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 struct net_device_stats *ip6_get_stats(struct net_device *dev)
  93 {
  94         struct pcpu_sw_netstats tmp, sum = { 0 };
  95         int i;
  96
  97         for_each_possible_cpu(i) {
  98                 unsigned int start;
  99                 const struct pcpu_sw_netstats *tstats =
 100                                                    per_cpu_ptr(dev->tstats, i);
 101
 102                 do {
 103                         start = u64_stats_fetch_begin_irq(&tstats->syncp);
 104                         tmp.rx_packets = tstats->rx_packets;
 105                         tmp.rx_bytes = tstats->rx_bytes;
 106                         tmp.tx_packets = tstats->tx_packets;
 107                         tmp.tx_bytes =  tstats->tx_bytes;
 108                 } while (u64_stats_fetch_retry_irq(&tstats->syncp, start));
 109
 110                 sum.rx_packets += tmp.rx_packets;
 111                 sum.rx_bytes   += tmp.rx_bytes;
 112                 sum.tx_packets += tmp.tx_packets;
 113                 sum.tx_bytes   += tmp.tx_bytes;
 114         }
 115         dev->stats.rx_packets = sum.rx_packets;
 116         dev->stats.rx_bytes   = sum.rx_bytes;
 117         dev->stats.tx_packets = sum.tx_packets;
 118         dev->stats.tx_bytes   = sum.tx_bytes;
 119         return &dev->stats;
 120 }
 121
 122 /**
 123  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
 124  *   @link: ifindex of underlying interface
 125  *   @remote: the address of the tunnel exit-point
 126  *   @local: the address of the tunnel entry-point
 127  *
 128  * Return:
 129  *   tunnel matching given end-points if found,
 130  *   else fallback tunnel if its device is up,
 131  *   else %NULL
 132  **/
 133
 134 #define for_each_ip6_tunnel_rcu(start) \
 135         for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
 136
 137 static struct ip6_tnl *
 138 ip6_tnl_lookup(struct net *net, int link,
 139                const struct in6_addr *remote, const struct in6_addr *local)
 140 {
 141         unsigned int hash = HASH(remote, local);
 142         struct ip6_tnl *t, *cand = NULL;
 143         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 144         struct in6_addr any;
 145
 146         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 147                 if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 148                     !ipv6_addr_equal(remote, &t->parms.raddr) ||
 149                     !(t->dev->flags & IFF_UP))
 150                         continue;
 151
 152                 if (link == t->parms.link)
 153                         return t;
 154                 else
 155                         cand = t;
 156         }
 157
 158         memset(&any, 0, sizeof(any));
 159         hash = HASH(&any, local);
 160         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 161                 if (!ipv6_addr_equal(local, &t->parms.laddr) ||
 162                     !ipv6_addr_any(&t->parms.raddr) ||
 163                     !(t->dev->flags & IFF_UP))
 164                         continue;
 165
 166                 if (link == t->parms.link)
 167                         return t;
 168                 else if (!cand)
 169                         cand = t;
 170         }
 171
 172         hash = HASH(remote, &any);
 173         for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) {
 174                 if (!ipv6_addr_equal(remote, &t->parms.raddr) ||
 175                     !ipv6_addr_any(&t->parms.laddr) ||
 176                     !(t->dev->flags & IFF_UP))
 177                         continue;
 178
 179                 if (link == t->parms.link)
 180                         return t;
 181                 else if (!cand)
 182                         cand = t;
 183         }
 184
 185         if (cand)
 186                 return cand;
 187
 188         t = rcu_dereference(ip6n->collect_md_tun);
 189         if (t && t->dev->flags & IFF_UP)
 190                 return t;
 191
 192         t = rcu_dereference(ip6n->tnls_wc[0]);
 193         if (t && (t->dev->flags & IFF_UP))
 194                 return t;
 195
 196         return NULL;
 197 }
 198
 199 /**
 200  * ip6_tnl_bucket - get head of list matching given tunnel parameters
 201  *   @p: parameters containing tunnel end-points
 202  *
 203  * Description:
 204  *   ip6_tnl_bucket() returns the head of the list matching the
 205  *   &struct in6_addr entries laddr and raddr in @p.
