net/ipv6/ip6_tunnel.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      IPv6 tunneling device
   4  *      Linux INET6 implementation
   5  *
   6  *      Authors:
   7  *      Ville Nuorvala          <vnuorval@tcs.hut.fi>
   8  *      Yasuyuki Kozakai        <kozakai@linux-ipv6.org>
   9  *
  10  *      Based on:
  11  *      linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
  12  *
  13  *      RFC 2473
  14  */
  15
  16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  17
  18 #include <linux/module.h>
  19 #include <linux/capability.h>
  20 #include <linux/errno.h>
  21 #include <linux/types.h>
  22 #include <linux/sockios.h>
  23 #include <linux/icmp.h>
  24 #include <linux/if.h>
  25 #include <linux/in.h>
  26 #include <linux/ip.h>
  27 #include <linux/net.h>
  28 #include <linux/in6.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/if_arp.h>
  31 #include <linux/icmpv6.h>
  32 #include <linux/init.h>
  33 #include <linux/route.h>
  34 #include <linux/rtnetlink.h>
  35 #include <linux/netfilter_ipv6.h>
  36 #include <linux/slab.h>
  37 #include <linux/hash.h>
  38 #include <linux/etherdevice.h>
  39
  40 #include <linux/uaccess.h>
  41 #include <linux/atomic.h>
  42
  43 #include <net/icmp.h>
  44 #include <net/ip.h>
  45 #include <net/ip_tunnels.h>
  46 #include <net/ipv6.h>
  47 #include <net/ip6_route.h>
  48 #include <net/addrconf.h>
  49 #include <net/ip6_tunnel.h>
  50 #include <net/xfrm.h>
  51 #include <net/dsfield.h>
  52 #include <net/inet_ecn.h>
  53 #include <net/net_namespace.h>
  54 #include <net/netns/generic.h>
  55 #include <net/dst_metadata.h>
  56
  57 MODULE_AUTHOR("Ville Nuorvala");
  58 MODULE_DESCRIPTION("IPv6 tunneling device");
  59 MODULE_LICENSE("GPL");
  60 MODULE_ALIAS_RTNL_LINK("ip6tnl");
  61 MODULE_ALIAS_NETDEV("ip6tnl0");
  62
  63 #define IP6_TUNNEL_HASH_SIZE_SHIFT  5
  64 #define IP6_TUNNEL_HASH_SIZE (1 << IP6_TUNNEL_HASH_SIZE_SHIFT)
  65
  66 static bool log_ecn_error = true;
  67 module_param(log_ecn_error, bool, 0644);
  68 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  69
  70 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2)
  71 {
  72         u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2);
  73
  74         return hash_32(hash, IP6_TUNNEL_HASH_SIZE_SHIFT);
  75 }
  76
  77 static int ip6_tnl_dev_init(struct net_device *dev);
  78 static void ip6_tnl_dev_setup(struct net_device *dev);
  79 static struct rtnl_link_ops ip6_link_ops __read_mostly;
  80
  81 static unsigned int ip6_tnl_net_id __read_mostly;
  82 struct ip6_tnl_net {
  83         /* the IPv6 tunnel fallback device */
  84         struct net_device *fb_tnl_dev;
  85         /* lists for storing tunnels in use */
  86         struct ip6_tnl __rcu *tnls_r_l[IP6_TUNNEL_HASH_SIZE];
  87         struct ip6_tnl __rcu *tnls_wc[1];
  88         struct ip6_tnl __rcu **tnls[2];
  89         struct ip6_tnl __rcu *collect_md_tun;
  90 };
  91
  92 static inline int ip6_tnl_mpls_supported(void)
  93 {
  94         return IS_ENABLED(CONFIG_MPLS);
  95 }
  96
  97 #define for_each_ip6_tunnel_rcu(start) \
  98         for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
  99
 100 /**
 101  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
 102  *   @net: network namespace
 103  *   @link: ifindex of underlying interface
 104  *   @remote: the address of the tunnel exit-point
 105  *   @local: the address of the tunnel entry-point
 106  *
 107  * Return:
 108  *   tunnel matching given end-points if found,
 109  *   else fallback tunnel if its device is up,
 110  *   else %NULL
 111  **/
 112
 113 static struct ip6_tnl *
 114 ip6_tnl_lookup(struct net *net, int link,
 115                const struct in6_addr *remote, const struct in6_addr *local)
 116 {
 117         unsigned int hash = HASH(remote, local);
 118         struct ip6_tnl *t, *cand = NULL;
 119         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 120         struct in6_addr any;
 121
 122         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 123                 if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 124                     !ipv6_addr_equal(remote, &t->parms.raddr) ||
 125                     !(t->dev->flags & IFF_UP))
 126                         continue;
 127
 128                 if (link == t->parms.link)
 129                         return t;
 130                 else
 131                         cand = t;
 132         }
 133
 134         memset(&any, 0, sizeof(any));
 135         hash = HASH(&any, local);
 136         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 137                 if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 138                     !ipv6_addr_any(&t->parms.raddr) ||
 139                     !(t->dev->flags & IFF_UP))
 140                         continue;
 141
 142                 if (link == t->parms.link)
 143                         return t;
 144                 else if (!cand)
 145                         cand = t;
 146         }
 147
 148         hash = HASH(remote, &any);
 149         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 150                 if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
 151                     !ipv6_addr_any(&t->parms.laddr) ||
 152                     !(t->dev->flags & IFF_UP))
 153                         continue;
 154
 155                 if (link == t->parms.link)
 156                         return t;
 157                 else if (!cand)
 158                         cand = t;
 159         }
 160
 161         if (cand)
 162                 return cand;
 163
 164         t = rcu_dereference(ip6n->collect_md_tun);
 165         if (t && t->dev->flags & IFF_UP)
 166                 return t;
 167
 168         t = rcu_dereference(ip6n->tnls_wc[0]);
 169         if (t && (t->dev->flags & IFF_UP))
 170                 return t;
 171
 172         return NULL;
 173 }
 174
 175 /**
 176  * ip6_tnl_bucket - get head of list matching given tunnel parameters
 177  *   @ip6n: the private data for ip6_vti in the netns
 178  *   @p: parameters containing tunnel end-points
 179  *
 180  * Description:
 181  *   ip6_tnl_bucket() returns the head of the list matching the
 182  *   &struct in6_addr entries laddr and raddr in @p.
 183  *
 184  * Return: head of IPv6 tunnel list
 185  **/
 186
 187 static struct ip6_tnl __rcu **
 188 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
 189 {
 190         const struct in6_addr *remote = &p->raddr;
 191         const struct in6_addr *local = &p->laddr;
 192         unsigned int h = 0;
 193         int prio = 0;
 194
 195         if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
 196                 prio = 1;
 197                 h = HASH(remote, local);
 198         }
 199         return &ip6n->tnls[prio][h];
 200 }
 201
 202 /**
 203  * ip6_tnl_link - add tunnel to hash table
 204  *   @ip6n: the private data for ip6_vti in the netns
 205  *   @t: tunnel to be added
 206  **/
 207
 208 static void
 209 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 210 {
 211         struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
 212
 213         if (t->parms.collect_md)
 214                 rcu_assign_pointer(ip6n->collect_md_tun, t);
 215         rcu_assign_pointer(t->next , rtnl_dereference(*tp));
 216         rcu_assign_pointer(*tp, t);
 217 }
 218
 219 /**
 220  * ip6_tnl_unlink - remove tunnel from hash table
 221  *   @ip6n: the private data for ip6_vti in the netns
 222  *   @t: tunnel to be removed
 223  **/
 224
 225 static void
 226 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 227 {
 228         struct ip6_tnl __rcu **tp;
 229         struct ip6_tnl *iter;
 230
 231         if (t->parms.collect_md)
 232                 rcu_assign_pointer(ip6n->collect_md_tun, NULL);
 233
 234         for (tp = ip6_tnl_bucket(ip6n, &t->parms);
 235              (iter = rtnl_dereference(*tp)) != NULL;
 236              tp = &iter->next) {
 237                 if (t == iter) {
 238                         rcu_assign_pointer(*tp, t->next);
 239                         break;
 240                 }
 241         }
 242 }
 243
 244 static void ip6_dev_free(struct net_device *dev)
 245 {
 246         struct ip6_tnl *t = netdev_priv(dev);
 247
 248         gro_cells_destroy(&t->gro_cells);
 249         dst_cache_destroy(&t->dst_cache);
 250         free_percpu(dev->tstats);
 251 }
 252
 253 static int ip6_tnl_create2(struct net_device *dev)
 254 {
 255         struct ip6_tnl *t = netdev_priv(dev);
 256         struct net *net = dev_net(dev);
 257         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 258         int err;
 259
 260         dev->rtnl_link_ops = &ip6_link_ops;
 261         err = register_netdevice(dev);
 262         if (err < 0)
 263                 goto out;
 264
 265         strcpy(t->parms.name, dev->name);
 266
 267         ip6_tnl_link(ip6n, t);
 268         return 0;
 269
 270 out:
 271         return err;
 272 }
 273
 274 /**
 275  * ip6_tnl_create - create a new tunnel
 276  *   @net: network namespace
 277  *   @p: tunnel parameters
 278  *
 279  * Description:
 280  *   Create tunnel matching given parameters.
