git.rot13.org Git - linux/blob - net/ipv6/ip6_tunnel.c

   1 /*
   2  *      IPv6 tunneling device
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Ville Nuorvala          <vnuorval@tcs.hut.fi>
   7  *      Yasuyuki Kozakai        <kozakai@linux-ipv6.org>
   8  *
   9  *      Based on:
  10  *      linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
  11  *
  12  *      RFC 2473
  13  *
  14  *      This program is free software; you can redistribute it and/or
  15  *      modify it under the terms of the GNU General Public License
  16  *      as published by the Free Software Foundation; either version
  17  *      2 of the License, or (at your option) any later version.
  18  *
  19  */
  20
  21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  22
  23 #include <linux/module.h>
  24 #include <linux/capability.h>
  25 #include <linux/errno.h>
  26 #include <linux/types.h>
  27 #include <linux/sockios.h>
  28 #include <linux/icmp.h>
  29 #include <linux/if.h>
  30 #include <linux/in.h>
  31 #include <linux/ip.h>
  32 #include <linux/net.h>
  33 #include <linux/in6.h>
  34 #include <linux/netdevice.h>
  35 #include <linux/if_arp.h>
  36 #include <linux/icmpv6.h>
  37 #include <linux/init.h>
  38 #include <linux/route.h>
  39 #include <linux/rtnetlink.h>
  40 #include <linux/netfilter_ipv6.h>
  41 #include <linux/slab.h>
  42 #include <linux/hash.h>
  43 #include <linux/etherdevice.h>
  44
  45 #include <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 = -ENOMEM;
 301
 302         if (p->name[0])
 303                 strlcpy(name, p->name, IFNAMSIZ);
 304         else
 305                 sprintf(name, "ip6tnl%%d");
 306
 307         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 308                            ip6_tnl_dev_setup);
 309         if (!dev)
 310                 goto failed;
 311
 312         dev_net_set(dev, net);
 313
 314         t = netdev_priv(dev);
 315         t->parms = *p;
 316         t->net = dev_net(dev);
 317         err = ip6_tnl_create2(dev);
 318         if (err < 0)
 319                 goto failed_free;
 320
 321         return t;
 322
 323 failed_free:
 324         free_netdev(dev);
 325 failed:
 326         return ERR_PTR(err);
 327 }
 328
 329 /**
 330  * ip6_tnl_locate - find or create tunnel matching given parameters
 331  *   @p: tunnel parameters
 332  *   @create: != 0 if allowed to create new tunnel if no match found
 333  *
 334  * Description:
 335  *   ip6_tnl_locate() first tries to locate an existing tunnel
 336  *   based on @parms. If this is unsuccessful, but @create is set a new
 337  *   tunnel device is created and registered for use.
 338  *
 339  * Return:
 340  *   matching tunnel or error pointer
 341  **/
 342
 343 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
 344                 struct __ip6_tnl_parm *p, int create)
 345 {
 346         const struct in6_addr *remote = &p->raddr;
 347         const struct in6_addr *local = &p->laddr;
 348         struct ip6_tnl __rcu **tp;
 349         struct ip6_tnl *t;
 350         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 351
 352         for (tp = ip6_tnl_bucket(ip6n, p);
 353              (t = rtnl_dereference(*tp)) != NULL;
 354              tp = &t->next) {
 355                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 356                     ipv6_addr_equal(remote, &t->parms.raddr)) {
 357                         if (create)
 358                                 return ERR_PTR(-EEXIST);
 359
 360                         return t;
 361                 }
 362         }
 363         if (!create)
 364                 return ERR_PTR(-ENODEV);
 365         return ip6_tnl_create(net, p);
 366 }
 367
 368 /**
 369  * ip6_tnl_dev_uninit - tunnel device uninitializer
 370  *   @dev: the device to be destroyed
 371  *
 372  * Description:
 373  *   ip6_tnl_dev_uninit() removes tunnel from its list
 374  **/
 375
 376 static void
 377 ip6_tnl_dev_uninit(struct net_device *dev)
 378 {
 379         struct ip6_tnl *t = netdev_priv(dev);
 380         struct net *net = t->net;
 381         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 382
 383         if (dev == ip6n->fb_tnl_dev)
 384                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
 385         else
 386                 ip6_tnl_unlink(ip6n, t);
 387         dst_cache_reset(&t->dst_cache);
 388         dev_put(dev);
 389 }
 390
 391 /**
 392  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
 393  *   @skb: received socket buffer
 394  *
 395  * Return:
 396  *   0 if none was found,
 397  *   else index to encapsulation limit
 398  **/
 399
 400 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
 401 {
 402         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)raw;
 403         unsigned int nhoff = raw - skb->data;
 404         unsigned int off = nhoff + sizeof(*ipv6h);
 405         u8 next, nexthdr = ipv6h->nexthdr;
 406
 407         while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
 408                 struct ipv6_opt_hdr *hdr;
 409                 u16 optlen;
 410
 411                 if (!pskb_may_pull(skb, off + sizeof(*hdr)))
 412                         break;
 413
 414                 hdr = (struct ipv6_opt_hdr *)(skb->data + off);
 415                 if (nexthdr == NEXTHDR_FRAGMENT) {
 416                         struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
 417                         if (frag_hdr->frag_off)
 418                                 break;
 419                         optlen = 8;
 420                 } else if (nexthdr == NEXTHDR_AUTH) {
 421                         optlen = (hdr->hdrlen + 2) << 2;
 422                 } else {
 423                         optlen = ipv6_optlen(hdr);
 424                 }
 425                 /* cache hdr->nexthdr, since pskb_may_pull() might
 426                  * invalidate hdr
 427                  */
 428                 next = hdr->nexthdr;
 429                 if (nexthdr == NEXTHDR_DEST) {
 430                         u16 i = 2;
 431
 432                         /* Remember : hdr is no longer valid at this point. */
 433                         if (!pskb_may_pull(skb, off + optlen))
 434                                 break;
 435
 436                         while (1) {
 437                                 struct ipv6_tlv_tnl_enc_lim *tel;
 438
 439                                 /* No more room for encapsulation limit */
 440                                 if (i + sizeof(*tel) > optlen)
 441                                         break;
 442
 443                                 tel = (struct ipv6_tlv_tnl_enc_lim *)(skb->data + off + i);
 444                                 /* return index of option if found and valid */
 445                                 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
 446                                     tel->length == 1)
 447                                         return i + off - nhoff;
 448                                 /* else jump to next option */
 449                                 if (tel->type)
 450                                         i += tel->length + 2;
 451                                 else
 452                                         i++;
 453                         }
 454                 }
 455                 nexthdr = next;
 456                 off += optlen;
 457         }
 458         return 0;
 459 }
 460 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
 461
 462 /**
 463  * ip6_tnl_err - tunnel error handler
 464  *
 465  * Description:
 466  *   ip6_tnl_err() should handle errors in the tunnel according
 467  *   to the specifications in RFC 2473.
