(skb);
1428         return NETDEV_TX_OK;
1429 }
1430
1431 static void ip6_tnl_link_config(struct ip6_tnl *t)
1432 {
1433         struct net_device *dev = t->dev;
1434         struct __ip6_tnl_parm *p = &t->parms;
1435         struct flowi6 *fl6 = &t->fl.u.ip6;
1436         int t_hlen;
1437
1438         memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1439         memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1440
1441         /* Set up flowi template */
1442         fl6->saddr = p->laddr;
1443         fl6->daddr = p->raddr;
1444         fl6->flowi6_oif = p->link;
1445         fl6->flowlabel = 0;
1446
1447         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1448                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1449         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1450                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1451
1452         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1453         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1454
1455         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1456                 dev->flags |= IFF_POINTOPOINT;
1457         else
1458                 dev->flags &= ~IFF_POINTOPOINT;
1459
1460         t->tun_hlen = 0;
1461         t->hlen = t->encap_hlen + t->tun_hlen;
1462         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1463
1464         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1465                 int strict = (ipv6_addr_type(&p->raddr) &
1466                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1467
1468                 struct rt6_info *rt = rt6_lookup(t->net,
1469                                                  &p->raddr, &p->laddr,
1470                                                  p->link, NULL, strict);
1471
1472                 if (!rt)
1473                         return;
1474
1475                 if (rt->dst.dev) {
1476                         dev->hard_header_len = rt->dst.dev->hard_header_len +
1477                                 t_hlen;
1478
1479                         dev->mtu = rt->dst.dev->mtu - t_hlen;
1480                         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1481                                 dev->mtu -= 8;
1482
1483                         if (dev->mtu < IPV6_MIN_MTU)
1484                                 dev->mtu = IPV6_MIN_MTU;
1485                 }
1486                 ip6_rt_put(rt);
1487         }
1488 }
1489
1490 /**
1491  * ip6_tnl_change - update the tunnel parameters
1492  *   @t: tunnel to be changed
1493  *   @p: tunnel configuration parameters
1494  *
1495  * Description:
1496  *   ip6_tnl_change() updates the tunnel parameters
1497  **/
1498
1499 static int
1500 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1501 {
1502         t->parms.laddr = p->laddr;
1503         t->parms.raddr = p->raddr;
1504         t->parms.flags = p->flags;
1505         t->parms.hop_limit = p->hop_limit;
1506         t->parms.encap_limit = p->encap_limit;
1507         t->parms.flowinfo = p->flowinfo;
1508         t->parms.link = p->link;
1509         t->parms.proto = p->proto;
1510         t->parms.fwmark = p->fwmark;
1511         dst_cache_reset(&t->dst_cache);
1512         ip6_tnl_link_config(t);
1513         return 0;
1514 }
1515
1516 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1517 {
1518         struct net *net = t->net;
1519         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1520         int err;
1521
1522         ip6_tnl_unlink(ip6n, t);
1523         synchronize_net();
1524         err = ip6_tnl_change(t, p);
1525         ip6_tnl_link(ip6n, t);
1526         netdev_state_change(t->dev);
1527         return err;
1528 }
1529
1530 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1531 {
1532         /* for default tnl0 device allow to change only the proto */
1533         t->parms.proto = p->proto;
1534         netdev_state_change(t->dev);
1535         return 0;
1536 }
1537
1538 static void
1539 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1540 {
1541         p->laddr = u->laddr;
1542         p->raddr = u->raddr;
1543         p->flags = u->flags;
1544         p->hop_limit = u->hop_limit;
1545         p->encap_limit = u->encap_limit;
1546         p->flowinfo = u->flowinfo;
1547         p->link = u->link;
1548         p->proto = u->proto;
1549         memcpy(p->name, u->name, sizeof(u->name));
1550 }
1551
1552 static void
1553 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1554 {
1555         u->laddr = p->laddr;
1556         u->raddr = p->raddr;
1557         u->flags = p->flags;
1558         u->hop_limit = p->hop_limit;
1559         u->encap_limit = p->encap_limit;
1560         u->flowinfo = p->flowinfo;
1561         u->link = p->link;
1562         u->proto = p->proto;
1563         memcpy(u->name, p->name, sizeof(u->name));
1564 }
1565
1566 /**
1567  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1568  *   @dev: virtual device associated with tunnel
1569  *   @ifr: parameters passed from userspace
1570  *   @cmd: command to be performed
1571  *
1572  * Description:
1573  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1574  *   from userspace.