 281  *
 282  * Return:
 283  *   created tunnel or error pointer
 284  **/
 285
 286 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
 287 {
 288         struct net_device *dev;
 289         struct ip6_tnl *t;
 290         char name[IFNAMSIZ];
 291         int err = -E2BIG;
 292
 293         if (p->name[0]) {
 294                 if (!dev_valid_name(p->name))
 295                         goto failed;
 296                 strscpy(name, p->name, IFNAMSIZ);
 297         } else {
 298                 sprintf(name, "ip6tnl%%d");
 299         }
 300         err = -ENOMEM;
 301         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 302                            ip6_tnl_dev_setup);
 303         if (!dev)
 304                 goto failed;
 305
 306         dev_net_set(dev, net);
 307
 308         t = netdev_priv(dev);
 309         t->parms = *p;
 310         t->net = dev_net(dev);
 311         err = ip6_tnl_create2(dev);
 312         if (err < 0)
 313                 goto failed_free;
 314
 315         return t;
 316
 317 failed_free:
 318         free_netdev(dev);
 319 failed:
 320         return ERR_PTR(err);
 321 }
 322
 323 /**
 324  * ip6_tnl_locate - find or create tunnel matching given parameters
 325  *   @net: network namespace
 326  *   @p: tunnel parameters
 327  *   @create: != 0 if allowed to create new tunnel if no match found
 328  *
 329  * Description:
 330  *   ip6_tnl_locate() first tries to locate an existing tunnel
 331  *   based on @parms. If this is unsuccessful, but @create is set a new
 332  *   tunnel device is created and registered for use.
 333  *
 334  * Return:
 335  *   matching tunnel or error pointer
 336  **/
 337
 338 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
 339                 struct __ip6_tnl_parm *p, int create)
 340 {
 341         const struct in6_addr *remote = &p->raddr;
 342         const struct in6_addr *local = &p->laddr;
 343         struct ip6_tnl __rcu **tp;
 344         struct ip6_tnl *t;
 345         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 346
 347         for (tp = ip6_tnl_bucket(ip6n, p);
 348              (t = rtnl_dereference(*tp)) != NULL;
 349              tp = &t->next) {
 350                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 351                     ipv6_addr_equal(remote, &t->parms.raddr) &&
 352                     p->link == t->parms.link) {
 353                         if (create)
 354                                 return ERR_PTR(-EEXIST);
 355
 356                         return t;
 357                 }
 358         }
 359         if (!create)
 360                 return ERR_PTR(-ENODEV);
 361         return ip6_tnl_create(net, p);
 362 }
 363
 364 /**
 365  * ip6_tnl_dev_uninit - tunnel device uninitializer
 366  *   @dev: the device to be destroyed
 367  *
 368  * Description:
 369  *   ip6_tnl_dev_uninit() removes tunnel from its list
 370  **/
 371
 372 static void
 373 ip6_tnl_dev_uninit(struct net_device *dev)
 374 {
 375         struct ip6_tnl *t = netdev_priv(dev);
 376         struct net *net = t->net;
 377         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 378
 379         if (dev == ip6n->fb_tnl_dev)
 380                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
 381         else
 382                 ip6_tnl_unlink(ip6n, t);
 383         dst_cache_reset(&t->dst_cache);
 384         netdev_put(dev, &t->dev_tracker);
 385 }
 386
 387 /**
 388  * ip6_tnl_parse_tlv_enc_lim - handle encapsulation limit option
 389  *   @skb: received socket buffer
 390  *   @raw: the ICMPv6 error message data
 391  *
 392  * Return:
 393  *   0 if none was found,
 394  *   else index to encapsulation limit
 395  **/
 396
 397 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
 398 {
 399         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)raw;
 400         unsigned int nhoff = raw - skb->data;
 401         unsigned int off = nhoff + sizeof(*ipv6h);
 402         u8 nexthdr = ipv6h->nexthdr;
 403
 404         while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
 405                 struct ipv6_opt_hdr *hdr;
 406                 u16 optlen;
 407
 408                 if (!pskb_may_pull(skb, off + sizeof(*hdr)))
 409                         break;
 410
 411                 hdr = (struct ipv6_opt_hdr *)(skb->data + off);
 412                 if (nexthdr == NEXTHDR_FRAGMENT) {
 413                         optlen = 8;
 414                 } else if (nexthdr == NEXTHDR_AUTH) {
 415                         optlen = ipv6_authlen(hdr);
 416                 } else {
 417                         optlen = ipv6_optlen(hdr);
 418                 }
 419
 420                 if (!pskb_may_pull(skb, off + optlen))
 421                         break;
 422
 423                 hdr = (struct ipv6_opt_hdr *)(skb->data + off);
 424                 if (nexthdr == NEXTHDR_FRAGMENT) {
 425                         struct frag_hdr *frag_hdr = (struct frag_hdr *)hdr;
 426
 427                         if (frag_hdr->frag_off)
 428                                 break;
 429                 }
 430                 if (nexthdr == NEXTHDR_DEST) {
 431                         u16 i = 2;
 432
 433                         while (1) {
 434                                 struct ipv6_tlv_tnl_enc_lim *tel;
 435
 436                                 /* No more room for encapsulation limit */
 437                                 if (i + sizeof(*tel) > optlen)
 438                                         break;
 439
 440                                 tel = (struct ipv6_tlv_tnl_enc_lim *)(skb->data + off + i);
 441                                 /* return index of option if found and valid */
 442                                 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
 443                                     tel->length == 1)
 444                                         return i + off - nhoff;
 445                                 /* else jump to next option */
 446                                 if (tel->type)
 447                                         i += tel->length + 2;
 448                                 else
 449                                         i++;
 450                         }
 451                 }
 452                 nexthdr = hdr->nexthdr;
 453                 off += optlen;
 454         }
 455         return 0;
 456 }
 457 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
 458
 459 /* ip6_tnl_err() should handle errors in the tunnel according to the
 460  * specifications in RFC 2473.
 461  */
 462 static int
 463 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
 464             u8 *type, u8 *code, int *msg, __u32 *info, int offset)
 465 {
 466         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 467         struct net *net = dev_net(skb->dev);
 468         u8 rel_type = ICMPV6_DEST_UNREACH;
 469         u8 rel_code = ICMPV6_ADDR_UNREACH;
 470         __u32 rel_info = 0;
 471         struct ip6_tnl *t;
 472         int err = -ENOENT;
 473         int rel_msg = 0;
 474         u8 tproto;
 475         __u16 len;
 476
 477         /* If the packet doesn't contain the original IPv6 header we are
 478            in trouble since we might need the source address for further
 479            processing of the error. */
 480
 481         rcu_read_lock();
 482         t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->daddr, &ipv6h->saddr);
 483         if (!t)
 484                 goto out;
 485
 486         tproto = READ_ONCE(t->parms.proto);
 487         if (tproto != ipproto && tproto != 0)
 488                 goto out;
 489
 490         err = 0;
 491
 492         switch (*type) {
 493         case ICMPV6_DEST_UNREACH:
 494                 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
 495                                     t->parms.name);
 496                 rel_msg = 1;
 497                 break;
 498         case ICMPV6_TIME_EXCEED:
 499                 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
 500                         net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 501                                             t->parms.name);
 502                         rel_msg = 1;
 503                 }
 504                 break;
 505         case ICMPV6_PARAMPROB: {
 506                 struct ipv6_tlv_tnl_enc_lim *tel;
 507                 __u32 teli;
 508
 509                 teli = 0;
 510                 if ((*code) == ICMPV6_HDR_FIELD)
 511                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 512
 513                 if (teli && teli == *info - 2) {
 514                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 515                         if (tel->encap_limit == 0) {
 516                                 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 517                                                     t->parms.name);
 518                                 rel_msg = 1;
 519                         }
 520                 } else {
 521                         net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 522                                             t->parms.name);
 523                 }
 524                 break;
 525         }
 526         case ICMPV6_PKT_TOOBIG: {
 527                 __u32 mtu;
 528
 529                 ip6_update_pmtu(skb, net, htonl(*info), 0, 0,
 530                                 sock_net_uid(net, NULL));
 531                 mtu = *info - offset;
 532                 if (mtu < IPV6_MIN_MTU)
 533                         mtu = IPV6_MIN_MTU;
 534                 len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
 535                 if (len > mtu) {
 536                         rel_type = ICMPV6_PKT_TOOBIG;
 537                         rel_code = 0;
 538                         rel_info = mtu;
 539                         rel_msg = 1;
 540                 }
 541                 break;
 542         }
 543         case NDISC_REDIRECT:
 544                 ip6_redirect(skb, net, skb->dev->ifindex, 0,
 545                              sock_net_uid(net, NULL));
 546                 break;
 547         }
 548
 549         *type = rel_type;
 550         *code = rel_code;
 551         *info = rel_info;
 552         *msg = rel_msg;
 553
 554 out:
 555         rcu_read_unlock();
 556         return err;
 557 }
 558
 559 static int
 560 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 561            u8 type, u8 code, int offset, __be32 info)
 562 {
 563         __u32 rel_info = ntohl(info);
 564         const struct iphdr *eiph;
 565         struct sk_buff *skb2;
 566         int err, rel_msg = 0;
 567         u8 rel_type = type;
 568         u8 rel_code = code;
 569         struct rtable *rt;
 570         struct flowi4 fl4;
 571
 572         err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