 468  **/
 469
 470 static int
 471 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
 472             u8 *type, u8 *code, int *msg, __u32 *info, int offset)
 473 {
 474         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 475         struct net *net = dev_net(skb->dev);
 476         u8 rel_type = ICMPV6_DEST_UNREACH;
 477         u8 rel_code = ICMPV6_ADDR_UNREACH;
 478         __u32 rel_info = 0;
 479         struct ip6_tnl *t;
 480         int err = -ENOENT;
 481         int rel_msg = 0;
 482         u8 tproto;
 483         __u16 len;
 484
 485         /* If the packet doesn't contain the original IPv6 header we are
 486            in trouble since we might need the source address for further
 487            processing of the error. */
 488
 489         rcu_read_lock();
 490         t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, &ipv6h->saddr);
 491         if (!t)
 492                 goto out;
 493
 494         tproto = READ_ONCE(t->parms.proto);
 495         if (tproto != ipproto && tproto != 0)
 496                 goto out;
 497
 498         err = 0;
 499
 500         switch (*type) {
 501                 struct ipv6_tlv_tnl_enc_lim *tel;
 502                 __u32 mtu, teli;
 503         case ICMPV6_DEST_UNREACH:
 504                 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
 505                                     t->parms.name);
 506                 rel_msg = 1;
 507                 break;
 508         case ICMPV6_TIME_EXCEED:
 509                 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
 510                         net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 511                                             t->parms.name);
 512                         rel_msg = 1;
 513                 }
 514                 break;
 515         case ICMPV6_PARAMPROB:
 516                 teli = 0;
 517                 if ((*code) == ICMPV6_HDR_FIELD)
 518                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 519
 520                 if (teli && teli == *info - 2) {
 521                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 522                         if (tel->encap_limit == 0) {
 523                                 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 524                                                     t->parms.name);
 525                                 rel_msg = 1;
 526                         }
 527                 } else {
 528                         net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 529                                             t->parms.name);
 530                 }
 531                 break;
 532         case ICMPV6_PKT_TOOBIG:
 533                 ip6_update_pmtu(skb, net, htonl(*info), 0, 0,
 534                                 sock_net_uid(net, NULL));
 535                 mtu = *info - offset;
 536                 if (mtu < IPV6_MIN_MTU)
 537                         mtu = IPV6_MIN_MTU;
 538                 len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
 539                 if (len > mtu) {
 540                         rel_type = ICMPV6_PKT_TOOBIG;
 541                         rel_code = 0;
 542                         rel_info = mtu;
 543                         rel_msg = 1;
 544                 }
 545                 break;
 546         case NDISC_REDIRECT:
 547                 ip6_redirect(skb, net, skb->dev->ifindex, 0,
 548                              sock_net_uid(net, NULL));
 549                 break;
 550         }
 551
 552         *type = rel_type;
 553         *code = rel_code;
 554         *info = rel_info;
 555         *msg = rel_msg;
 556
 557 out:
 558         rcu_read_unlock();
 559         return err;
 560 }
 561
 562 static int
 563 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 564            u8 type, u8 code, int offset, __be32 info)
 565 {
 566         __u32 rel_info = ntohl(info);
 567         const struct iphdr *eiph;
 568         struct sk_buff *skb2;
 569         int err, rel_msg = 0;
 570         u8 rel_type = type;
 571         u8 rel_code = code;
 572         struct rtable *rt;
 573         struct flowi4 fl4;
 574
 575         err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
 576                           &rel_msg, &rel_info, offset);
 577         if (err < 0)
 578                 return err;
 579
 580         if (rel_msg == 0)
 581                 return 0;
 582
 583         switch (rel_type) {
 584         case ICMPV6_DEST_UNREACH:
 585                 if (rel_code != ICMPV6_ADDR_UNREACH)
 586                         return 0;
 587                 rel_type = ICMP_DEST_UNREACH;
 588                 rel_code = ICMP_HOST_UNREACH;
 589                 break;
 590         case ICMPV6_PKT_TOOBIG:
 591                 if (rel_code != 0)
 592                         return 0;
 593                 rel_type = ICMP_DEST_UNREACH;
 594                 rel_code = ICMP_FRAG_NEEDED;
 595                 break;
 596         default:
 597                 return 0;
 598         }
 599
 600         if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
 601                 return 0;
 602
 603         skb2 = skb_clone(skb, GFP_ATOMIC);
 604         if (!skb2)
 605                 return 0;
 606
 607         skb_dst_drop(skb2);
 608
 609         skb_pull(skb2, offset);
 610         skb_reset_network_header(skb2);
 611         eiph = ip_hdr(skb2);
 612
 613         /* Try to guess incoming interface */
 614         rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, eiph->saddr,
 615                                    0, 0, 0, IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 616         if (IS_ERR(rt))
 617                 goto out;
 618
 619         skb2->dev = rt->dst.dev;
 620         ip_rt_put(rt);
 621
 622         /* route "incoming" packet */
 623         if (rt->rt_flags & RTCF_LOCAL) {
 624                 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 625                                            eiph->daddr, eiph->saddr, 0, 0,
 626                                            IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 627                 if (IS_ERR(rt) || rt->dst.dev->type != ARPHRD_TUNNEL) {
 628                         if (!IS_ERR(rt))
 629                                 ip_rt_put(rt);
 630                         goto out;
 631                 }
 632                 skb_dst_set(skb2, &rt->dst);
 633         } else {
 634                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
 635                                    skb2->dev) ||
 636                     skb_dst(skb2)->dev->type != ARPHRD_TUNNEL)
 637                         goto out;
 638         }
 639
 640         /* change mtu on this route */
 641         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
 642                 if (rel_info > dst_mtu(skb_dst(skb2)))
 643                         goto out;
 644
 645                 skb_dst_update_pmtu(skb2, rel_info);
 646         }
 647
 648         icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
 649
 650 out:
 651         kfree_skb(skb2);
 652         return 0;
 653 }
 654
 655 static int
 656 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 657            u8 type, u8 code, int offset, __be32 info)
 658 {
 659         __u32 rel_info = ntohl(info);
 660         int err, rel_msg = 0;
 661         u8 rel_type = type;
 662         u8 rel_code = code;
 663
 664         err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
 665                           &rel_msg, &rel_info, offset);
 666         if (err < 0)
 667                 return err;
 668
 669         if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
 670                 struct rt6_info *rt;
 671                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 672
 673                 if (!skb2)
 674                         return 0;
 675
 676                 skb_dst_drop(skb2);
 677                 skb_pull(skb2, offset);
 678                 skb_reset_network_header(skb2);
 679
 680                 /* Try to guess incoming interface */
 681                 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
 682                                 NULL, 0, skb2, 0);
 683
 684                 if (rt && rt->dst.dev)
 685                         skb2->dev = rt->dst.dev;
 686
 687                 icmpv6_send(skb2, rel_type, rel_code, rel_info);
 688
 689                 ip6_rt_put(rt);
 690
 691                 kfree_skb(skb2);
 692         }
 693
 694         return 0;
 695 }
 696
 697 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 698                                        const struct ipv6hdr *ipv6h,
 699                                        struct sk_buff *skb)
 700 {
 701         __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
 702
 703         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 704                 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
 705
 706         return IP6_ECN_decapsulate(ipv6h, skb);
 707 }
 708
 709 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 710                                        const struct ipv6hdr *ipv6h,
 711                                        struct sk_buff *skb)
 712 {
 713         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 714                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
 715
 716         return IP6_ECN_decapsulate(ipv6h, skb);
 717 }
 718
 719 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
 720                              const struct in6_addr *laddr,
 721                              const struct in6_addr *raddr)
 722 {
 723         struct __ip6_tnl_parm *p = &t->parms;
 724         int ltype = ipv6_addr_type(laddr);
 725         int rtype = ipv6_addr_type(raddr);
 726         __u32 flags = 0;
 727
 728         if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
 729                 flags = IP6_TNL_F_CAP_PER_PACKET;
 730         } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 731                    rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 732                    !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
 733                    (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
 734                 if (ltype&IPV6_ADDR_UNICAST)
 735                         flags |= IP6_TNL_F_CAP_XMIT;
 736                 if (rtype&IPV6_ADDR_UNICAST)
 737                         flags |= IP6_TNL_F_CAP_RCV;
 738         }
 739         return flags;
 740 }
 741 EXPORT_SYMBOL(ip6_tnl_get_cap);
 742
 743 /* called with rcu_read_lock() */
 744 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
 745                                   const struct in6_addr *laddr,
 746                                   const struct in6_addr *raddr)
 747 {
 748         struct __ip6_tnl_parm *p = &t->parms;
 749         int ret = 0;
 750         struct net *net = t->net;