1575  *
1576  *   The possible commands are the following:
1577  *     %SIOCGETTUNNEL: get tunnel parameters for device
1578  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1579  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1580  *     %SIOCDELTUNNEL: delete tunnel
1581  *
1582  *   The fallback device "ip6tnl0", created during module
1583  *   initialization, can be used for creating other tunnel devices.
1584  *
1585  * Return:
1586  *   0 on success,
1587  *   %-EFAULT if unable to copy data to or from userspace,
1588  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1589  *   %-EINVAL if passed tunnel parameters are invalid,
1590  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1591  *   %-ENODEV if attempting to change or delete a nonexisting device
1592  **/
1593
1594 static int
1595 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1596 {
1597         int err = 0;
1598         struct ip6_tnl_parm p;
1599         struct __ip6_tnl_parm p1;
1600         struct ip6_tnl *t = netdev_priv(dev);
1601         struct net *net = t->net;
1602         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1603
1604         memset(&p1, 0, sizeof(p1));
1605
1606         switch (cmd) {
1607         case SIOCGETTUNNEL:
1608                 if (dev == ip6n->fb_tnl_dev) {
1609                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1610                                 err = -EFAULT;
1611                                 break;
1612                         }
1613                         ip6_tnl_parm_from_user(&p1, &p);
1614                         t = ip6_tnl_locate(net, &p1, 0);
1615                         if (IS_ERR(t))
1616                                 t = netdev_priv(dev);
1617                 } else {
1618                         memset(&p, 0, sizeof(p));
1619                 }
1620                 ip6_tnl_parm_to_user(&p, &t->parms);
1621                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1622                         err = -EFAULT;
1623                 }
1624                 break;
1625         case SIOCADDTUNNEL:
1626         case SIOCCHGTUNNEL:
1627                 err = -EPERM;
1628                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1629                         break;
1630                 err = -EFAULT;
1631                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1632                         break;
1633                 err = -EINVAL;
1634                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1635                     p.proto != 0)
1636                         break;
1637                 ip6_tnl_parm_from_user(&p1, &p);
1638                 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1639                 if (cmd == SIOCCHGTUNNEL) {
1640                         if (!IS_ERR(t)) {
1641                                 if (t->dev != dev) {
1642                                         err = -EEXIST;
1643                                         break;
1644                                 }
1645                         } else
1646                                 t = netdev_priv(dev);
1647                         if (dev == ip6n->fb_tnl_dev)
1648                                 err = ip6_tnl0_update(t, &p1);
1649                         else
1650                                 err = ip6_tnl_update(t, &p1);
1651                 }
1652                 if (!IS_ERR(t)) {
1653                         err = 0;
1654                         ip6_tnl_parm_to_user(&p, &t->parms);
1655                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1656                                 err = -EFAULT;
1657
1658                 } else {
1659                         err = PTR_ERR(t);
1660                 }
1661                 break;
1662         case SIOCDELTUNNEL:
1663                 err = -EPERM;
1664                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1665                         break;
1666
1667                 if (dev == ip6n->fb_tnl_dev) {
1668                         err = -EFAULT;
1669                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1670                                 break;
1671                         err = -ENOENT;
1672                         ip6_tnl_parm_from_user(&p1, &p);
1673                         t = ip6_tnl_locate(net, &p1, 0);
1674                         if (IS_ERR(t))
1675                                 break;
1676                         err = -EPERM;
1677                         if (t->dev == ip6n->fb_tnl_dev)
1678                                 break;
1679                         dev = t->dev;
1680                 }
1681                 err = 0;
1682                 unregister_netdevice(dev);
1683                 break;
1684         default:
1685                 err = -EINVAL;
1686         }
1687         return err;
1688 }
1689
1690 /**
1691  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1692  *   @dev: virtual device associated with tunnel
1693  *   @new_mtu: the new mtu
1694  *
1695  * Return:
1696  *   0 on success,
1697  *   %-EINVAL if mtu too small
1698  **/
1699
1700 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1701 {
1702         struct ip6_tnl *tnl = netdev_priv(dev);
1703
1704         if (tnl->parms.proto == IPPROTO_IPV6) {
1705                 if (new_mtu < IPV6_MIN_MTU)
1706                         return -EINVAL;
1707         } else {
1708                 if (new_mtu < ETH_MIN_MTU)
1709                         return -EINVAL;
1710         }
1711         if (tnl->parms.proto == IPPROTO_IPV6 || tnl->parms.proto == 0) {
1712                 if (new_mtu > IP6_MAX_MTU - dev->hard_header_len)
1713                         return -EINVAL;
1714         } else {
1715                 if (new_mtu > IP_MAX_MTU - dev->hard_header_len)
1716                         return -EINVAL;
1717         }
1718         dev->mtu = new_mtu;
1719         return 0;
1720 }
1721 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1722
1723 int ip6_tnl_get_iflink(const struct net_device *dev)
1724 {
1725         struct ip6_tnl *t = netdev_priv(dev);
1726
1727         return t->parms.link;
1728 }
1729 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1730
1731 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1732                           unsigned int num)
1733 {
1734         if (num >= MAX_IPTUN_ENCAP_OPS)
1735                 return -ERANGE;
1736
1737         return !cmpxchg((const struct ip6_tnl_encap_ops **)
1738                         &ip6tun_encaps[num],
1739                         NULL, ops) ? 0 : -1;
1740 }
1741 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1742
1743 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1744                           unsigned int num)
1745 {
1746         int ret;
1747
1748         if (num >= MAX_IPTUN_ENCAP_OPS)
1749                 return -ERANGE;
1750
1751         ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1752                        &ip6tun_encaps[num],
1753                        ops, NULL) == ops) ? 0 : -1;
1754
1755         synchronize_net();
1756
1757         return ret;
1758 }
1759 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1760
1761 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1762                         struct ip_tunnel_encap *ipencap)
1763 {
1764         int hlen;
1765
1766         memset(&t->encap, 0, sizeof(t->encap));
1767
1768         hlen = ip6_encap_hlen(ipencap);
1769         if (hlen < 0)
1770                 return hlen;
1771
1772         t->encap.type = ipencap->type;
1773         t->encap.sport = ipencap->sport;
1774         t->encap.dport = ipencap->dport;
1775         t->encap.flags = ipencap->flags;
1776
1777         t->encap_hlen = hlen;
1778         t->hlen = t->encap_hlen + t->tun_hlen;
1779
1780         return 0;
1781 }
1782 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1783
1784 static const struct net_device_ops ip6_tnl_netdev_ops = {
1785         .ndo_init       = ip6_tnl_dev_init,
1786         .ndo_uninit     = ip6_tnl_dev_uninit,
1787         .ndo_start_xmit = ip6_tnl_start_xmit,
1788         .ndo_do_ioctl   = ip6_tnl_ioctl,
1789         .ndo_change_mtu = ip6_tnl_change_mtu,
1790         .ndo_get_stats  = ip6_get_stats,
1791         .ndo_get_iflink = ip6_tnl_get_iflink,
1792 };
1793
1794 #define IPXIPX_FEATURES (NETIF_F_SG |           \
1795                          NETIF_F_FRAGLIST |     \
1796                          NETIF_F_HIGHDMA |      \
1797                          NETIF_F_GSO_SOFTWARE | \
1798                          NETIF_F_HW_CSUM)
1799
1800 /**
1801  * ip6_tnl_dev_setup - setup virtual tunnel device
1802  *   @dev: virtual device associated with tunnel
1803  *
1804  * Description:
1805  *   Initialize function pointers and device parameters
1806  **/
1807
1808 static void ip6_tnl_dev_setup(struct net_device *dev)
1809 {
1810         dev->netdev_ops = &ip6_tnl_netdev_ops;
1811         dev->needs_free_netdev = true;
1812         dev->priv_destructor = ip6_dev_free;
1813
1814         dev->type = ARPHRD_TUNNEL6;
1815         dev->flags |= IFF_NOARP;
1816         dev->addr_len = sizeof(struct in6_addr);
1817         dev->features |= NETIF_F_LLTX;
1818         netif_keep_dst(dev);
1819
1820         dev->features           |= IPXIPX_FEATURES;
1821         dev->hw_features        |= IPXIPX_FEATURES;
1822
1823         /* This perm addr will be used as interface identifier by IPv6 */
1824         dev->addr_assign_type = NET_ADDR_RANDOM;
1825         eth_random_addr(dev->perm_addr);
1826 }
1827
1828
1829 /**