 573                           &rel_msg, &rel_info, offset);
 574         if (err < 0)
 575                 return err;
 576
 577         if (rel_msg == 0)
 578                 return 0;
 579
 580         switch (rel_type) {
 581         case ICMPV6_DEST_UNREACH:
 582                 if (rel_code != ICMPV6_ADDR_UNREACH)
 583                         return 0;
 584                 rel_type = ICMP_DEST_UNREACH;
 585                 rel_code = ICMP_HOST_UNREACH;
 586                 break;
 587         case ICMPV6_PKT_TOOBIG:
 588                 if (rel_code != 0)
 589                         return 0;
 590                 rel_type = ICMP_DEST_UNREACH;
 591                 rel_code = ICMP_FRAG_NEEDED;
 592                 break;
 593         default:
 594                 return 0;
 595         }
 596
 597         if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
 598                 return 0;
 599
 600         skb2 = skb_clone(skb, GFP_ATOMIC);
 601         if (!skb2)
 602                 return 0;
 603
 604         skb_dst_drop(skb2);
 605
 606         skb_pull(skb2, offset);
 607         skb_reset_network_header(skb2);
 608         eiph = ip_hdr(skb2);
 609
 610         /* Try to guess incoming interface */
 611         rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, eiph->saddr,
 612                                    0, 0, 0, IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 613         if (IS_ERR(rt))
 614                 goto out;
 615
 616         skb2->dev = rt->dst.dev;
 617         ip_rt_put(rt);
 618
 619         /* route "incoming" packet */
 620         if (rt->rt_flags & RTCF_LOCAL) {
 621                 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 622                                            eiph->daddr, eiph->saddr, 0, 0,
 623                                            IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 624                 if (IS_ERR(rt) || rt->dst.dev->type != ARPHRD_TUNNEL6) {
 625                         if (!IS_ERR(rt))
 626                                 ip_rt_put(rt);
 627                         goto out;
 628                 }
 629                 skb_dst_set(skb2, &rt->dst);
 630         } else {
 631                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
 632                                    skb2->dev) ||
 633                     skb_dst(skb2)->dev->type != ARPHRD_TUNNEL6)
 634                         goto out;
 635         }
 636
 637         /* change mtu on this route */
 638         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
 639                 if (rel_info > dst_mtu(skb_dst(skb2)))
 640                         goto out;
 641
 642                 skb_dst_update_pmtu_no_confirm(skb2, rel_info);
 643         }
 644
 645         icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
 646
 647 out:
 648         kfree_skb(skb2);
 649         return 0;
 650 }
 651
 652 static int
 653 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 654            u8 type, u8 code, int offset, __be32 info)
 655 {
 656         __u32 rel_info = ntohl(info);
 657         int err, rel_msg = 0;
 658         u8 rel_type = type;
 659         u8 rel_code = code;
 660
 661         err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
 662                           &rel_msg, &rel_info, offset);
 663         if (err < 0)
 664                 return err;
 665
 666         if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
 667                 struct rt6_info *rt;
 668                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 669
 670                 if (!skb2)
 671                         return 0;
 672
 673                 skb_dst_drop(skb2);
 674                 skb_pull(skb2, offset);
 675                 skb_reset_network_header(skb2);
 676
 677                 /* Try to guess incoming interface */
 678                 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
 679                                 NULL, 0, skb2, 0);
 680
 681                 if (rt && rt->dst.dev)
 682                         skb2->dev = rt->dst.dev;
 683
 684                 icmpv6_send(skb2, rel_type, rel_code, rel_info);
 685
 686                 ip6_rt_put(rt);
 687
 688                 kfree_skb(skb2);
 689         }
 690
 691         return 0;
 692 }
 693
 694 static int
 695 mplsip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 696             u8 type, u8 code, int offset, __be32 info)
 697 {
 698         __u32 rel_info = ntohl(info);
 699         int err, rel_msg = 0;
 700         u8 rel_type = type;
 701         u8 rel_code = code;
 702
 703         err = ip6_tnl_err(skb, IPPROTO_MPLS, opt, &rel_type, &rel_code,
 704                           &rel_msg, &rel_info, offset);
 705         return err;
 706 }
 707
 708 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 709                                        const struct ipv6hdr *ipv6h,
 710                                        struct sk_buff *skb)
 711 {
 712         __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
 713
 714         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 715                 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
 716
 717         return IP6_ECN_decapsulate(ipv6h, skb);
 718 }
 719
 720 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 721                                        const struct ipv6hdr *ipv6h,
 722                                        struct sk_buff *skb)
 723 {
 724         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 725                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
 726
 727         return IP6_ECN_decapsulate(ipv6h, skb);
 728 }
 729
 730 static inline int mplsip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 731                                                const struct ipv6hdr *ipv6h,
 732                                                struct sk_buff *skb)
 733 {
 734         /* ECN is not supported in AF_MPLS */
 735         return 0;
 736 }
 737
 738 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
 739                              const struct in6_addr *laddr,
 740                              const struct in6_addr *raddr)
 741 {
 742         struct __ip6_tnl_parm *p = &t->parms;
 743         int ltype = ipv6_addr_type(laddr);
 744         int rtype = ipv6_addr_type(raddr);
 745         __u32 flags = 0;
 746
 747         if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
 748                 flags = IP6_TNL_F_CAP_PER_PACKET;
 749         } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 750                    rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 751                    !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
 752                    (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
 753                 if (ltype&IPV6_ADDR_UNICAST)
 754                         flags |= IP6_TNL_F_CAP_XMIT;
 755                 if (rtype&IPV6_ADDR_UNICAST)
 756                         flags |= IP6_TNL_F_CAP_RCV;
 757         }
 758         return flags;
 759 }
 760 EXPORT_SYMBOL(ip6_tnl_get_cap);
 761
 762 /* called with rcu_read_lock() */
 763 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
 764                                   const struct in6_addr *laddr,
 765                                   const struct in6_addr *raddr)
 766 {
 767         struct __ip6_tnl_parm *p = &t->parms;
 768         int ret = 0;
 769         struct net *net = t->net;
 770
 771         if ((p->flags & IP6_TNL_F_CAP_RCV) ||
 772             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
 773              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
 774                 struct net_device *ldev = NULL;
 775
 776                 if (p->link)
 777                         ldev = dev_get_by_index_rcu(net, p->link);
 778
 779                 if ((ipv6_addr_is_multicast(laddr) ||
 780                      likely(ipv6_chk_addr_and_flags(net, laddr, ldev, false,
 781                                                     0, IFA_F_TENTATIVE))) &&
 782                     ((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
 783                      likely(!ipv6_chk_addr_and_flags(net, raddr, ldev, true,
 784                                                      0, IFA_F_TENTATIVE))))
 785                         ret = 1;
 786         }
 787         return ret;
 788 }
 789 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
 790
 791 static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
 792                          const struct tnl_ptk_info *tpi,
 793                          struct metadata_dst *tun_dst,
 794                          int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 795                                                 const struct ipv6hdr *ipv6h,
 796                                                 struct sk_buff *skb),
 797                          bool log_ecn_err)
 798 {
 799         const struct ipv6hdr *ipv6h;
 800         int nh, err;
 801
 802         if ((!(tpi->flags & TUNNEL_CSUM) &&
 803              (tunnel->parms.i_flags & TUNNEL_CSUM)) ||
 804             ((tpi->flags & TUNNEL_CSUM) &&
 805              !(tunnel->parms.i_flags & TUNNEL_CSUM))) {
 806                 tunnel->dev->stats.rx_crc_errors++;
 807                 tunnel->dev->stats.rx_errors++;
 808                 goto drop;
 809         }
 810
 811         if (tunnel->parms.i_flags & TUNNEL_SEQ) {
 812                 if (!(tpi->flags & TUNNEL_SEQ) ||
 813                     (tunnel->i_seqno &&
 814                      (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
 815                         tunnel->dev->stats.rx_fifo_errors++;
 816                         tunnel->dev->stats.rx_errors++;
 817                         goto drop;
 818                 }
 819                 tunnel->i_seqno = ntohl(tpi->seq) + 1;
 820         }
 821
 822         skb->protocol = tpi->proto;
 823
 824         /* Warning: All skb pointers will be invalidated! */
 825         if (tunnel->dev->type == ARPHRD_ETHER) {
 826                 if (!pskb_may_pull(skb, ETH_HLEN)) {
 827                         tunnel->dev->stats.rx_length_errors++;
 828                         tunnel->dev->stats.rx_errors++;
 829                         goto drop;
 830                 }
 831
 832                 skb->protocol = eth_type_trans(skb, tunnel->dev);
 833                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 834         } else {
 835                 skb->dev = tunnel->dev;
 836                 skb_reset_mac_header(skb);
 837         }
 838
 839         /* Save offset of outer header relative to skb->head,
 840          * because we are going to reset the network header to the inner header
 841          * and might change skb->head.