 751
 752         if ((p->flags & IP6_TNL_F_CAP_RCV) ||
 753             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
 754              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
 755                 struct net_device *ldev = NULL;
 756
 757                 if (p->link)
 758                         ldev = dev_get_by_index_rcu(net, p->link);
 759
 760                 if ((ipv6_addr_is_multicast(laddr) ||
 761                      likely(ipv6_chk_addr_and_flags(net, laddr, ldev, false,
 762                                                     0, IFA_F_TENTATIVE))) &&
 763                     ((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
 764                      likely(!ipv6_chk_addr_and_flags(net, raddr, ldev, true,
 765                                                      0, IFA_F_TENTATIVE))))
 766                         ret = 1;
 767         }
 768         return ret;
 769 }
 770 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
 771
 772 static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
 773                          const struct tnl_ptk_info *tpi,
 774                          struct metadata_dst *tun_dst,
 775                          int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 776                                                 const struct ipv6hdr *ipv6h,
 777                                                 struct sk_buff *skb),
 778                          bool log_ecn_err)
 779 {
 780         struct pcpu_sw_netstats *tstats;
 781         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 782         int err;
 783
 784         if ((!(tpi->flags & TUNNEL_CSUM) &&
 785              (tunnel->parms.i_flags & TUNNEL_CSUM)) ||
 786             ((tpi->flags & TUNNEL_CSUM) &&
 787              !(tunnel->parms.i_flags & TUNNEL_CSUM))) {
 788                 tunnel->dev->stats.rx_crc_errors++;
 789                 tunnel->dev->stats.rx_errors++;
 790                 goto drop;
 791         }
 792
 793         if (tunnel->parms.i_flags & TUNNEL_SEQ) {
 794                 if (!(tpi->flags & TUNNEL_SEQ) ||
 795                     (tunnel->i_seqno &&
 796                      (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
 797                         tunnel->dev->stats.rx_fifo_errors++;
 798                         tunnel->dev->stats.rx_errors++;
 799                         goto drop;
 800                 }
 801                 tunnel->i_seqno = ntohl(tpi->seq) + 1;
 802         }
 803
 804         skb->protocol = tpi->proto;
 805
 806         /* Warning: All skb pointers will be invalidated! */
 807         if (tunnel->dev->type == ARPHRD_ETHER) {
 808                 if (!pskb_may_pull(skb, ETH_HLEN)) {
 809                         tunnel->dev->stats.rx_length_errors++;
 810                         tunnel->dev->stats.rx_errors++;
 811                         goto drop;
 812                 }
 813
 814                 ipv6h = ipv6_hdr(skb);
 815                 skb->protocol = eth_type_trans(skb, tunnel->dev);
 816                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 817         } else {
 818                 skb->dev = tunnel->dev;
 819         }
 820
 821         skb_reset_network_header(skb);
 822         memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 823
 824         __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 825
 826         err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
 827         if (unlikely(err)) {
 828                 if (log_ecn_err)
 829                         net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
 830                                              &ipv6h->saddr,
 831                                              ipv6_get_dsfield(ipv6h));
 832                 if (err > 1) {
 833                         ++tunnel->dev->stats.rx_frame_errors;
 834                         ++tunnel->dev->stats.rx_errors;
 835                         goto drop;
 836                 }
 837         }
 838
 839         tstats = this_cpu_ptr(tunnel->dev->tstats);
 840         u64_stats_update_begin(&tstats->syncp);
 841         tstats->rx_packets++;
 842         tstats->rx_bytes += skb->len;
 843         u64_stats_update_end(&tstats->syncp);
 844
 845         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
 846
 847         if (tun_dst)
 848                 skb_dst_set(skb, (struct dst_entry *)tun_dst);
 849
 850         gro_cells_receive(&tunnel->gro_cells, skb);
 851         return 0;
 852
 853 drop:
 854         if (tun_dst)
 855                 dst_release((struct dst_entry *)tun_dst);
 856         kfree_skb(skb);
 857         return 0;
 858 }
 859
 860 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
 861                 const struct tnl_ptk_info *tpi,
 862                 struct metadata_dst *tun_dst,
 863                 bool log_ecn_err)
 864 {
 865         return __ip6_tnl_rcv(t, skb, tpi, tun_dst, ip6ip6_dscp_ecn_decapsulate,
 866                              log_ecn_err);
 867 }
 868 EXPORT_SYMBOL(ip6_tnl_rcv);
 869
 870 static const struct tnl_ptk_info tpi_v6 = {
 871         /* no tunnel info required for ipxip6. */
 872         .proto = htons(ETH_P_IPV6),
 873 };
 874
 875 static const struct tnl_ptk_info tpi_v4 = {
 876         /* no tunnel info required for ipxip6. */
 877         .proto = htons(ETH_P_IP),
 878 };
 879
 880 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
 881                       const struct tnl_ptk_info *tpi,
 882                       int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 883                                                   const struct ipv6hdr *ipv6h,
 884                                                   struct sk_buff *skb))
 885 {
 886         struct ip6_tnl *t;
 887         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 888         struct metadata_dst *tun_dst = NULL;
 889         int ret = -1;
 890
 891         rcu_read_lock();
 892         t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr);
 893
 894         if (t) {
 895                 u8 tproto = READ_ONCE(t->parms.proto);
 896
 897                 if (tproto != ipproto && tproto != 0)
 898                         goto drop;
 899                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 900                         goto drop;
 901                 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
 902                         goto drop;
 903                 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
 904                         goto drop;
 905                 if (t->parms.collect_md) {
 906                         tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
 907                         if (!tun_dst)
 908                                 goto drop;
 909                 }
 910                 ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
 911                                     log_ecn_error);
 912         }
 913
 914         rcu_read_unlock();
 915
 916         return ret;
 917
 918 drop:
 919         rcu_read_unlock();
 920         kfree_skb(skb);
 921         return 0;
 922 }
 923
 924 static int ip4ip6_rcv(struct sk_buff *skb)
 925 {
 926         return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
 927                           ip4ip6_dscp_ecn_decapsulate);
 928 }
 929
 930 static int ip6ip6_rcv(struct sk_buff *skb)
 931 {
 932         return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
 933                           ip6ip6_dscp_ecn_decapsulate);
 934 }
 935
 936 struct ipv6_tel_txoption {
 937         struct ipv6_txoptions ops;
 938         __u8 dst_opt[8];
 939 };
 940
 941 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 942 {
 943         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 944
 945         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 946         opt->dst_opt[3] = 1;
 947         opt->dst_opt[4] = encap_limit;
 948         opt->dst_opt[5] = IPV6_TLV_PADN;
 949         opt->dst_opt[6] = 1;
 950
 951         opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 952         opt->ops.opt_nflen = 8;
 953 }
 954
 955 /**
 956  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 957  *   @t: the outgoing tunnel device
 958  *   @hdr: IPv6 header from the incoming packet
 959  *
 960  * Description:
 961  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 962  *   doesn't match source of incoming packet.
 963  *
 964  * Return:
 965  *   1 if conflict,
 966  *   0 else
 967  **/
 968
 969 static inline bool
 970 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
 971 {
 972         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 973 }
 974
 975 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
 976                      const struct in6_addr *laddr,
 977                      const struct in6_addr *raddr)
 978 {
 979         struct __ip6_tnl_parm *p = &t->parms;
 980         int ret = 0;
 981         struct net *net = t->net;
 982
 983         if (t->parms.collect_md)
 984                 return 1;
 985
 986         if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
 987             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
 988              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
 989                 struct net_device *ldev = NULL;
 990
 991                 rcu_read_lock();
 992                 if (p->link)
 993                         ldev = dev_get_by_index_rcu(net, p->link);
 994
 995                 if (unlikely(!ipv6_chk_addr_and_flags(net, laddr, ldev, false,
 996                                                       0, IFA_F_TENTATIVE)))
 997                         pr_warn("%s xmit: Local address not yet configured!\n",
 998                                 p->name);
 999                 else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
1000                          !ipv6_addr_is_multicast(raddr) &&
1001                          unlikely(ipv6_chk_addr_and_flags(net, raddr, ldev,
1002                                                           true, 0, IFA_F_TENTATIVE)))
1003                         pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
1004                                 p->name);
1005                 else
1006                         ret = 1;
1007                 rcu_read_unlock();
1008         }
1009         return ret;
1010 }
1011 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1012
1013 /**
1014  * ip6_tnl_xmit - encapsulate packet and send
1015  *   @skb: the outgoing socket buffer
1016  *   @dev: the outgoing tunnel device
1017  *   @dsfield: dscp code for outer header
1018  *   @fl6: flow of tunneled packet
1019  *   @encap_limit: encapsulation limit
1020  *   @pmtu: Path MTU is stored if packet is too big
1021  *   @proto: next header value
1022  *
1023  * Description:
1024  *   Build new header and do some sanity checks on the packet before sending
1025  *   it.