1830  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1831  *   @dev: virtual device associated with tunnel
1832  **/
1833
1834 static inline int
1835 ip6_tnl_dev_init_gen(struct net_device *dev)
1836 {
1837         struct ip6_tnl *t = netdev_priv(dev);
1838         int ret;
1839         int t_hlen;
1840
1841         t->dev = dev;
1842         t->net = dev_net(dev);
1843         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1844         if (!dev->tstats)
1845                 return -ENOMEM;
1846
1847         ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1848         if (ret)
1849                 goto free_stats;
1850
1851         ret = gro_cells_init(&t->gro_cells, dev);
1852         if (ret)
1853                 goto destroy_dst;
1854
1855         t->tun_hlen = 0;
1856         t->hlen = t->encap_hlen + t->tun_hlen;
1857         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1858
1859         dev->type = ARPHRD_TUNNEL6;
1860         dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1861         dev->mtu = ETH_DATA_LEN - t_hlen;
1862         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1863                 dev->mtu -= 8;
1864         dev->min_mtu = ETH_MIN_MTU;
1865         dev->max_mtu = IP6_MAX_MTU - dev->hard_header_len;
1866
1867         return 0;
1868
1869 destroy_dst:
1870         dst_cache_destroy(&t->dst_cache);
1871 free_stats:
1872         free_percpu(dev->tstats);
1873         dev->tstats = NULL;
1874
1875         return ret;
1876 }
1877
1878 /**
1879  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1880  *   @dev: virtual device associated with tunnel
1881  **/
1882
1883 static int ip6_tnl_dev_init(struct net_device *dev)
1884 {
1885         struct ip6_tnl *t = netdev_priv(dev);
1886         int err = ip6_tnl_dev_init_gen(dev);
1887
1888         if (err)
1889                 return err;
1890         ip6_tnl_link_config(t);
1891         if (t->parms.collect_md) {
1892                 dev->features |= NETIF_F_NETNS_LOCAL;
1893                 netif_keep_dst(dev);
1894         }
1895         return 0;
1896 }
1897
1898 /**
1899  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1900  *   @dev: fallback device
1901  *
1902  * Return: 0
1903  **/
1904
1905 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1906 {
1907         struct ip6_tnl *t = netdev_priv(dev);
1908         struct net *net = dev_net(dev);
1909         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1910
1911         t->parms.proto = IPPROTO_IPV6;
1912         dev_hold(dev);
1913
1914         rcu_assign_pointer(ip6n->tnls_wc[0], t);
1915         return 0;
1916 }
1917
1918 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[],
1919                             struct netlink_ext_ack *extack)
1920 {
1921         u8 proto;
1922
1923         if (!data || !data[IFLA_IPTUN_PROTO])
1924                 return 0;
1925
1926         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1927         if (proto != IPPROTO_IPV6 &&
1928             proto != IPPROTO_IPIP &&
1929             proto != 0)
1930                 return -EINVAL;
1931
1932         return 0;
1933 }
1934
1935 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1936                                   struct __ip6_tnl_parm *parms)
1937 {
1938         memset(parms, 0, sizeof(*parms));
1939
1940         if (!data)
1941                 return;
1942
1943         if (data[IFLA_IPTUN_LINK])
1944                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1945
1946         if (data[IFLA_IPTUN_LOCAL])
1947                 parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1948
1949         if (data[IFLA_IPTUN_REMOTE])
1950                 parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1951
1952         if (data[IFLA_IPTUN_TTL])
1953                 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1954
1955         if (data[IFLA_IPTUN_ENCAP_LIMIT])
1956                 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1957
1958         if (data[IFLA_IPTUN_FLOWINFO])
1959                 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1960
1961         if (data[IFLA_IPTUN_FLAGS])
1962                 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1963
1964         if (data[IFLA_IPTUN_PROTO])
1965                 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1966
1967         if (data[IFLA_IPTUN_COLLECT_METADATA])
1968                 parms->collect_md = true;
1969
1970         if (data[IFLA_IPTUN_FWMARK])
1971                 parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1972 }
1973
1974 static bool ip6_tnl_netlink_encap_parms(struct nlattr *data[],
1975                                         struct ip_tunnel_encap *ipencap)
1976 {
1977         bool ret = false;
1978