 842          */
 843         nh = skb_network_header(skb) - skb->head;
 844
 845         skb_reset_network_header(skb);
 846
 847         if (!pskb_inet_may_pull(skb)) {
 848                 DEV_STATS_INC(tunnel->dev, rx_length_errors);
 849                 DEV_STATS_INC(tunnel->dev, rx_errors);
 850                 goto drop;
 851         }
 852
 853         /* Get the outer header. */
 854         ipv6h = (struct ipv6hdr *)(skb->head + nh);
 855
 856         memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 857
 858         __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 859
 860         err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
 861         if (unlikely(err)) {
 862                 if (log_ecn_err)
 863                         net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
 864                                              &ipv6h->saddr,
 865                                              ipv6_get_dsfield(ipv6h));
 866                 if (err > 1) {
 867                         ++tunnel->dev->stats.rx_frame_errors;
 868                         ++tunnel->dev->stats.rx_errors;
 869                         goto drop;
 870                 }
 871         }
 872
 873         dev_sw_netstats_rx_add(tunnel->dev, skb->len);
 874
 875         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
 876
 877         if (tun_dst)
 878                 skb_dst_set(skb, (struct dst_entry *)tun_dst);
 879
 880         gro_cells_receive(&tunnel->gro_cells, skb);
 881         return 0;
 882
 883 drop:
 884         if (tun_dst)
 885                 dst_release((struct dst_entry *)tun_dst);
 886         kfree_skb(skb);
 887         return 0;
 888 }
 889
 890 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
 891                 const struct tnl_ptk_info *tpi,
 892                 struct metadata_dst *tun_dst,
 893                 bool log_ecn_err)
 894 {
 895         int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 896                                     const struct ipv6hdr *ipv6h,
 897                                     struct sk_buff *skb);
 898
 899         dscp_ecn_decapsulate = ip6ip6_dscp_ecn_decapsulate;
 900         if (tpi->proto == htons(ETH_P_IP))
 901                 dscp_ecn_decapsulate = ip4ip6_dscp_ecn_decapsulate;
 902
 903         return __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
 904                              log_ecn_err);
 905 }
 906 EXPORT_SYMBOL(ip6_tnl_rcv);
 907
 908 static const struct tnl_ptk_info tpi_v6 = {
 909         /* no tunnel info required for ipxip6. */
 910         .proto = htons(ETH_P_IPV6),
 911 };
 912
 913 static const struct tnl_ptk_info tpi_v4 = {
 914         /* no tunnel info required for ipxip6. */
 915         .proto = htons(ETH_P_IP),
 916 };
 917
 918 static const struct tnl_ptk_info tpi_mpls = {
 919         /* no tunnel info required for mplsip6. */
 920         .proto = htons(ETH_P_MPLS_UC),
 921 };
 922
 923 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
 924                       const struct tnl_ptk_info *tpi,
 925                       int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 926                                                   const struct ipv6hdr *ipv6h,
 927                                                   struct sk_buff *skb))
 928 {
 929         struct ip6_tnl *t;
 930         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 931         struct metadata_dst *tun_dst = NULL;
 932         int ret = -1;
 933
 934         rcu_read_lock();
 935         t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->saddr, &ipv6h->daddr);
 936
 937         if (t) {
 938                 u8 tproto = READ_ONCE(t->parms.proto);
 939
 940                 if (tproto != ipproto && tproto != 0)
 941                         goto drop;
 942                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 943                         goto drop;
 944                 ipv6h = ipv6_hdr(skb);
 945                 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
 946                         goto drop;
 947                 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
 948                         goto drop;
 949                 if (t->parms.collect_md) {
 950                         tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
 951                         if (!tun_dst)
 952                                 goto drop;
 953                 }
 954                 ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
 955                                     log_ecn_error);
 956         }
 957
 958         rcu_read_unlock();
 959
 960         return ret;
 961
 962 drop:
 963         rcu_read_unlock();
 964         kfree_skb(skb);
 965         return 0;
 966 }
 967
 968 static int ip4ip6_rcv(struct sk_buff *skb)
 969 {
 970         return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
 971                           ip4ip6_dscp_ecn_decapsulate);
 972 }
 973
 974 static int ip6ip6_rcv(struct sk_buff *skb)
 975 {
 976         return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
 977                           ip6ip6_dscp_ecn_decapsulate);
 978 }
 979
 980 static int mplsip6_rcv(struct sk_buff *skb)
 981 {
 982         return ipxip6_rcv(skb, IPPROTO_MPLS, &tpi_mpls,
 983                           mplsip6_dscp_ecn_decapsulate);
 984 }
 985
 986 struct ipv6_tel_txoption {
 987         struct ipv6_txoptions ops;
 988         __u8 dst_opt[8];
 989 };
 990
 991 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 992 {
 993         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 994
 995         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 996         opt->dst_opt[3] = 1;
 997         opt->dst_opt[4] = encap_limit;
 998         opt->dst_opt[5] = IPV6_TLV_PADN;
 999         opt->dst_opt[6] = 1;
1000
1001         opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
1002         opt->ops.opt_nflen = 8;
1003 }
1004
1005 /**
1006  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
1007  *   @t: the outgoing tunnel device
1008  *   @hdr: IPv6 header from the incoming packet
1009  *
1010  * Description:
1011  *   Avoid trivial tunneling loop by checking that tunnel exit-point
1012  *   doesn't match source of incoming packet.
1013  *
1014  * Return:
1015  *   1 if conflict,
1016  *   0 else
1017  **/
1018
1019 static inline bool
1020 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
1021 {
1022         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
1023 }
1024
1025 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
1026                      const struct in6_addr *laddr,
1027                      const struct in6_addr *raddr)
1028 {
1029         struct __ip6_tnl_parm *p = &t->parms;
1030         int ret = 0;
1031         struct net *net = t->net;
1032
1033         if (t->parms.collect_md)
1034                 return 1;
1035
1036         if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
1037             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
1038              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
1039                 struct net_device *ldev = NULL;
1040
1041                 rcu_read_lock();
1042                 if (p->link)
1043                         ldev = dev_get_by_index_rcu(net, p->link);
1044
1045                 if (unlikely(!ipv6_chk_addr_and_flags(net, laddr, ldev, false,
1046                                                       0, IFA_F_TENTATIVE)))
1047                         pr_warn_ratelimited("%s xmit: Local address not yet configured!\n",
1048                                             p->name);
1049                 else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
1050                          !ipv6_addr_is_multicast(raddr) &&
1051                          unlikely(ipv6_chk_addr_and_flags(net, raddr, ldev,
1052                                                           true, 0, IFA_F_TENTATIVE)))
1053                         pr_warn_ratelimited("%s xmit: Routing loop! Remote address found on this node!\n",
1054                                             p->name);
1055                 else
1056                         ret = 1;
1057                 rcu_read_unlock();
1058         }
1059         return ret;
1060 }
1061 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1062
1063 /**
1064  * ip6_tnl_xmit - encapsulate packet and send
1065  *   @skb: the outgoing socket buffer
1066  *   @dev: the outgoing tunnel device
1067  *   @dsfield: dscp code for outer header
1068  *   @fl6: flow of tunneled packet
1069  *   @encap_limit: encapsulation limit
1070  *   @pmtu: Path MTU is stored if packet is too big
1071  *   @proto: next header value
1072  *
1073  * Description:
1074  *   Build new header and do some sanity checks on the packet before sending
1075  *   it.
1076  *
1077  * Return:
1078  *   0 on success
1079  *   -1 fail
1080  *   %-EMSGSIZE message too big. return mtu in this case.
1081  **/
1082
1083 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1084                  struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1085                  __u8 proto)
1086 {
1087         struct ip6_tnl *t = netdev_priv(dev);
1088         struct net *net = t->net;
1089         struct net_device_stats *stats = &t->dev->stats;
1090         struct ipv6hdr *ipv6h;
1091         struct ipv6_tel_txoption opt;
1092         struct dst_entry *dst = NULL, *ndst = NULL;
1093         struct net_device *tdev;
1094         int mtu;
1095         unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1096         unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1097         unsigned int max_headroom = psh_hlen;
1098         __be16 payload_protocol;
1099         bool use_cache = false;
1100         u8 hop_limit;
1101         int err = -1;
1102
1103         payload_protocol = skb_protocol(skb, true);
1104
1105         if (t->parms.collect_md) {
1106                 hop_limit = skb_tunnel_info(skb)->key.ttl;
1107                 goto route_lookup;
1108         } else {
1109                 hop_limit = t->parms.hop_limit;
1110         }
1111
1112         /* NBMA tunnel */
1113         if (ipv6_addr_any(&t->parms.raddr)) {
1114                 if (payload_protocol == htons(ETH_P_IPV6)) {
1115                         struct in6_addr *addr6;
1116                         struct neighbour *neigh;
1117                         int addr_type;
1118
1119                         if (!skb_dst(skb))
1120                                 goto tx_err_link_failure;
1121
1122                         neigh = dst_neigh_lookup(skb_dst(skb),
1123                                                  &ipv6_hdr(skb)->daddr);
1124                         if (!neigh)
1125                                 goto tx_err_link_failure;
1126
1127                         addr6 = (struct in6_addr *)&neigh->primary_key;
1128                         addr_type = ipv6_addr_type(addr6);
1129
1130                         if (addr_type == IPV6_ADDR_ANY)
1131                                 addr6 = &ipv6_hdr(skb)->daddr;
1132
1133                         memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1134                         neigh_release(neigh);
1135                 } else if (payload_protocol == htons(ETH_P_IP)) {
1136                         const struct rtable *rt = skb_rtable(skb);
1137
1138                         if (!rt)
1139                                 goto tx_err_link_failure;
1140
1141                         if (rt->rt_gw_family == AF_INET6)
1142                                 memcpy(&fl6->daddr, &rt->rt_gw6, sizeof(fl6->daddr));
1143                 }
1144         } else if (t->parms.proto != 0 && !(t->parms.flags &
1145                                             (IP6_TNL_F_USE_ORIG_TCLASS |
1146                                              IP6_TNL_F_USE_ORIG_FWMARK))) {
1147                 /* enable the cache only if neither the outer protocol nor the
1148                  * routing decision depends on the current inner header value
1149                  */
1150                 use_cache = true;
1151         }
1152
1153         if (use_cache)
1154                 dst = dst_cache_get(&t->dst_cache);
1155
1156         if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1157                 goto tx_err_link_failure;
1158
1159         if (!dst) {
1160 route_lookup:
1161                 /* add dsfield to flowlabel for route lookup */
1162                 fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1163
1164                 dst = ip6_route_output(net, NULL, fl6);
1165
1166                 if (dst->error)
1167                         goto tx_err_link_failure;
1168                 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1169                 if (IS_ERR(dst)) {
1170                         err = PTR_ERR(dst);
1171                         dst = NULL;
1172                         goto tx_err_link_failure;
1173                 }
1174                 if (t->parms.collect_md && ipv6_addr_any(&fl6->saddr) &&
1175                     ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1176                                        &fl6->daddr, 0, &fl6->saddr))
1177                         goto tx_err_link_failure;
1178                 ndst = dst;
1179         }
1180
1181         tdev = dst->dev;
1182
1183         if (tdev == dev) {
1184                 stats->collisions++;
1185                 net_warn_ratelimited("%s: Local routing loop detected!\n",
1186                                      t->parms.name);
1187                 goto tx_err_dst_release;
1188         }
1189         mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
1190         if (encap_limit >= 0) {
1191                 max_headroom += 8;
1192                 mtu -= 8;
1193         }
1194         mtu = max(mtu, skb->protocol == htons(ETH_P_IPV6) ?