1026  *
1027  * Return:
1028  *   0 on success
1029  *   -1 fail
1030  *   %-EMSGSIZE message too big. return mtu in this case.
1031  **/
1032
1033 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1034                  struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1035                  __u8 proto)
1036 {
1037         struct ip6_tnl *t = netdev_priv(dev);
1038         struct net *net = t->net;
1039         struct net_device_stats *stats = &t->dev->stats;
1040         struct ipv6hdr *ipv6h;
1041         struct ipv6_tel_txoption opt;
1042         struct dst_entry *dst = NULL, *ndst = NULL;
1043         struct net_device *tdev;
1044         int mtu;
1045         unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1046         unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1047         unsigned int max_headroom = psh_hlen;
1048         bool use_cache = false;
1049         u8 hop_limit;
1050         int err = -1;
1051
1052         if (t->parms.collect_md) {
1053                 hop_limit = skb_tunnel_info(skb)->key.ttl;
1054                 goto route_lookup;
1055         } else {
1056                 hop_limit = t->parms.hop_limit;
1057         }
1058
1059         /* NBMA tunnel */
1060         if (ipv6_addr_any(&t->parms.raddr)) {
1061                 if (skb->protocol == htons(ETH_P_IPV6)) {
1062                         struct in6_addr *addr6;
1063                         struct neighbour *neigh;
1064                         int addr_type;
1065
1066                         if (!skb_dst(skb))
1067                                 goto tx_err_link_failure;
1068
1069                         neigh = dst_neigh_lookup(skb_dst(skb),
1070                                                  &ipv6_hdr(skb)->daddr);
1071                         if (!neigh)
1072                                 goto tx_err_link_failure;
1073
1074                         addr6 = (struct in6_addr *)&neigh->primary_key;
1075                         addr_type = ipv6_addr_type(addr6);
1076
1077                         if (addr_type == IPV6_ADDR_ANY)
1078                                 addr6 = &ipv6_hdr(skb)->daddr;
1079
1080                         memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1081                         neigh_release(neigh);
1082                 }
1083         } else if (t->parms.proto != 0 && !(t->parms.flags &
1084                                             (IP6_TNL_F_USE_ORIG_TCLASS |
1085                                              IP6_TNL_F_USE_ORIG_FWMARK))) {
1086                 /* enable the cache only if neither the outer protocol nor the
1087                  * routing decision depends on the current inner header value
1088                  */
1089                 use_cache = true;
1090         }
1091
1092         if (use_cache)
1093                 dst = dst_cache_get(&t->dst_cache);
1094
1095         if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1096                 goto tx_err_link_failure;
1097
1098         if (!dst) {
1099 route_lookup:
1100                 /* add dsfield to flowlabel for route lookup */
1101                 fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1102
1103                 dst = ip6_route_output(net, NULL, fl6);
1104
1105                 if (dst->error)
1106                         goto tx_err_link_failure;
1107                 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1108                 if (IS_ERR(dst)) {
1109                         err = PTR_ERR(dst);
1110                         dst = NULL;
1111                         goto tx_err_link_failure;
1112                 }
1113                 if (t->parms.collect_md &&
1114                     ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1115                                        &fl6->daddr, 0, &fl6->saddr))
1116                         goto tx_err_link_failure;
1117                 ndst = dst;
1118         }
1119
1120         tdev = dst->dev;
1121
1122         if (tdev == dev) {
1123                 stats->collisions++;
1124                 net_warn_ratelimited("%s: Local routing loop detected!\n",
1125                                      t->parms.name);
1126                 goto tx_err_dst_release;
1127         }
1128         mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
1129         if (encap_limit >= 0) {
1130                 max_headroom += 8;
1131                 mtu -= 8;
1132         }
1133         if (skb->protocol == htons(ETH_P_IPV6)) {
1134                 if (mtu < IPV6_MIN_MTU)
1135                         mtu = IPV6_MIN_MTU;
1136         } else if (mtu < 576) {
1137                 mtu = 576;
1138         }
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 (encap_limit >= 0) {
1189                 init_tel_txopt(&opt, encap_limit);
1190                 ipv6_push_frag_opts(skb, &opt.ops, &proto);
1191         }
1192         hop_limit = hop_limit ? : ip6_dst_hoplimit(dst);
1193
1194         /* Calculate max headroom for all the headers and adjust
1195          * needed_headroom if necessary.
1196          */
1197         max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1198                         + dst->header_len + t->hlen;
1199         if (max_headroom > dev->needed_headroom)
1200                 dev->needed_headroom = max_headroom;
1201
1202         err = ip6_tnl_encap(skb, t, &proto, fl6);
1203         if (err)
1204                 return err;
1205
1206         skb_push(skb, sizeof(struct ipv6hdr));
1207         skb_reset_network_header(skb);
1208         ipv6h = ipv6_hdr(skb);
1209         ip6_flow_hdr(ipv6h, dsfield,
1210                      ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1211         ipv6h->hop_limit = hop_limit;
1212         ipv6h->nexthdr = proto;
1213         ipv6h->saddr = fl6->saddr;
1214         ipv6h->daddr = fl6->daddr;
1215         ip6tunnel_xmit(NULL, skb, dev);
1216         return 0;
1217 tx_err_link_failure:
1218         stats->tx_carrier_errors++;
1219         dst_link_failure(skb);
1220 tx_err_dst_release:
1221         dst_release(dst);
1222         return err;
1223 }
1224 EXPORT_SYMBOL(ip6_tnl_xmit);
1225
1226 static inline int
1227 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1228 {
1229         struct ip6_tnl *t = netdev_priv(dev);
1230         const struct iphdr  *iph = ip_hdr(skb);
1231         int encap_limit = -1;
1232         struct flowi6 fl6;
1233         __u8 dsfield;
1234         __u32 mtu;
1235         u8 tproto;
1236         int err;
1237
1238         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1239
1240         tproto = READ_ONCE(t->parms.proto);
1241         if (tproto != IPPROTO_IPIP && tproto != 0)
1242                 return -1;
1243
1244         if (t->parms.collect_md) {
1245                 struct ip_tunnel_info *tun_info;
1246                 const struct ip_tunnel_key *key;
1247
1248                 tun_info = skb_tunnel_info(skb);
1249                 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1250                              ip_tunnel_info_af(tun_info) != AF_INET6))
1251                         return -1;
1252                 key = &tun_info->key;
1253                 memset(&fl6, 0, sizeof(fl6));
1254                 fl6.flowi6_proto = IPPROTO_IPIP;
1255                 fl6.daddr = key->u.ipv6.dst;
1256                 fl6.flowlabel = key->label;
1257                 dsfield =  key->tos;
1258         } else {
1259                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1260                         encap_limit = t->parms.encap_limit;
1261
1262                 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1263                 fl6.flowi6_proto = IPPROTO_IPIP;
1264
1265                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1266                         dsfield = ipv4_get_dsfield(iph);
1267                 else
1268                         dsfield = ip6_tclass(t->parms.flowinfo);
1269                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1270                         fl6.flowi6_mark = skb->mark;
1271                 else
1272                         fl6.flowi6_mark = t->parms.fwmark;
1273         }
1274
1275         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1276
1277         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1278                 return -1;
1279
1280         dsfield = INET_ECN_encapsulate(dsfield, ipv4_get_dsfield(iph));
1281
1282         skb_set_inner_ipproto(skb, IPPROTO_IPIP);
1283
1284         err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1285                            IPPROTO_IPIP);
1286         if (err != 0) {
1287                 /* XXX: send ICMP error even if DF is not set. */
1288                 if (err == -EMSGSIZE)
1289                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1290                                   htonl(mtu));
1291                 return -1;
1292         }
1293
1294         return 0;
1295 }
1296
1297 static inline int
1298 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1299 {
1300         struct ip6_tnl *t = netdev_priv(dev);
1301         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
1302         int encap_limit = -1;
1303         __u16 offset;
1304         struct flowi6 fl6;
1305         __u8 dsfield;