1979         memset(ipencap, 0, sizeof(*ipencap));
1980
1981         if (!data)
1982                 return ret;
1983
1984         if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1985                 ret = true;
1986                 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1987         }
1988
1989         if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1990                 ret = true;
1991                 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1992         }
1993
1994         if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1995                 ret = true;
1996                 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1997         }
1998
1999         if (data[IFLA_IPTUN_ENCAP_DPORT]) {
2000                 ret = true;
2001                 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
2002         }
2003
2004         return ret;
2005 }
2006
2007 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
2008                            struct nlattr *tb[], struct nlattr *data[],
2009                            struct netlink_ext_ack *extack)
2010 {
2011         struct net *net = dev_net(dev);
2012         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2013         struct ip_tunnel_encap ipencap;
2014         struct ip6_tnl *nt, *t;
2015         int err;
2016
2017         nt = netdev_priv(dev);
2018
2019         if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2020                 err = ip6_tnl_encap_setup(nt, &ipencap);
2021                 if (err < 0)
2022                         return err;
2023         }
2024
2025         ip6_tnl_netlink_parms(data, &nt->parms);
2026
2027         if (nt->parms.collect_md) {
2028                 if (rtnl_dereference(ip6n->collect_md_tun))
2029                         return -EEXIST;
2030         } else {
2031                 t = ip6_tnl_locate(net, &nt->parms, 0);
2032                 if (!IS_ERR(t))
2033                         return -EEXIST;
2034         }
2035
2036         err = ip6_tnl_create2(dev);
2037         if (!err && tb[IFLA_MTU])
2038                 ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
2039
2040         return err;
2041 }
2042
2043 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
2044                               struct nlattr *data[],
2045                               struct netlink_ext_ack *extack)
2046 {
2047         struct ip6_tnl *t = netdev_priv(dev);
2048         struct __ip6_tnl_parm p;
2049         struct net *net = t->net;
2050         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2051         struct ip_tunnel_encap ipencap;
2052
2053         if (dev == ip6n->fb_tnl_dev)
2054                 return -EINVAL;
2055
2056         if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2057                 int err = ip6_tnl_encap_setup(t, &ipencap);
2058
2059                 if (err < 0)
2060                         return err;
2061         }
2062         ip6_tnl_netlink_parms(data, &p);
2063         if (p.collect_md)
2064                 return -EINVAL;
2065
2066         t = ip6_tnl_locate(net, &p, 0);
2067         if (!IS_ERR(t)) {
2068                 if (t->dev != dev)
2069                         return -EEXIST;
2070         } else
2071                 t = netdev_priv(dev);
2072
2073         return ip6_tnl_update(t, &p);
2074 }
2075
2076 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2077 {
2078         struct net *net = dev_net(dev);
2079         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2080
2081         if (dev != ip6n->fb_tnl_dev)
2082                 unregister_netdevice_queue(dev, head);
2083 }
2084
2085 static size_t ip6_tnl_get_size(const struct net_device *dev)
2086 {
2087         return
2088                 /* IFLA_IPTUN_LINK */
2089                 nla_total_size(4) +
2090                 /* IFLA_IPTUN_LOCAL */
2091                 nla_total_size(sizeof(struct in6_addr)) +
2092                 /* IFLA_IPTUN_REMOTE */
2093                 nla_total_size(sizeof(struct in6_addr)) +
2094                 /* IFLA_IPTUN_TTL */
2095                 nla_total_size(1) +
2096                 /* IFLA_IPTUN_ENCAP_LIMIT */
2097                 nla_total_size(1) +
2098                 /* IFLA_IPTUN_FLOWINFO */
2099                 nla_total_size(4) +
2100                 /* IFLA_IPTUN_FLAGS */
2101                 nla_total_size(4) +
2102                 /* IFLA_IPTUN_PROTO */
2103                 nla_total_size(1) +
2104                 /* IFLA_IPTUN_ENCAP_TYPE */
2105                 nla_total_size(2) +
2106                 /* IFLA_IPTUN_ENCAP_FLAGS */
2107                 nla_total_size(2) +
2108                 /* IFLA_IPTUN_ENCAP_SPORT */
2109                 nla_total_size(2) +
2110                 /* IFLA_IPTUN_ENCAP_DPORT */