1195                        IPV6_MIN_MTU : IPV4_MIN_MTU);
1196
1197         skb_dst_update_pmtu_no_confirm(skb, mtu);
1198         if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
1199                 *pmtu = mtu;
1200                 err = -EMSGSIZE;
1201                 goto tx_err_dst_release;
1202         }
1203
1204         if (t->err_count > 0) {
1205                 if (time_before(jiffies,
1206                                 t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1207                         t->err_count--;
1208
1209                         dst_link_failure(skb);
1210                 } else {
1211                         t->err_count = 0;
1212                 }
1213         }
1214
1215         skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1216
1217         /*
1218          * Okay, now see if we can stuff it in the buffer as-is.
1219          */
1220         max_headroom += LL_RESERVED_SPACE(tdev);
1221
1222         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1223             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1224                 struct sk_buff *new_skb;
1225
1226                 new_skb = skb_realloc_headroom(skb, max_headroom);
1227                 if (!new_skb)
1228                         goto tx_err_dst_release;
1229
1230                 if (skb->sk)
1231                         skb_set_owner_w(new_skb, skb->sk);
1232                 consume_skb(skb);
1233                 skb = new_skb;
1234         }
1235
1236         if (t->parms.collect_md) {
1237                 if (t->encap.type != TUNNEL_ENCAP_NONE)
1238                         goto tx_err_dst_release;
1239         } else {
1240                 if (use_cache && ndst)
1241                         dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1242         }
1243         skb_dst_set(skb, dst);
1244
1245         if (hop_limit == 0) {
1246                 if (payload_protocol == htons(ETH_P_IP))
1247                         hop_limit = ip_hdr(skb)->ttl;
1248                 else if (payload_protocol == htons(ETH_P_IPV6))
1249                         hop_limit = ipv6_hdr(skb)->hop_limit;
1250                 else
1251                         hop_limit = ip6_dst_hoplimit(dst);
1252         }
1253
1254         /* Calculate max headroom for all the headers and adjust
1255          * needed_headroom if necessary.
1256          */
1257         max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1258                         + dst->header_len + t->hlen;
1259         if (max_headroom > READ_ONCE(dev->needed_headroom))
1260                 WRITE_ONCE(dev->needed_headroom, max_headroom);
1261
1262         err = ip6_tnl_encap(skb, t, &proto, fl6);
1263         if (err)
1264                 return err;
1265
1266         if (encap_limit >= 0) {
1267                 init_tel_txopt(&opt, encap_limit);
1268                 ipv6_push_frag_opts(skb, &opt.ops, &proto);
1269         }
1270
1271         skb_push(skb, sizeof(struct ipv6hdr));
1272         skb_reset_network_header(skb);
1273         ipv6h = ipv6_hdr(skb);
1274         ip6_flow_hdr(ipv6h, dsfield,
1275                      ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1276         ipv6h->hop_limit = hop_limit;
1277         ipv6h->nexthdr = proto;
1278         ipv6h->saddr = fl6->saddr;
1279         ipv6h->daddr = fl6->daddr;
1280         ip6tunnel_xmit(NULL, skb, dev);
1281         return 0;
1282 tx_err_link_failure:
1283         stats->tx_carrier_errors++;
1284         dst_link_failure(skb);
1285 tx_err_dst_release:
1286         dst_release(dst);
1287         return err;
1288 }
1289 EXPORT_SYMBOL(ip6_tnl_xmit);
1290
1291 static inline int
1292 ipxip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev,
1293                 u8 protocol)
1294 {
1295         struct ip6_tnl *t = netdev_priv(dev);
1296         struct ipv6hdr *ipv6h;
1297         const struct iphdr  *iph;
1298         int encap_limit = -1;
1299         __u16 offset;
1300         struct flowi6 fl6;
1301         __u8 dsfield, orig_dsfield;
1302         __u32 mtu;
1303         u8 tproto;
1304         int err;
1305
1306         tproto = READ_ONCE(t->parms.proto);
1307         if (tproto != protocol && tproto != 0)
1308                 return -1;
1309
1310         if (t->parms.collect_md) {
1311                 struct ip_tunnel_info *tun_info;
1312                 const struct ip_tunnel_key *key;
1313
1314                 tun_info = skb_tunnel_info(skb);
1315                 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1316                              ip_tunnel_info_af(tun_info) != AF_INET6))
1317                         return -1;
1318                 key = &tun_info->key;
1319                 memset(&fl6, 0, sizeof(fl6));
1320                 fl6.flowi6_proto = protocol;
1321                 fl6.saddr = key->u.ipv6.src;
1322                 fl6.daddr = key->u.ipv6.dst;
1323                 fl6.flowlabel = key->label;
1324                 dsfield =  key->tos;
1325                 switch (protocol) {
1326                 case IPPROTO_IPIP:
1327                         iph = ip_hdr(skb);
1328                         orig_dsfield = ipv4_get_dsfield(iph);
1329                         break;
1330                 case IPPROTO_IPV6:
1331                         ipv6h = ipv6_hdr(skb);
1332                         orig_dsfield = ipv6_get_dsfield(ipv6h);
1333                         break;
1334                 default:
1335                         orig_dsfield = dsfield;
1336                         break;
1337                 }
1338         } else {
1339                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1340                         encap_limit = t->parms.encap_limit;
1341                 if (protocol == IPPROTO_IPV6) {
1342                         offset = ip6_tnl_parse_tlv_enc_lim(skb,
1343                                                 skb_network_header(skb));
1344                         /* ip6_tnl_parse_tlv_enc_lim() might have
1345                          * reallocated skb->head
1346                          */
1347                         if (offset > 0) {
1348                                 struct ipv6_tlv_tnl_enc_lim *tel;
1349
1350                                 tel = (void *)&skb_network_header(skb)[offset];
1351                                 if (tel->encap_limit == 0) {
1352                                         icmpv6_ndo_send(skb, ICMPV6_PARAMPROB,
1353                                                         ICMPV6_HDR_FIELD, offset + 2);
1354                                         return -1;
1355                                 }
1356                                 encap_limit = tel->encap_limit - 1;
1357                         }
1358                 }
1359
1360                 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1361                 fl6.flowi6_proto = protocol;
1362
1363                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1364                         fl6.flowi6_mark = skb->mark;
1365                 else
1366                         fl6.flowi6_mark = t->parms.fwmark;
1367                 switch (protocol) {
1368                 case IPPROTO_IPIP:
1369                         iph = ip_hdr(skb);
1370                         orig_dsfield = ipv4_get_dsfield(iph);
1371                         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1372                                 dsfield = orig_dsfield;
1373                         else
1374                                 dsfield = ip6_tclass(t->parms.flowinfo);
1375                         break;
1376                 case IPPROTO_IPV6:
1377                         ipv6h = ipv6_hdr(skb);
1378                         orig_dsfield = ipv6_get_dsfield(ipv6h);
1379                         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1380                                 dsfield = orig_dsfield;
1381                         else
1382                                 dsfield = ip6_tclass(t->parms.flowinfo);
1383                         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1384                                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
1385                         break;
1386                 default:
1387                         orig_dsfield = dsfield = ip6_tclass(t->parms.flowinfo);
1388                         break;
1389                 }
1390         }
1391
1392         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1393         dsfield = INET_ECN_encapsulate(dsfield, orig_dsfield);
1394
1395         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1396                 return -1;
1397
1398         skb_set_inner_ipproto(skb, protocol);
1399
1400         err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1401                            protocol);
1402         if (err != 0) {
1403                 /* XXX: send ICMP error even if DF is not set. */
1404                 if (err == -EMSGSIZE)
1405                         switch (protocol) {
1406                         case IPPROTO_IPIP:
1407                                 icmp_ndo_send(skb, ICMP_DEST_UNREACH,
1408                                               ICMP_FRAG_NEEDED, htonl(mtu));
1409                                 break;
1410                         case IPPROTO_IPV6:
1411                                 icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1412                                 break;
1413                         default:
1414                                 break;
1415                         }
1416                 return -1;
1417         }
1418
1419         return 0;
1420 }
1421
1422 static netdev_tx_t
1423 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1424 {
1425         struct ip6_tnl *t = netdev_priv(dev);
1426         struct net_device_stats *stats = &t->dev->stats;
1427         u8 ipproto;
1428         int ret;
1429
1430         if (!pskb_inet_may_pull(skb))
1431                 goto tx_err;
1432
1433         switch (skb->protocol) {
1434         case htons(ETH_P_IP):
1435                 ipproto = IPPROTO_IPIP;
1436                 break;
1437         case htons(ETH_P_IPV6):
1438                 if (ip6_tnl_addr_conflict(t, ipv6_hdr(skb)))
1439                         goto tx_err;
1440                 ipproto = IPPROTO_IPV6;
1441                 break;
1442         case htons(ETH_P_MPLS_UC):
1443                 ipproto = IPPROTO_MPLS;
1444                 break;
1445         default:
1446                 goto tx_err;
1447         }
1448
1449         ret = ipxip6_tnl_xmit(skb, dev, ipproto);
1450         if (ret < 0)
1451                 goto tx_err;