1306         __u32 mtu;
1307         u8 tproto;
1308         int err;
1309
1310         tproto = READ_ONCE(t->parms.proto);
1311         if ((tproto != IPPROTO_IPV6 && tproto != 0) ||
1312             ip6_tnl_addr_conflict(t, ipv6h))
1313                 return -1;
1314
1315         if (t->parms.collect_md) {
1316                 struct ip_tunnel_info *tun_info;
1317                 const struct ip_tunnel_key *key;
1318
1319                 tun_info = skb_tunnel_info(skb);
1320                 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1321                              ip_tunnel_info_af(tun_info) != AF_INET6))
1322                         return -1;
1323                 key = &tun_info->key;
1324                 memset(&fl6, 0, sizeof(fl6));
1325                 fl6.flowi6_proto = IPPROTO_IPV6;
1326                 fl6.daddr = key->u.ipv6.dst;
1327                 fl6.flowlabel = key->label;
1328                 dsfield = key->tos;
1329         } else {
1330                 offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1331                 /* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
1332                 ipv6h = ipv6_hdr(skb);
1333                 if (offset > 0) {
1334                         struct ipv6_tlv_tnl_enc_lim *tel;
1335
1336                         tel = (void *)&skb_network_header(skb)[offset];
1337                         if (tel->encap_limit == 0) {
1338                                 icmpv6_send(skb, ICMPV6_PARAMPROB,
1339                                             ICMPV6_HDR_FIELD, offset + 2);
1340                                 return -1;
1341                         }
1342                         encap_limit = tel->encap_limit - 1;
1343                 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
1344                         encap_limit = t->parms.encap_limit;
1345                 }
1346
1347                 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1348                 fl6.flowi6_proto = IPPROTO_IPV6;
1349
1350                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1351                         dsfield = ipv6_get_dsfield(ipv6h);
1352                 else
1353                         dsfield = ip6_tclass(t->parms.flowinfo);
1354                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1355                         fl6.flowlabel |= ip6_flowlabel(ipv6h);
1356                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1357                         fl6.flowi6_mark = skb->mark;
1358                 else
1359                         fl6.flowi6_mark = t->parms.fwmark;
1360         }
1361
1362         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1363
1364         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1365                 return -1;
1366
1367         dsfield = INET_ECN_encapsulate(dsfield, ipv6_get_dsfield(ipv6h));
1368
1369         skb_set_inner_ipproto(skb, IPPROTO_IPV6);
1370
1371         err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1372                            IPPROTO_IPV6);
1373         if (err != 0) {
1374                 if (err == -EMSGSIZE)
1375                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1376                 return -1;
1377         }
1378
1379         return 0;
1380 }
1381
1382 static netdev_tx_t
1383 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1384 {
1385         struct ip6_tnl *t = netdev_priv(dev);
1386         struct net_device_stats *stats = &t->dev->stats;
1387         int ret;
1388
1389         switch (skb->protocol) {
1390         case htons(ETH_P_IP):
1391                 ret = ip4ip6_tnl_xmit(skb, dev);
1392                 break;
1393         case htons(ETH_P_IPV6):
1394                 ret = ip6ip6_tnl_xmit(skb, dev);
1395                 break;
1396         default:
1397                 goto tx_err;
1398         }
1399
1400         if (ret < 0)
1401                 goto tx_err;
1402
1403         return NETDEV_TX_OK;
1404
1405 tx_err:
1406         stats->tx_errors++;
1407         stats->tx_dropped++;
1408         kfree_skb(skb);
1409         return NETDEV_TX_OK;
1410 }
1411
1412 static void ip6_tnl_link_config(struct ip6_tnl *t)
1413 {
1414         struct net_device *dev = t->dev;
1415         struct __ip6_tnl_parm *p = &t->parms;
1416         struct flowi6 *fl6 = &t->fl.u.ip6;
1417         int t_hlen;
1418
1419         memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1420         memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1421
1422         /* Set up flowi template */
1423         fl6->saddr = p->laddr;
1424         fl6->daddr = p->raddr;
1425         fl6->flowi6_oif = p->link;
1426         fl6->flowlabel = 0;
1427
1428         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1429                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1430         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1431                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1432
1433         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1434         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1435
1436         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1437                 dev->flags |= IFF_POINTOPOINT;
1438         else
1439                 dev->flags &= ~IFF_POINTOPOINT;
1440
1441         t->tun_hlen = 0;
1442         t->hlen = t->encap_hlen + t->tun_hlen;
1443         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1444
1445         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1446                 int strict = (ipv6_addr_type(&p->raddr) &
1447                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1448
1449                 struct rt6_info *rt = rt6_lookup(t->net,
1450                                                  &p->raddr, &p->laddr,
1451                                                  p->link, NULL, strict);
1452
1453                 if (!rt)
1454                         return;
1455
1456                 if (rt->dst.dev) {
1457                         dev->hard_header_len = rt->dst.dev->hard_header_len +
1458                                 t_hlen;
1459
1460                         dev->mtu = rt->dst.dev->mtu - t_hlen;
1461                         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1462                                 dev->mtu -= 8;
1463
1464                         if (dev->mtu < IPV6_MIN_MTU)
1465                                 dev->mtu = IPV6_MIN_MTU;
1466                 }
1467                 ip6_rt_put(rt);
1468         }
1469 }
1470
1471 /**
1472  * ip6_tnl_change - update the tunnel parameters
1473  *   @t: tunnel to be changed
1474  *   @p: tunnel configuration parameters
1475  *
1476  * Description:
1477  *   ip6_tnl_change() updates the tunnel parameters
1478  **/
1479
1480 static int
1481 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1482 {
1483         t->parms.laddr = p->laddr;
1484         t->parms.raddr = p->raddr;
1485         t->parms.flags = p->flags;
1486         t->parms.hop_limit = p->hop_limit;
1487         t->parms.encap_limit = p->encap_limit;
1488         t->parms.flowinfo = p->flowinfo;
1489         t->parms.link = p->link;
1490         t->parms.proto = p->proto;
1491         t->parms.fwmark = p->fwmark;
1492         dst_cache_reset(&t->dst_cache);
1493         ip6_tnl_link_config(t);
1494         return 0;
1495 }
1496
1497 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1498 {
1499         struct net *net = t->net;
1500         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1501         int err;
1502
1503         ip6_tnl_unlink(ip6n, t);
1504         synchronize_net();
1505         err = ip6_tnl_change(t, p);
1506         ip6_tnl_link(ip6n, t);
1507         netdev_state_change(t->dev);
1508         return err;
1509 }
1510
1511 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1512 {
1513         /* for default tnl0 device allow to change only the proto */
1514         t->parms.proto = p->proto;
1515         netdev_state_change(t->dev);
1516         return 0;
1517 }
1518
1519 static void
1520 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1521 {
1522         p->laddr = u->laddr;
1523         p->raddr = u->raddr;
1524         p->flags = u->flags;
1525         p->hop_limit = u->hop_limit;
1526         p->encap_limit = u->encap_limit;
1527         p->flowinfo = u->flowinfo;
1528         p->link = u->link;
1529         p->proto = u->proto;
1530         memcpy(p->name, u->name, sizeof(u->name));
1531 }
1532
1533 static void
1534 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1535 {
1536         u->laddr = p->laddr;
1537         u->raddr = p->raddr;
1538         u->flags = p->flags;
1539         u->hop_limit = p->hop_limit;
1540         u->encap_limit = p->encap_limit;
1541         u->flowinfo = p->flowinfo;
1542         u->link = p->link;
1543         u->proto = p->proto;
1544         memcpy(u->name, p->name, sizeof(u->name));
1545 }
1546
1547 /**
1548  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1549  *   @dev: virtual device associated with tunnel
1550  *   @ifr: parameters passed from userspace
1551  *   @cmd: command to be performed
1552  *
1553  * Description:
1554  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1555  *   from userspace.