2111                 nla_total_size(2) +
2112                 /* IFLA_IPTUN_COLLECT_METADATA */
2113                 nla_total_size(0) +
2114                 /* IFLA_IPTUN_FWMARK */
2115                 nla_total_size(4) +
2116                 0;
2117 }
2118
2119 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2120 {
2121         struct ip6_tnl *tunnel = netdev_priv(dev);
2122         struct __ip6_tnl_parm *parm = &tunnel->parms;
2123
2124         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2125             nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2126             nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2127             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2128             nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2129             nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2130             nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2131             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
2132             nla_put_u32(skb, IFLA_IPTUN_FWMARK, parm->fwmark))
2133                 goto nla_put_failure;
2134
2135         if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2136             nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2137             nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2138             nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2139                 goto nla_put_failure;
2140
2141         if (parm->collect_md)
2142                 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2143                         goto nla_put_failure;
2144
2145         return 0;
2146
2147 nla_put_failure:
2148         return -EMSGSIZE;
2149 }
2150
2151 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2152 {
2153         struct ip6_tnl *tunnel = netdev_priv(dev);
2154
2155         return tunnel->net;
2156 }
2157 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2158
2159 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2160         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
2161         [IFLA_IPTUN_LOCAL]              = { .len = sizeof(struct in6_addr) },
2162         [IFLA_IPTUN_REMOTE]             = { .len = sizeof(struct in6_addr) },
2163         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
2164         [IFLA_IPTUN_ENCAP_LIMIT]        = { .type = NLA_U8 },
2165         [IFLA_IPTUN_FLOWINFO]           = { .type = NLA_U32 },
2166         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U32 },
2167         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
2168         [IFLA_IPTUN_ENCAP_TYPE]         = { .type = NLA_U16 },
2169         [IFLA_IPTUN_ENCAP_FLAGS]        = { .type = NLA_U16 },
2170         [IFLA_IPTUN_ENCAP_SPORT]        = { .type = NLA_U16 },
2171         [IFLA_IPTUN_ENCAP_DPORT]        = { .type = NLA_U16 },
2172         [IFLA_IPTUN_COLLECT_METADATA]   = { .type = NLA_FLAG },
2173         [IFLA_IPTUN_FWMARK]             = { .type = NLA_U32 },
2174 };
2175
2176 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2177         .kind           = "ip6tnl",
2178         .maxtype        = IFLA_IPTUN_MAX,
2179         .policy         = ip6_tnl_policy,
2180         .priv_size      = sizeof(struct ip6_tnl),
2181         .setup          = ip6_tnl_dev_setup,
2182         .validate       = ip6_tnl_validate,
2183         .newlink        = ip6_tnl_newlink,
2184         .changelink     = ip6_tnl_changelink,
2185         .dellink        = ip6_tnl_dellink,
2186         .get_size       = ip6_tnl_get_size,
2187         .fill_info      = ip6_tnl_fill_info,
2188         .get_link_net   = ip6_tnl_get_link_net,
2189 };
2190
2191 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2192         .handler        = ip4ip6_rcv,
2193         .err_handler    = ip4ip6_err,
2194         .priority       =       1,
2195 };
2196
2197 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2198         .handler        = ip6ip6_rcv,
2199         .err_handler    = ip6ip6_err,
2200         .priority       =       1,
2201 };
2202
2203 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net, struct list_head *list)
2204 {
2205         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2206         struct net_device *dev, *aux;
2207         int h;
2208         struct ip6_tnl *t;
2209
2210         for_each_netdev_safe(net, dev, aux)
2211                 if (dev->rtnl_link_ops == &ip6_link_ops)
2212                         unregister_netdevice_queue(dev, list);
2213
2214         for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2215                 t = rtnl_dereference(ip6n->tnls_r_l[h]);
2216                 while (t) {
2217                         /* If dev is in the same netns, it has already
2218                          * been added to the list by the previous loop.