1452
1453         return NETDEV_TX_OK;
1454
1455 tx_err:
1456         stats->tx_errors++;
1457         stats->tx_dropped++;
1458         kfree_skb(skb);
1459         return NETDEV_TX_OK;
1460 }
1461
1462 static void ip6_tnl_link_config(struct ip6_tnl *t)
1463 {
1464         struct net_device *dev = t->dev;
1465         struct net_device *tdev = NULL;
1466         struct __ip6_tnl_parm *p = &t->parms;
1467         struct flowi6 *fl6 = &t->fl.u.ip6;
1468         int t_hlen;
1469         int mtu;
1470
1471         __dev_addr_set(dev, &p->laddr, sizeof(struct in6_addr));
1472         memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1473
1474         /* Set up flowi template */
1475         fl6->saddr = p->laddr;
1476         fl6->daddr = p->raddr;
1477         fl6->flowi6_oif = p->link;
1478         fl6->flowlabel = 0;
1479
1480         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1481                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1482         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1483                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1484
1485         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1486         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1487
1488         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1489                 dev->flags |= IFF_POINTOPOINT;
1490         else
1491                 dev->flags &= ~IFF_POINTOPOINT;
1492
1493         t->tun_hlen = 0;
1494         t->hlen = t->encap_hlen + t->tun_hlen;
1495         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1496
1497         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1498                 int strict = (ipv6_addr_type(&p->raddr) &
1499                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1500
1501                 struct rt6_info *rt = rt6_lookup(t->net,
1502                                                  &p->raddr, &p->laddr,
1503                                                  p->link, NULL, strict);
1504                 if (rt) {
1505                         tdev = rt->dst.dev;
1506                         ip6_rt_put(rt);
1507                 }
1508
1509                 if (!tdev && p->link)
1510                         tdev = __dev_get_by_index(t->net, p->link);
1511
1512                 if (tdev) {
1513                         dev->hard_header_len = tdev->hard_header_len + t_hlen;
1514                         mtu = min_t(unsigned int, tdev->mtu, IP6_MAX_MTU);
1515
1516                         mtu = mtu - t_hlen;
1517                         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1518                                 mtu -= 8;
1519
1520                         if (mtu < IPV6_MIN_MTU)
1521                                 mtu = IPV6_MIN_MTU;
1522                         WRITE_ONCE(dev->mtu, mtu);
1523                 }
1524         }
1525 }
1526
1527 /**
1528  * ip6_tnl_change - update the tunnel parameters
1529  *   @t: tunnel to be changed
1530  *   @p: tunnel configuration parameters
1531  *
1532  * Description:
1533  *   ip6_tnl_change() updates the tunnel parameters
1534  **/
1535
1536 static void
1537 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1538 {
1539         t->parms.laddr = p->laddr;
1540         t->parms.raddr = p->raddr;
1541         t->parms.flags = p->flags;
1542         t->parms.hop_limit = p->hop_limit;
1543         t->parms.encap_limit = p->encap_limit;
1544         t->parms.flowinfo = p->flowinfo;
1545         t->parms.link = p->link;
1546         t->parms.proto = p->proto;
1547         t->parms.fwmark = p->fwmark;
1548         dst_cache_reset(&t->dst_cache);
1549         ip6_tnl_link_config(t);
1550 }
1551
1552 static void ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1553 {
1554         struct net *net = t->net;
1555         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1556
1557         ip6_tnl_unlink(ip6n, t);
1558         synchronize_net();
1559         ip6_tnl_change(t, p);
1560         ip6_tnl_link(ip6n, t);
1561         netdev_state_change(t->dev);
1562 }
1563
1564 static void ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1565 {
1566         /* for default tnl0 device allow to change only the proto */
1567         t->parms.proto = p->proto;
1568         netdev_state_change(t->dev);
1569 }
1570
1571 static void
1572 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1573 {
1574         p->laddr = u->laddr;
1575         p->raddr = u->raddr;
1576         p->flags = u->flags;
1577         p->hop_limit = u->hop_limit;
1578         p->encap_limit = u->encap_limit;
1579         p->flowinfo = u->flowinfo;
1580         p->link = u->link;
1581         p->proto = u->proto;
1582         memcpy(p->name, u->name, sizeof(u->name));
1583 }
1584
1585 static void
1586 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1587 {
1588         u->laddr = p->laddr;
1589         u->raddr = p->raddr;
1590         u->flags = p->flags;
1591         u->hop_limit = p->hop_limit;
1592         u->encap_limit = p->encap_limit;
1593         u->flowinfo = p->flowinfo;
1594         u->link = p->link;
1595         u->proto = p->proto;
1596         memcpy(u->name, p->name, sizeof(u->name));
1597 }
1598
1599 /**
1600  * ip6_tnl_siocdevprivate - configure ipv6 tunnels from userspace
1601  *   @dev: virtual device associated with tunnel
1602  *   @ifr: unused
1603  *   @data: parameters passed from userspace
1604  *   @cmd: command to be performed
1605  *
1606  * Description:
1607  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1608  *   from userspace.
1609  *
1610  *   The possible commands are the following:
1611  *     %SIOCGETTUNNEL: get tunnel parameters for device
1612  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1613  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1614  *     %SIOCDELTUNNEL: delete tunnel
1615  *
1616  *   The fallback device "ip6tnl0", created during module
1617  *   initialization, can be used for creating other tunnel devices.
1618  *
1619  * Return:
1620  *   0 on success,
1621  *   %-EFAULT if unable to copy data to or from userspace,
1622  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1623  *   %-EINVAL if passed tunnel parameters are invalid,
1624  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1625  *   %-ENODEV if attempting to change or delete a nonexisting device
1626  **/
1627
1628 static int
1629 ip6_tnl_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
1630                        void __user *data, int cmd)
1631 {
1632         int err = 0;
1633         struct ip6_tnl_parm p;
1634         struct __ip6_tnl_parm p1;
1635         struct ip6_tnl *t = netdev_priv(dev);
1636         struct net *net = t->net;
1637         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1638
1639         memset(&p1, 0, sizeof(p1));
1640
1641         switch (cmd) {
1642         case SIOCGETTUNNEL:
1643                 if (dev == ip6n->fb_tnl_dev) {
1644                         if (copy_from_user(&p, data, sizeof(p))) {
1645                                 err = -EFAULT;
1646                                 break;
1647                         }
1648                         ip6_tnl_parm_from_user(&p1, &p);
1649                         t = ip6_tnl_locate(net, &p1, 0);
1650                         if (IS_ERR(t))
1651                                 t = netdev_priv(dev);
1652                 } else {
1653                         memset(&p, 0, sizeof(p));
1654                 }
1655                 ip6_tnl_parm_to_user(&p, &t->parms);
1656                 if (copy_to_user(data, &p, sizeof(p)))
1657                         err = -EFAULT;
1658                 break;
1659         case SIOCADDTUNNEL:
1660         case SIOCCHGTUNNEL:
1661                 err = -EPERM;
1662                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1663                         break;
1664                 err = -EFAULT;
1665                 if (copy_from_user(&p, data, sizeof(p)))
1666                         break;
1667                 err = -EINVAL;
1668                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1669                     p.proto != 0)
1670                         break;
1671                 ip6_tnl_parm_from_user(&p1, &p);
1672                 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1673                 if (cmd == SIOCCHGTUNNEL) {
1674                         if (!IS_ERR(t)) {
1675                                 if (t->dev != dev) {
1676                                         err = -EEXIST;
1677                                         break;
1678                                 }
1679                         } else
1680                                 t = netdev_priv(dev);
1681                         if (dev == ip6n->fb_tnl_dev)
1682                                 ip6_tnl0_update(t, &p1);
1683                         else
1684                                 ip6_tnl_update(t, &p1);
1685                 }
1686                 if (!IS_ERR(t)) {
1687                         err = 0;
1688                         ip6_tnl_parm_to_user(&p, &t->parms);
1689                         if (copy_to_user(data, &p, sizeof(p)))
1690                                 err = -EFAULT;
1691
1692                 } else {
1693                         err = PTR_ERR(t);
1694                 }
1695                 break;
1696         case SIOCDELTUNNEL:
1697                 err = -EPERM;
1698                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1699                         break;
1700
1701                 if (dev == ip6n->fb_tnl_dev) {
1702                         err = -EFAULT;
1703                         if (copy_from_user(&p, data, sizeof(p)))
1704                                 break;
1705                         err = -ENOENT;
1706                         ip6_tnl_parm_from_user(&p1, &p);
1707                         t = ip6_tnl_locate(net, &p1, 0);
1708                         if (IS_ERR(t))
1709                                 break;
1710                         err = -EPERM;
1711                         if (t->dev == ip6n->fb_tnl_dev)
1712                                 break;
1713                         dev = t->dev;
1714                 }
1715                 err = 0;
1716                 unregister_netdevice(dev);
1717                 break;
1718         default:
1719                 err = -EINVAL;
1720         }
1721         return err;
1722 }
1723
1724 /**
1725  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1726  *   @dev: virtual device associated with tunnel
1727  *   @new_mtu: the new mtu
1728  *
1729  * Return:
1730  *   0 on success,