1556  *
1557  *   The possible commands are the following:
1558  *     %SIOCGETTUNNEL: get tunnel parameters for device
1559  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1560  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1561  *     %SIOCDELTUNNEL: delete tunnel
1562  *
1563  *   The fallback device "ip6tnl0", created during module
1564  *   initialization, can be used for creating other tunnel devices.
1565  *
1566  * Return:
1567  *   0 on success,
1568  *   %-EFAULT if unable to copy data to or from userspace,
1569  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1570  *   %-EINVAL if passed tunnel parameters are invalid,
1571  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1572  *   %-ENODEV if attempting to change or delete a nonexisting device
1573  **/
1574
1575 static int
1576 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1577 {
1578         int err = 0;
1579         struct ip6_tnl_parm p;
1580         struct __ip6_tnl_parm p1;
1581         struct ip6_tnl *t = netdev_priv(dev);
1582         struct net *net = t->net;
1583         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1584
1585         memset(&p1, 0, sizeof(p1));
1586
1587         switch (cmd) {
1588         case SIOCGETTUNNEL:
1589                 if (dev == ip6n->fb_tnl_dev) {
1590                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1591                                 err = -EFAULT;
1592                                 break;
1593                         }
1594                         ip6_tnl_parm_from_user(&p1, &p);
1595                         t = ip6_tnl_locate(net, &p1, 0);
1596                         if (IS_ERR(t))
1597                                 t = netdev_priv(dev);
1598                 } else {
1599                         memset(&p, 0, sizeof(p));
1600                 }
1601                 ip6_tnl_parm_to_user(&p, &t->parms);
1602                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1603                         err = -EFAULT;
1604                 }
1605                 break;
1606         case SIOCADDTUNNEL:
1607         case SIOCCHGTUNNEL:
1608                 err = -EPERM;
1609                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1610                         break;
1611                 err = -EFAULT;
1612                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1613                         break;
1614                 err = -EINVAL;
1615                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1616                     p.proto != 0)
1617                         break;
1618                 ip6_tnl_parm_from_user(&p1, &p);
1619                 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1620                 if (cmd == SIOCCHGTUNNEL) {
1621                         if (!IS_ERR(t)) {
1622                                 if (t->dev != dev) {
1623                                         err = -EEXIST;
1624                                         break;
1625                                 }
1626                         } else
1627                                 t = netdev_priv(dev);
1628                         if (dev == ip6n->fb_tnl_dev)
1629                                 err = ip6_tnl0_update(t, &p1);
1630                         else
1631                                 err = ip6_tnl_update(t, &p1);
1632                 }
1633                 if (!IS_ERR(t)) {
1634                         err = 0;
1635                         ip6_tnl_parm_to_user(&p, &t->parms);
1636                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1637                                 err = -EFAULT;
1638
1639                 } else {
1640                         err = PTR_ERR(t);
1641                 }
1642                 break;
1643         case SIOCDELTUNNEL:
1644                 err = -EPERM;
1645                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1646                         break;
1647
1648                 if (dev == ip6n->fb_tnl_dev) {
1649                         err = -EFAULT;
1650                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1651                                 break;
1652                         err = -ENOENT;
1653                         ip6_tnl_parm_from_user(&p1, &p);
1654                         t = ip6_tnl_locate(net, &p1, 0);
1655                         if (IS_ERR(t))
1656                                 break;
1657                         err = -EPERM;
1658                         if (t->dev == ip6n->fb_tnl_dev)
1659                                 break;
1660                         dev = t->dev;
1661                 }
1662                 err = 0;
1663                 unregister_netdevice(dev);
1664                 break;
1665         default:
1666                 err = -EINVAL;
1667         }
1668         return err;
1669 }
1670
1671 /**
1672  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1673  *   @dev: virtual device associated with tunnel
1674  *   @new_mtu: the new mtu
1675  *
1676  * Return:
1677  *   0 on success,
1678  *   %-EINVAL if mtu too small
1679  **/
1680
1681 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1682 {
1683         struct ip6_tnl *tnl = netdev_priv(dev);
1684
1685         if (tnl->parms.proto == IPPROTO_IPV6) {
1686                 if (new_mtu < IPV6_MIN_MTU)
1687                         return -EINVAL;
1688         } else {
1689                 if (new_mtu < ETH_MIN_MTU)
1690                         return -EINVAL;
1691         }
1692         if (new_mtu > 0xFFF8 - dev->hard_header_len)
1693                 return -EINVAL;
1694         dev->mtu = new_mtu;
1695         return 0;
1696 }
1697 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1698
1699 int ip6_tnl_get_iflink(const struct net_device *dev)
1700 {
1701         struct ip6_tnl *t = netdev_priv(dev);
1702
1703         return t->parms.link;
1704 }
1705 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1706
1707 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1708                           unsigned int num)
1709 {
1710         if (num >= MAX_IPTUN_ENCAP_OPS)
1711                 return -ERANGE;
1712
1713         return !cmpxchg((const struct ip6_tnl_encap_ops **)
1714                         &ip6tun_encaps[num],
1715                         NULL, ops) ? 0 : -1;
1716 }
1717 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1718
1719 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1720                           unsigned int num)
1721 {
1722         int ret;
1723
1724         if (num >= MAX_IPTUN_ENCAP_OPS)
1725                 return -ERANGE;
1726
1727         ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1728                        &ip6tun_encaps[num],
1729                        ops, NULL) == ops) ? 0 : -1;
1730
1731         synchronize_net();
1732
1733         return ret;
1734 }
1735 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1736
1737 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1738                         struct ip_tunnel_encap *ipencap)
1739 {
1740         int hlen;
1741
1742         memset(&t->encap, 0, sizeof(t->encap));
1743
1744         hlen = ip6_encap_hlen(ipencap);
1745         if (hlen < 0)
1746                 return hlen;
1747
1748         t->encap.type = ipencap->type;
1749         t->encap.sport = ipencap->sport;
1750         t->encap.dport = ipencap->dport;
1751         t->encap.flags = ipencap->flags;
1752
1753         t->encap_hlen = hlen;
1754         t->hlen = t->encap_hlen + t->tun_hlen;
1755
1756         return 0;
1757 }
1758 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1759
1760 static const struct net_device_ops ip6_tnl_netdev_ops = {
1761         .ndo_init       = ip6_tnl_dev_init,
1762         .ndo_uninit     = ip6_tnl_dev_uninit,
1763         .ndo_start_xmit = ip6_tnl_start_xmit,
1764         .ndo_do_ioctl   = ip6_tnl_ioctl,
1765         .ndo_change_mtu = ip6_tnl_change_mtu,
1766         .ndo_get_stats  = ip6_get_stats,
1767         .ndo_get_iflink = ip6_tnl_get_iflink,
1768 };
1769
1770 #define IPXIPX_FEATURES (NETIF_F_SG |           \
1771                          NETIF_F_FRAGLIST |     \
1772                          NETIF_F_HIGHDMA |      \
1773                          NETIF_F_GSO_SOFTWARE | \
1774                          NETIF_F_HW_CSUM)
1775
1776 /**
1777  * ip6_tnl_dev_setup - setup virtual tunnel device
1778  *   @dev: virtual device associated with tunnel
1779  *
1780  * Description:
1781  *   Initialize function pointers and device parameters
1782  **/
1783
1784 static void ip6_tnl_dev_setup(struct net_device *dev)
1785 {
1786         dev->netdev_ops = &ip6_tnl_netdev_ops;
1787         dev->needs_free_netdev = true;
1788         dev->priv_destructor = ip6_dev_free;
1789
1790         dev->type = ARPHRD_TUNNEL6;
1791         dev->flags |= IFF_NOARP;
1792         dev->addr_len = sizeof(struct in6_addr);
1793         dev->features |= NETIF_F_LLTX;
1794         netif_keep_dst(dev);
1795
1796         dev->features           |= IPXIPX_FEATURES;
1797         dev->hw_features        |= IPXIPX_FEATURES;
1798
1799         /* This perm addr will be used as interface identifier by IPv6 */
1800         dev->addr_assign_type = NET_ADDR_RANDOM;
1801         eth_random_addr(dev->perm_addr);
1802 }
1803
1804
1805 /**
1806  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1807  *   @dev: virtual device associated with tunnel