2219                          */
2220                         if (!net_eq(dev_net(t->dev), net))
2221                                 unregister_netdevice_queue(t->dev, list);
2222                         t = rtnl_dereference(t->next);
2223                 }
2224         }
2225 }
2226
2227 static int __net_init ip6_tnl_init_net(struct net *net)
2228 {
2229         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2230         struct ip6_tnl *t = NULL;
2231         int err;
2232
2233         ip6n->tnls[0] = ip6n->tnls_wc;
2234         ip6n->tnls[1] = ip6n->tnls_r_l;
2235
2236         if (!net_has_fallback_tunnels(net))
2237                 return 0;
2238         err = -ENOMEM;
2239         ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2240                                         NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2241
2242         if (!ip6n->fb_tnl_dev)
2243                 goto err_alloc_dev;
2244         dev_net_set(ip6n->fb_tnl_dev, net);
2245         ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2246         /* FB netdevice is special: we have one, and only one per netns.
2247          * Allowing to move it to another netns is clearly unsafe.
2248          */
2249         ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2250
2251         err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2252         if (err < 0)
2253                 goto err_register;
2254
2255         err = register_netdev(ip6n->fb_tnl_dev);
2256         if (err < 0)
2257                 goto err_register;
2258
2259         t = netdev_priv(ip6n->fb_tnl_dev);
2260
2261         strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2262         return 0;
2263
2264 err_register:
2265         free_netdev(ip6n->fb_tnl_dev);
2266 err_alloc_dev:
2267         return err;
2268 }
2269
2270 static void __net_exit ip6_tnl_exit_batch_net(struct list_head *net_list)
2271 {
2272         struct net *net;
2273         LIST_HEAD(list);
2274
2275         rtnl_lock();
2276         list_for_each_entry(net, net_list, exit_list)
2277                 ip6_tnl_destroy_tunnels(net, &list);
2278         unregister_netdevice_many(&list);
2279         rtnl_unlock();
2280 }
2281
2282 static struct pernet_operations ip6_tnl_net_ops = {
2283         .init = ip6_tnl_init_net,
2284         .exit_batch = ip6_tnl_exit_batch_net,
2285         .id   = &ip6_tnl_net_id,
2286         .size = sizeof(struct ip6_tnl_net),
2287 };
2288
2289 /**
2290  * ip6_tunnel_init - register protocol and reserve needed resources
2291  *
2292  * Return: 0 on success
2293  **/
2294
2295 static int __init ip6_tunnel_init(void)
2296 {
2297         int  err;
2298
2299         if (!ipv6_mod_enabled())
2300                 return -EOPNOTSUPP;
2301
2302         err = register_pernet_device(&ip6_tnl_net_ops);
2303         if (err < 0)
2304                 goto out_pernet;
2305
2306         err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2307         if (err < 0) {
2308                 pr_err("%s: can't register ip4ip6\n", __func__);
2309                 goto out_ip4ip6;
2310         }
2311
2312         err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2313         if (err < 0) {
2314                 pr_err("%s: can't register ip6ip6\n", __func__);
2315                 goto out_ip6ip6;
2316         }
2317         err = rtnl_link_register(&ip6_link_ops);
2318         if (err < 0)
2319                 goto rtnl_link_failed;
2320
2321         return 0;
2322
2323 rtnl_link_failed:
2324         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2325 out_ip6ip6:
2326         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2327 out_ip4ip6:
2328         unregister_pernet_device(&ip6_tnl_net_ops);
2329 out_pernet:
2330         return err;
2331 }
2332
2333 /**
2334  * ip6_tunnel_cleanup - free resources and unregister protocol
2335  **/
2336
2337 static void __exit ip6_tunnel_cleanup(void)
2338 {
2339         rtnl_link_unregister(&ip6_link_ops);
2340         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2341                 pr_info("%s: can't deregister ip4ip6\n", __func__);
2342
2343         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2344                 pr_info("%s: can't deregister ip6ip6\n", __func__);
2345
2346         unregister_pernet_device(&ip6_tnl_net_ops);
2347 }
2348
2349 module_init(ip6_tunnel_init);
2350 module_exit(ip6_tunnel_cleanup);