1731  *   %-EINVAL if mtu too small
1732  **/
1733
1734 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1735 {
1736         struct ip6_tnl *tnl = netdev_priv(dev);
1737
1738         if (tnl->parms.proto == IPPROTO_IPV6) {
1739                 if (new_mtu < IPV6_MIN_MTU)
1740                         return -EINVAL;
1741         } else {
1742                 if (new_mtu < ETH_MIN_MTU)
1743                         return -EINVAL;
1744         }
1745         if (tnl->parms.proto == IPPROTO_IPV6 || tnl->parms.proto == 0) {
1746                 if (new_mtu > IP6_MAX_MTU - dev->hard_header_len)
1747                         return -EINVAL;
1748         } else {
1749                 if (new_mtu > IP_MAX_MTU - dev->hard_header_len)
1750                         return -EINVAL;
1751         }
1752         dev->mtu = new_mtu;
1753         return 0;
1754 }
1755 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1756
1757 int ip6_tnl_get_iflink(const struct net_device *dev)
1758 {
1759         struct ip6_tnl *t = netdev_priv(dev);
1760
1761         return t->parms.link;
1762 }
1763 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1764
1765 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1766                           unsigned int num)
1767 {
1768         if (num >= MAX_IPTUN_ENCAP_OPS)
1769                 return -ERANGE;
1770
1771         return !cmpxchg((const struct ip6_tnl_encap_ops **)
1772                         &ip6tun_encaps[num],
1773                         NULL, ops) ? 0 : -1;
1774 }
1775 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1776
1777 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1778                           unsigned int num)
1779 {
1780         int ret;
1781
1782         if (num >= MAX_IPTUN_ENCAP_OPS)
1783                 return -ERANGE;
1784
1785         ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1786                        &ip6tun_encaps[num],
1787                        ops, NULL) == ops) ? 0 : -1;
1788
1789         synchronize_net();
1790
1791         return ret;
1792 }
1793 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1794
1795 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1796                         struct ip_tunnel_encap *ipencap)
1797 {
1798         int hlen;
1799
1800         memset(&t->encap, 0, sizeof(t->encap));
1801
1802         hlen = ip6_encap_hlen(ipencap);
1803         if (hlen < 0)
1804                 return hlen;
1805
1806         t->encap.type = ipencap->type;
1807         t->encap.sport = ipencap->sport;
1808         t->encap.dport = ipencap->dport;
1809         t->encap.flags = ipencap->flags;
1810
1811         t->encap_hlen = hlen;
1812         t->hlen = t->encap_hlen + t->tun_hlen;
1813
1814         return 0;
1815 }
1816 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1817
1818 static const struct net_device_ops ip6_tnl_netdev_ops = {
1819         .ndo_init       = ip6_tnl_dev_init,
1820         .ndo_uninit     = ip6_tnl_dev_uninit,
1821         .ndo_start_xmit = ip6_tnl_start_xmit,
1822         .ndo_siocdevprivate = ip6_tnl_siocdevprivate,
1823         .ndo_change_mtu = ip6_tnl_change_mtu,
1824         .ndo_get_stats64 = dev_get_tstats64,
1825         .ndo_get_iflink = ip6_tnl_get_iflink,
1826 };
1827
1828 #define IPXIPX_FEATURES (NETIF_F_SG |           \
1829                          NETIF_F_FRAGLIST |     \
1830                          NETIF_F_HIGHDMA |      \
1831                          NETIF_F_GSO_SOFTWARE | \
1832                          NETIF_F_HW_CSUM)
1833
1834 /**
1835  * ip6_tnl_dev_setup - setup virtual tunnel device
1836  *   @dev: virtual device associated with tunnel
1837  *
1838  * Description:
1839  *   Initialize function pointers and device parameters
1840  **/
1841
1842 static void ip6_tnl_dev_setup(struct net_device *dev)
1843 {
1844         dev->netdev_ops = &ip6_tnl_netdev_ops;
1845         dev->header_ops = &ip_tunnel_header_ops;
1846         dev->needs_free_netdev = true;
1847         dev->priv_destructor = ip6_dev_free;
1848
1849         dev->type = ARPHRD_TUNNEL6;
1850         dev->flags |= IFF_NOARP;
1851         dev->addr_len = sizeof(struct in6_addr);
1852         dev->features |= NETIF_F_LLTX;
1853         netif_keep_dst(dev);
1854
1855         dev->features           |= IPXIPX_FEATURES;
1856         dev->hw_features        |= IPXIPX_FEATURES;
1857
1858         /* This perm addr will be used as interface identifier by IPv6 */
1859         dev->addr_assign_type = NET_ADDR_RANDOM;
1860         eth_random_addr(dev->perm_addr);
1861 }
1862
1863
1864 /**
1865  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1866  *   @dev: virtual device associated with tunnel
1867  **/
1868
1869 static inline int
1870 ip6_tnl_dev_init_gen(struct net_device *dev)
1871 {
1872         struct ip6_tnl *t = netdev_priv(dev);
1873         int ret;
1874         int t_hlen;
1875
1876         t->dev = dev;
1877         t->net = dev_net(dev);
1878         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1879         if (!dev->tstats)
1880                 return -ENOMEM;
1881
1882         ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1883         if (ret)
1884                 goto free_stats;
1885
1886         ret = gro_cells_init(&t->gro_cells, dev);
1887         if (ret)
1888                 goto destroy_dst;
1889
1890         t->tun_hlen = 0;
1891         t->hlen = t->encap_hlen + t->tun_hlen;
1892         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1893
1894         dev->type = ARPHRD_TUNNEL6;
1895         dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1896         dev->mtu = ETH_DATA_LEN - t_hlen;
1897         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1898                 dev->mtu -= 8;
1899         dev->min_mtu = ETH_MIN_MTU;
1900         dev->max_mtu = IP6_MAX_MTU - dev->hard_header_len;
1901
1902         netdev_hold(dev, &t->dev_tracker, GFP_KERNEL);
1903         return 0;
1904
1905 destroy_dst:
1906         dst_cache_destroy(&t->dst_cache);
1907 free_stats:
1908         free_percpu(dev->tstats);
1909         dev->tstats = NULL;
1910
1911         return ret;
1912 }
1913
1914 /**
1915  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1916  *   @dev: virtual device associated with tunnel
1917  **/
1918
1919 static int ip6_tnl_dev_init(struct net_device *dev)
1920 {
1921         struct ip6_tnl *t = netdev_priv(dev);
1922         int err = ip6_tnl_dev_init_gen(dev);
1923
1924         if (err)
1925                 return err;
1926         ip6_tnl_link_config(t);
1927         if (t->parms.collect_md)
1928                 netif_keep_dst(dev);
1929         return 0;
1930 }
1931
1932 /**
1933  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1934  *   @dev: fallback device
1935  *
1936  * Return: 0
1937  **/
1938
1939 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1940 {
1941         struct ip6_tnl *t = netdev_priv(dev);
1942         struct net *net = dev_net(dev);
1943         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1944
1945         t->parms.proto = IPPROTO_IPV6;
1946
1947         rcu_assign_pointer(ip6n->tnls_wc[0], t);
1948         return 0;
1949 }
1950
1951 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[],
1952                             struct netlink_ext_ack *extack)
1953 {
1954         u8 proto;
1955
1956         if (!data || !data[IFLA_IPTUN_PROTO])
1957                 return 0;
1958
1959         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1960         if (proto != IPPROTO_IPV6 &&
1961             proto != IPPROTO_IPIP &&
1962             proto != 0)
1963                 return -EINVAL;
1964
1965         return 0;
1966 }
1967
1968 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1969                                   struct __ip6_tnl_parm *parms)
1970 {
1971         memset(parms, 0, sizeof(*parms));
1972
1973         if (!data)
1974                 return;
1975
1976         if (data[IFLA_IPTUN_LINK])
1977                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1978
1979         if (data[IFLA_IPTUN_LOCAL])
1980                 parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1981
1982         if (data[IFLA_IPTUN_REMOTE])
1983                 parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1984
1985         if (data[IFLA_IPTUN_TTL])
1986                 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1987
1988         if (data[IFLA_IPTUN_ENCAP_LIMIT])
1989                 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1990
1991         if (data[IFLA_IPTUN_FLOWINFO])
1992                 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1993
1994         if (data[IFLA_IPTUN_FLAGS])
1995                 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1996
1997         if (data[IFLA_IPTUN_PROTO])
1998                 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1999
2000         if (data[IFLA_IPTUN_COLLECT_METADATA])
2001                 parms->collect_md = true;
2002
2003         if (data[IFLA_IPTUN_FWMARK])
2004                 parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
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 (ip_tunnel_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 (ip_tunnel_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         ip6_tnl_update(t, &p);
2074         return 0;
2075 }
2076
2077 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2078 {
2079         struct net *net = dev_net(dev);
2080         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2081
2082         if (dev != ip6n->fb_tnl_dev)
2083                 unregister_netdevice_queue(dev, head);
2084 }
2085
2086 static size_t ip6_tnl_get_size(const struct net_device *dev)
2087 {
2088         return
2089                 /* IFLA_IPTUN_LINK */
2090                 nla_total_size(4) +
2091                 /* IFLA_IPTUN_LOCAL */
2092                 nla_total_size(sizeof(struct in6_addr)) +
2093                 /* IFLA_IPTUN_REMOTE */
2094                 nla_total_size(sizeof(struct in6_addr)) +
2095                 /* IFLA_IPTUN_TTL */
2096                 nla_total_size(1) +
2097                 /* IFLA_IPTUN_ENCAP_LIMIT */
2098                 nla_total_size(1) +
2099                 /* IFLA_IPTUN_FLOWINFO */
2100                 nla_total_size(4) +
2101                 /* IFLA_IPTUN_FLAGS */
2102                 nla_total_size(4) +
2103                 /* IFLA_IPTUN_PROTO */
2104                 nla_total_size(1) +
2105                 /* IFLA_IPTUN_ENCAP_TYPE */
2106                 nla_total_size(2) +
2107                 /* IFLA_IPTUN_ENCAP_FLAGS */
2108                 nla_total_size(2) +