1808  **/
1809
1810 static inline int
1811 ip6_tnl_dev_init_gen(struct net_device *dev)
1812 {
1813         struct ip6_tnl *t = netdev_priv(dev);
1814         int ret;
1815         int t_hlen;
1816
1817         t->dev = dev;
1818         t->net = dev_net(dev);
1819         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1820         if (!dev->tstats)
1821                 return -ENOMEM;
1822
1823         ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1824         if (ret)
1825                 goto free_stats;
1826
1827         ret = gro_cells_init(&t->gro_cells, dev);
1828         if (ret)
1829                 goto destroy_dst;
1830
1831         t->tun_hlen = 0;
1832         t->hlen = t->encap_hlen + t->tun_hlen;
1833         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1834
1835         dev->type = ARPHRD_TUNNEL6;
1836         dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1837         dev->mtu = ETH_DATA_LEN - t_hlen;
1838         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1839                 dev->mtu -= 8;
1840         dev->min_mtu = ETH_MIN_MTU;
1841         dev->max_mtu = 0xFFF8 - dev->hard_header_len;
1842
1843         return 0;
1844
1845 destroy_dst:
1846         dst_cache_destroy(&t->dst_cache);
1847 free_stats:
1848         free_percpu(dev->tstats);
1849         dev->tstats = NULL;
1850
1851         return ret;
1852 }
1853
1854 /**
1855  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1856  *   @dev: virtual device associated with tunnel
1857  **/
1858
1859 static int ip6_tnl_dev_init(struct net_device *dev)
1860 {
1861         struct ip6_tnl *t = netdev_priv(dev);
1862         int err = ip6_tnl_dev_init_gen(dev);
1863
1864         if (err)
1865                 return err;
1866         ip6_tnl_link_config(t);
1867         if (t->parms.collect_md) {
1868                 dev->features |= NETIF_F_NETNS_LOCAL;
1869                 netif_keep_dst(dev);
1870         }
1871         return 0;
1872 }
1873
1874 /**
1875  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1876  *   @dev: fallback device
1877  *
1878  * Return: 0
1879  **/
1880
1881 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1882 {
1883         struct ip6_tnl *t = netdev_priv(dev);
1884         struct net *net = dev_net(dev);
1885         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1886
1887         t->parms.proto = IPPROTO_IPV6;
1888         dev_hold(dev);
1889
1890         rcu_assign_pointer(ip6n->tnls_wc[0], t);
1891         return 0;
1892 }
1893
1894 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[],
1895                             struct netlink_ext_ack *extack)
1896 {
1897         u8 proto;
1898
1899         if (!data || !data[IFLA_IPTUN_PROTO])
1900                 return 0;
1901
1902         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1903         if (proto != IPPROTO_IPV6 &&
1904             proto != IPPROTO_IPIP &&
1905             proto != 0)
1906                 return -EINVAL;
1907
1908         return 0;
1909 }
1910
1911 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1912                                   struct __ip6_tnl_parm *parms)
1913 {
1914         memset(parms, 0, sizeof(*parms));
1915
1916         if (!data)
1917                 return;
1918
1919         if (data[IFLA_IPTUN_LINK])
1920                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1921
1922         if (data[IFLA_IPTUN_LOCAL])
1923                 parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1924
1925         if (data[IFLA_IPTUN_REMOTE])
1926                 parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1927
1928         if (data[IFLA_IPTUN_TTL])
1929                 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1930
1931         if (data[IFLA_IPTUN_ENCAP_LIMIT])
1932                 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1933
1934         if (data[IFLA_IPTUN_FLOWINFO])
1935                 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1936
1937         if (data[IFLA_IPTUN_FLAGS])
1938                 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1939
1940         if (data[IFLA_IPTUN_PROTO])
1941                 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1942
1943         if (data[IFLA_IPTUN_COLLECT_METADATA])
1944                 parms->collect_md = true;
1945
1946         if (data[IFLA_IPTUN_FWMARK])
1947                 parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1948 }
1949
1950 static bool ip6_tnl_netlink_encap_parms(struct nlattr *data[],
1951                                         struct ip_tunnel_encap *ipencap)
1952 {
1953         bool ret = false;
1954
1955         memset(ipencap, 0, sizeof(*ipencap));
1956
1957         if (!data)
1958                 return ret;
1959
1960         if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1961                 ret = true;
1962                 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1963         }
1964
1965         if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1966                 ret = true;
1967                 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1968         }
1969
1970         if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1971                 ret = true;
1972                 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1973         }
1974
1975         if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1976                 ret = true;
1977                 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1978         }
1979
1980         return ret;
1981 }
1982
1983 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
1984                            struct nlattr *tb[], struct nlattr *data[],
1985                            struct netlink_ext_ack *extack)
1986 {
1987         struct net *net = dev_net(dev);
1988         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1989         struct ip_tunnel_encap ipencap;
1990         struct ip6_tnl *nt, *t;
1991         int err;
1992
1993         nt = netdev_priv(dev);
1994
1995         if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
1996                 err = ip6_tnl_encap_setup(nt, &ipencap);
1997                 if (err < 0)
1998                         return err;
1999         }
2000
2001         ip6_tnl_netlink_parms(data, &nt->parms);
2002
2003         if (nt->parms.collect_md) {
2004                 if (rtnl_dereference(ip6n->collect_md_tun))
2005                         return -EEXIST;
2006         } else {
2007                 t = ip6_tnl_locate(net, &nt->parms, 0);
2008                 if (!IS_ERR(t))
2009                         return -EEXIST;
2010         }
2011
2012         err = ip6_tnl_create2(dev);
2013         if (!err && tb[IFLA_MTU])
2014                 ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
2015
2016         return err;
2017 }
2018
2019 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
2020                               struct nlattr *data[],
2021                               struct netlink_ext_ack *extack)
2022 {
2023         struct ip6_tnl *t = netdev_priv(dev);
2024         struct __ip6_tnl_parm p;
2025         struct net *net = t->net;
2026         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2027         struct ip_tunnel_encap ipencap;
2028
2029         if (dev == ip6n->fb_tnl_dev)
2030                 return -EINVAL;
2031
2032         if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2033                 int err = ip6_tnl_encap_setup(t, &ipencap);
2034
2035                 if (err < 0)
2036                         return err;
2037         }
2038         ip6_tnl_netlink_parms(data, &p);
2039         if (p.collect_md)
2040                 return -EINVAL;
2041
2042         t = ip6_tnl_locate(net, &p, 0);
2043         if (!IS_ERR(t)) {
2044                 if (t->dev != dev)
2045                         return -EEXIST;
2046         } else
2047                 t = netdev_priv(dev);
2048
2049         return ip6_tnl_update(t, &p);
2050 }
2051
2052 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2053 {
2054         struct net *net = dev_net(dev);
2055         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2056
2057         if (dev != ip6n->fb_tnl_dev)
2058                 unregister_netdevice_queue(dev, head);
2059 }
2060
2061 static size_t ip6_tnl_get_size(const struct net_device *dev)
2062 {
2063         return
2064                 /* IFLA_IPTUN_LINK */
2065                 nla_total_size(4) +
2066                 /* IFLA_IPTUN_LOCAL */
2067                 nla_total_size(sizeof(struct in6_addr)) +
2068                 /* IFLA_IPTUN_REMOTE */
2069                 nla_total_size(sizeof(struct in6_addr)) +
2070                 /* IFLA_IPTUN_TTL */
2071                 nla_total_size(1) +
2072                 /* IFLA_IPTUN_ENCAP_LIMIT */
2073                 nla_total_size(1) +
2074                 /* IFLA_IPTUN_FLOWINFO */
2075                 nla_total_size(4) +
2076                 /* IFLA_IPTUN_FLAGS */
2077                 nla_total_size(4) +
2078                 /* IFLA_IPTUN_PROTO */
2079                 nla_total_size(1) +
2080                 /* IFLA_IPTUN_ENCAP_TYPE */
2081                 nla_total_size(2) +
2082                 /* IFLA_IPTUN_ENCAP_FLAGS */
2083                 nla_total_size(2) +