2109                 /* IFLA_IPTUN_ENCAP_SPORT */
2110                 nla_total_size(2) +
2111                 /* IFLA_IPTUN_ENCAP_DPORT */
2112                 nla_total_size(2) +
2113                 /* IFLA_IPTUN_COLLECT_METADATA */
2114                 nla_total_size(0) +
2115                 /* IFLA_IPTUN_FWMARK */
2116                 nla_total_size(4) +
2117                 0;
2118 }
2119
2120 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2121 {
2122         struct ip6_tnl *tunnel = netdev_priv(dev);
2123         struct __ip6_tnl_parm *parm = &tunnel->parms;
2124
2125         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2126             nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2127             nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2128             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2129             nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2130             nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2131             nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2132             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
2133             nla_put_u32(skb, IFLA_IPTUN_FWMARK, parm->fwmark))
2134                 goto nla_put_failure;
2135
2136         if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2137             nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2138             nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2139             nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2140                 goto nla_put_failure;
2141
2142         if (parm->collect_md)
2143                 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2144                         goto nla_put_failure;
2145
2146         return 0;
2147
2148 nla_put_failure:
2149         return -EMSGSIZE;
2150 }
2151
2152 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2153 {
2154         struct ip6_tnl *tunnel = netdev_priv(dev);
2155
2156         return tunnel->net;
2157 }
2158 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2159
2160 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2161         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
2162         [IFLA_IPTUN_LOCAL]              = { .len = sizeof(struct in6_addr) },
2163         [IFLA_IPTUN_REMOTE]             = { .len = sizeof(struct in6_addr) },
2164         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
2165         [IFLA_IPTUN_ENCAP_LIMIT]        = { .type = NLA_U8 },
2166         [IFLA_IPTUN_FLOWINFO]           = { .type = NLA_U32 },
2167         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U32 },
2168         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
2169         [IFLA_IPTUN_ENCAP_TYPE]         = { .type = NLA_U16 },
2170         [IFLA_IPTUN_ENCAP_FLAGS]        = { .type = NLA_U16 },
2171         [IFLA_IPTUN_ENCAP_SPORT]        = { .type = NLA_U16 },
2172         [IFLA_IPTUN_ENCAP_DPORT]        = { .type = NLA_U16 },
2173         [IFLA_IPTUN_COLLECT_METADATA]   = { .type = NLA_FLAG },
2174         [IFLA_IPTUN_FWMARK]             = { .type = NLA_U32 },
2175 };
2176
2177 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2178         .kind           = "ip6tnl",
2179         .maxtype        = IFLA_IPTUN_MAX,
2180         .policy         = ip6_tnl_policy,
2181         .priv_size      = sizeof(struct ip6_tnl),
2182         .setup          = ip6_tnl_dev_setup,
2183         .validate       = ip6_tnl_validate,
2184         .newlink        = ip6_tnl_newlink,
2185         .changelink     = ip6_tnl_changelink,
2186         .dellink        = ip6_tnl_dellink,
2187         .get_size       = ip6_tnl_get_size,
2188         .fill_info      = ip6_tnl_fill_info,
2189         .get_link_net   = ip6_tnl_get_link_net,
2190 };
2191
2192 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2193         .handler        = ip4ip6_rcv,
2194         .err_handler    = ip4ip6_err,
2195         .priority       =       1,
2196 };
2197
2198 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2199         .handler        = ip6ip6_rcv,
2200         .err_handler    = ip6ip6_err,
2201         .priority       =       1,
2202 };
2203
2204 static struct xfrm6_tunnel mplsip6_handler __read_mostly = {
2205         .handler        = mplsip6_rcv,
2206         .err_handler    = mplsip6_err,
2207         .priority       =       1,
2208 };
2209
2210 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net, struct list_head *list)
2211 {
2212         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2213         struct net_device *dev, *aux;
2214         int h;
2215         struct ip6_tnl *t;
2216
2217         for_each_netdev_safe(net, dev, aux)
2218                 if (dev->rtnl_link_ops == &ip6_link_ops)
2219                         unregister_netdevice_queue(dev, list);
2220
2221         for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2222                 t = rtnl_dereference(ip6n->tnls_r_l[h]);
2223                 while (t) {
2224                         /* If dev is in the same netns, it has already
2225                          * been added to the list by the previous loop.
2226                          */
2227                         if (!net_eq(dev_net(t->dev), net))
2228                                 unregister_netdevice_queue(t->dev, list);
2229                         t = rtnl_dereference(t->next);
2230                 }
2231         }
2232
2233         t = rtnl_dereference(ip6n->tnls_wc[0]);
2234         while (t) {
2235                 /* If dev is in the same netns, it has already
2236                  * been added to the list by the previous loop.
2237                  */
2238                 if (!net_eq(dev_net(t->dev), net))
2239                         unregister_netdevice_queue(t->dev, list);
2240                 t = rtnl_dereference(t->next);
2241         }
2242 }
2243
2244 static int __net_init ip6_tnl_init_net(struct net *net)
2245 {
2246         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2247         struct ip6_tnl *t = NULL;
2248         int err;
2249
2250         ip6n->tnls[0] = ip6n->tnls_wc;
2251         ip6n->tnls[1] = ip6n->tnls_r_l;
2252
2253         if (!net_has_fallback_tunnels(net))
2254                 return 0;
2255         err = -ENOMEM;
2256         ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2257                                         NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2258
2259         if (!ip6n->fb_tnl_dev)
2260                 goto err_alloc_dev;
2261         dev_net_set(ip6n->fb_tnl_dev, net);
2262         ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2263         /* FB netdevice is special: we have one, and only one per netns.
2264          * Allowing to move it to another netns is clearly unsafe.
2265          */
2266         ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2267
2268         err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2269         if (err < 0)
2270                 goto err_register;
2271
2272         err = register_netdev(ip6n->fb_tnl_dev);
2273         if (err < 0)
2274                 goto err_register;
2275
2276         t = netdev_priv(ip6n->fb_tnl_dev);
2277
2278         strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2279         return 0;
2280
2281 err_register:
2282         free_netdev(ip6n->fb_tnl_dev);
2283 err_alloc_dev:
2284         return err;
2285 }
2286
2287 static void __net_exit ip6_tnl_exit_batch_net(struct list_head *net_list)
2288 {
2289         struct net *net;
2290         LIST_HEAD(list);
2291
2292         rtnl_lock();
2293         list_for_each_entry(net, net_list, exit_list)
2294                 ip6_tnl_destroy_tunnels(net, &list);
2295         unregister_netdevice_many(&list);
2296         rtnl_unlock();
2297 }
2298
2299 static struct pernet_operations ip6_tnl_net_ops = {
2300         .init = ip6_tnl_init_net,
2301         .exit_batch = ip6_tnl_exit_batch_net,
2302         .id   = &ip6_tnl_net_id,
2303         .size = sizeof(struct ip6_tnl_net),
2304 };
2305
2306 /**
2307  * ip6_tunnel_init - register protocol and reserve needed resources
2308  *
2309  * Return: 0 on success
2310  **/
2311
2312 static int __init ip6_tunnel_init(void)
2313 {
2314         int  err;
2315
2316         if (!ipv6_mod_enabled())
2317                 return -EOPNOTSUPP;
2318
2319         err = register_pernet_device(&ip6_tnl_net_ops);
2320         if (err < 0)
2321                 goto out_pernet;
2322
2323         err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2324         if (err < 0) {
2325                 pr_err("%s: can't register ip4ip6\n", __func__);
2326                 goto out_ip4ip6;
2327         }
2328
2329         err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2330         if (err < 0) {
2331                 pr_err("%s: can't register ip6ip6\n", __func__);
2332                 goto out_ip6ip6;
2333         }
2334
2335         if (ip6_tnl_mpls_supported()) {
2336                 err = xfrm6_tunnel_register(&mplsip6_handler, AF_MPLS);
2337                 if (err < 0) {
2338                         pr_err("%s: can't register mplsip6\n", __func__);
2339                         goto out_mplsip6;
2340                 }
2341         }
2342
2343         err = rtnl_link_register(&ip6_link_ops);
2344         if (err < 0)
2345                 goto rtnl_link_failed;
2346
2347         return 0;
2348
2349 rtnl_link_failed:
2350         if (ip6_tnl_mpls_supported())
2351                 xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS);
2352 out_mplsip6:
2353         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2354 out_ip6ip6:
2355         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2356 out_ip4ip6:
2357         unregister_pernet_device(&ip6_tnl_net_ops);
2358 out_pernet:
2359         return err;
2360 }
2361
2362 /**
2363  * ip6_tunnel_cleanup - free resources and unregister protocol
2364  **/
2365
2366 static void __exit ip6_tunnel_cleanup(void)
2367 {
2368         rtnl_link_unregister(&ip6_link_ops);
2369         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2370                 pr_info("%s: can't deregister ip4ip6\n", __func__);
2371
2372         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2373                 pr_info("%s: can't deregister ip6ip6\n", __func__);
2374
2375         if (ip6_tnl_mpls_supported() &&
2376             xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS))
2377                 pr_info("%s: can't deregister mplsip6\n", __func__);
2378         unregister_pernet_device(&ip6_tnl_net_ops);
2379 }
2380
2381 module_init(ip6_tunnel_init);
2382 module_exit(ip6_tunnel_cleanup);