2084                 /* IFLA_IPTUN_ENCAP_SPORT */
2085                 nla_total_size(2) +
2086                 /* IFLA_IPTUN_ENCAP_DPORT */
2087                 nla_total_size(2) +
2088                 /* IFLA_IPTUN_COLLECT_METADATA */
2089                 nla_total_size(0) +
2090                 /* IFLA_IPTUN_FWMARK */
2091                 nla_total_size(4) +
2092                 0;
2093 }
2094
2095 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2096 {
2097         struct ip6_tnl *tunnel = netdev_priv(dev);
2098         struct __ip6_tnl_parm *parm = &tunnel->parms;
2099
2100         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2101             nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2102             nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2103             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2104             nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2105             nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2106             nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2107             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
2108             nla_put_u32(skb, IFLA_IPTUN_FWMARK, parm->fwmark))
2109                 goto nla_put_failure;
2110
2111         if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2112             nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2113             nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2114             nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2115                 goto nla_put_failure;
2116
2117         if (parm->collect_md)
2118                 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2119                         goto nla_put_failure;
2120
2121         return 0;
2122
2123 nla_put_failure:
2124         return -EMSGSIZE;
2125 }
2126
2127 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2128 {
2129         struct ip6_tnl *tunnel = netdev_priv(dev);
2130
2131         return tunnel->net;
2132 }
2133 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2134
2135 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2136         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
2137         [IFLA_IPTUN_LOCAL]              = { .len = sizeof(struct in6_addr) },
2138         [IFLA_IPTUN_REMOTE]             = { .len = sizeof(struct in6_addr) },
2139         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
2140         [IFLA_IPTUN_ENCAP_LIMIT]        = { .type = NLA_U8 },
2141         [IFLA_IPTUN_FLOWINFO]           = { .type = NLA_U32 },
2142         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U32 },
2143         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
2144         [IFLA_IPTUN_ENCAP_TYPE]         = { .type = NLA_U16 },
2145         [IFLA_IPTUN_ENCAP_FLAGS]        = { .type = NLA_U16 },
2146         [IFLA_IPTUN_ENCAP_SPORT]        = { .type = NLA_U16 },
2147         [IFLA_IPTUN_ENCAP_DPORT]        = { .type = NLA_U16 },
2148         [IFLA_IPTUN_COLLECT_METADATA]   = { .type = NLA_FLAG },
2149         [IFLA_IPTUN_FWMARK]             = { .type = NLA_U32 },
2150 };
2151
2152 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2153         .kind           = "ip6tnl",
2154         .maxtype        = IFLA_IPTUN_MAX,
2155         .policy         = ip6_tnl_policy,
2156         .priv_size      = sizeof(struct ip6_tnl),
2157         .setup          = ip6_tnl_dev_setup,
2158         .validate       = ip6_tnl_validate,
2159         .newlink        = ip6_tnl_newlink,
2160         .changelink     = ip6_tnl_changelink,
2161         .dellink        = ip6_tnl_dellink,
2162         .get_size       = ip6_tnl_get_size,
2163         .fill_info      = ip6_tnl_fill_info,
2164         .get_link_net   = ip6_tnl_get_link_net,
2165 };
2166
2167 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2168         .handler        = ip4ip6_rcv,
2169         .err_handler    = ip4ip6_err,
2170         .priority       =       1,
2171 };
2172
2173 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2174         .handler        = ip6ip6_rcv,
2175         .err_handler    = ip6ip6_err,
2176         .priority       =       1,
2177 };
2178
2179 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net, struct list_head *list)
2180 {
2181         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2182         struct net_device *dev, *aux;
2183         int h;
2184         struct ip6_tnl *t;
2185
2186         for_each_netdev_safe(net, dev, aux)
2187                 if (dev->rtnl_link_ops == &ip6_link_ops)
2188                         unregister_netdevice_queue(dev, list);
2189
2190         for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2191                 t = rtnl_dereference(ip6n->tnls_r_l[h]);
2192                 while (t) {
2193                         /* If dev is in the same netns, it has already
2194                          * been added to the list by the previous loop.
2195                          */
2196                         if (!net_eq(dev_net(t->dev), net))
2197                                 unregister_netdevice_queue(t->dev, list);
2198                         t = rtnl_dereference(t->next);
2199                 }
2200         }
2201 }
2202
2203 static int __net_init ip6_tnl_init_net(struct net *net)
2204 {
2205         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2206         struct ip6_tnl *t = NULL;
2207         int err;
2208
2209         ip6n->tnls[0] = ip6n->tnls_wc;
2210         ip6n->tnls[1] = ip6n->tnls_r_l;
2211
2212         if (!net_has_fallback_tunnels(net))
2213                 return 0;
2214         err = -ENOMEM;
2215         ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2216                                         NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2217
2218         if (!ip6n->fb_tnl_dev)
2219                 goto err_alloc_dev;
2220         dev_net_set(ip6n->fb_tnl_dev, net);
2221         ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2222         /* FB netdevice is special: we have one, and only one per netns.
2223          * Allowing to move it to another netns is clearly unsafe.
2224          */
2225         ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2226
2227         err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2228         if (err < 0)
2229                 goto err_register;
2230
2231         err = register_netdev(ip6n->fb_tnl_dev);
2232         if (err < 0)
2233                 goto err_register;
2234
2235         t = netdev_priv(ip6n->fb_tnl_dev);
2236
2237         strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2238         return 0;
2239
2240 err_register:
2241         free_netdev(ip6n->fb_tnl_dev);
2242 err_alloc_dev:
2243         return err;
2244 }
2245
2246 static void __net_exit ip6_tnl_exit_batch_net(struct list_head *net_list)
2247 {
2248         struct net *net;
2249         LIST_HEAD(list);
2250
2251         rtnl_lock();
2252         list_for_each_entry(net, net_list, exit_list)
2253                 ip6_tnl_destroy_tunnels(net, &list);
2254         unregister_netdevice_many(&list);
2255         rtnl_unlock();
2256 }
2257
2258 static struct pernet_operations ip6_tnl_net_ops = {
2259         .init = ip6_tnl_init_net,
2260         .exit_batch = ip6_tnl_exit_batch_net,
2261         .id   = &ip6_tnl_net_id,
2262         .size = sizeof(struct ip6_tnl_net),
2263 };
2264
2265 /**
2266  * ip6_tunnel_init - register protocol and reserve needed resources
2267  *
2268  * Return: 0 on success
2269  **/
2270
2271 static int __init ip6_tunnel_init(void)
2272 {
2273         int  err;
2274
2275         if (!ipv6_mod_enabled())
2276                 return -EOPNOTSUPP;
2277
2278         err = register_pernet_device(&ip6_tnl_net_ops);
2279         if (err < 0)
2280                 goto out_pernet;
2281
2282         err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2283         if (err < 0) {
2284                 pr_err("%s: can't register ip4ip6\n", __func__);
2285                 goto out_ip4ip6;
2286         }
2287
2288         err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2289         if (err < 0) {
2290                 pr_err("%s: can't register ip6ip6\n", __func__);
2291                 goto out_ip6ip6;
2292         }
2293         err = rtnl_link_register(&ip6_link_ops);
2294         if (err < 0)
2295                 goto rtnl_link_failed;
2296
2297         return 0;
2298
2299 rtnl_link_failed:
2300         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2301 out_ip6ip6:
2302         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2303 out_ip4ip6:
2304         unregister_pernet_device(&ip6_tnl_net_ops);
2305 out_pernet:
2306         return err;
2307 }
2308
2309 /**
2310  * ip6_tunnel_cleanup - free resources and unregister protocol
2311  **/
2312
2313 static void __exit ip6_tunnel_cleanup(void)
2314 {
2315         rtnl_link_unregister(&ip6_link_ops);
2316         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2317                 pr_info("%s: can't deregister ip4ip6\n", __func__);
2318
2319         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2320                 pr_info("%s: can't deregister ip6ip6\n", __func__);
2321
2322         unregister_pernet_device(&ip6_tnl_net_ops);
2323 }
2324
2325 module_init(ip6_tunnel_init);
2326 module_exit(ip6_tunnel_cleanup);