 206  *
 207  * Return: head of IPv6 tunnel list
 208  **/
 209
 210 static struct ip6_tnl __rcu **
 211 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p)
 212 {
 213         const struct in6_addr *remote = &p->raddr;
 214         const struct in6_addr *local = &p->laddr;
 215         unsigned int h = 0;
 216         int prio = 0;
 217
 218         if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
 219                 prio = 1;
 220                 h = HASH(remote, local);
 221         }
 222         return &ip6n->tnls[prio][h];
 223 }
 224
 225 /**
 226  * ip6_tnl_link - add tunnel to hash table
 227  *   @t: tunnel to be added
 228  **/
 229
 230 static void
 231 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 232 {
 233         struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms);
 234
 235         if (t->parms.collect_md)
 236                 rcu_assign_pointer(ip6n->collect_md_tun, t);
 237         rcu_assign_pointer(t->next , rtnl_dereference(*tp));
 238         rcu_assign_pointer(*tp, t);
 239 }
 240
 241 /**
 242  * ip6_tnl_unlink - remove tunnel from hash table
 243  *   @t: tunnel to be removed
 244  **/
 245
 246 static void
 247 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
 248 {
 249         struct ip6_tnl __rcu **tp;
 250         struct ip6_tnl *iter;
 251
 252         if (t->parms.collect_md)
 253                 rcu_assign_pointer(ip6n->collect_md_tun, NULL);
 254
 255         for (tp = ip6_tnl_bucket(ip6n, &t->parms);
 256              (iter = rtnl_dereference(*tp)) != NULL;
 257              tp = &iter->next) {
 258                 if (t == iter) {
 259                         rcu_assign_pointer(*tp, t->next);
 260                         break;
 261                 }
 262         }
 263 }
 264
 265 static void ip6_dev_free(struct net_device *dev)
 266 {
 267         struct ip6_tnl *t = netdev_priv(dev);
 268
 269         gro_cells_destroy(&t->gro_cells);
 270         dst_cache_destroy(&t->dst_cache);
 271         free_percpu(dev->tstats);
 272 }
 273
 274 static int ip6_tnl_create2(struct net_device *dev)
 275 {
 276         struct ip6_tnl *t = netdev_priv(dev);
 277         struct net *net = dev_net(dev);
 278         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 279         int err;
 280
 281         t = netdev_priv(dev);
 282
 283         dev->rtnl_link_ops = &ip6_link_ops;
 284         err = register_netdevice(dev);
 285         if (err < 0)
 286                 goto out;
 287
 288         strcpy(t->parms.name, dev->name);
 289
 290         dev_hold(dev);
 291         ip6_tnl_link(ip6n, t);
 292         return 0;
 293
 294 out:
 295         return err;
 296 }
 297
 298 /**
 299  * ip6_tnl_create - create a new tunnel
 300  *   @p: tunnel parameters
 301  *   @pt: pointer to new tunnel
 302  *
 303  * Description:
 304  *   Create tunnel matching given parameters.
 305  *
 306  * Return:
 307  *   created tunnel or error pointer
 308  **/
 309
 310 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
 311 {
 312         struct net_device *dev;
 313         struct ip6_tnl *t;
 314         char name[IFNAMSIZ];
 315         int err = -E2BIG;
 316
 317         if (p->name[0]) {
 318                 if (!dev_valid_name(p->name))
 319                         goto failed;
 320                 strlcpy(name, p->name, IFNAMSIZ);
 321         } else {
 322                 sprintf(name, "ip6tnl%%d");
 323         }
 324         err = -ENOMEM;
 325         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 326                            ip6_tnl_dev_setup);
 327         if (!dev)
 328                 goto failed;
 329
 330         dev_net_set(dev, net);
 331
 332         t = netdev_priv(dev);
 333         t->parms = *p;
 334         t->net = dev_net(dev);
 335         err = ip6_tnl_create2(dev);
 336         if (err < 0)
 337                 goto failed_free;
 338
 339         return t;
 340
 341 failed_free:
 342         free_netdev(dev);
 343 failed:
 344         return ERR_PTR(err);
 345 }
 346
 347 /**
 348  * ip6_tnl_locate - find or create tunnel matching given parameters
 349  *   @p: tunnel parameters
 350  *   @create: != 0 if allowed to create new tunnel if no match found
 351  *
 352  * Description:
 353  *   ip6_tnl_locate() first tries to locate an existing tunnel
 354  *   based on @parms. If this is unsuccessful, but @create is set a new
 355  *   tunnel device is created and registered for use.
 356  *
 357  * Return:
 358  *   matching tunnel or error pointer
 359  **/
 360
 361 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
 362                 struct __ip6_tnl_parm *p, int create)
 363 {
 364         const struct in6_addr *remote = &p->raddr;
 365         const struct in6_addr *local = &p->laddr;
 366         struct ip6_tnl __rcu **tp;
 367         struct ip6_tnl *t;
 368         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 369
 370         for (tp = ip6_tnl_bucket(ip6n, p);
 371              (t = rtnl_dereference(*tp)) != NULL;
 372              tp = &t->next) {
 373                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 374                     ipv6_addr_equal(remote, &t->parms.raddr) &&
 375                     p->link == t->parms.link) {
 376                         if (create)
 377                                 return ERR_PTR(-EEXIST);
 378
 379                         return t;
 380                 }
 381         }
 382         if (!create)
 383                 return ERR_PTR(-ENODEV);
 384         return ip6_tnl_create(net, p);
 385 }
 386
 387 /**
 388  * ip6_tnl_dev_uninit - tunnel device uninitializer
 389  *   @dev: the device to be destroyed
 390  *
 391  * Description:
 392  *   ip6_tnl_dev_uninit() removes tunnel from its list
 393  **/
 394
 395 static void
 396 ip6_tnl_dev_uninit(struct net_device *dev)
 397 {
 398         struct ip6_tnl *t = netdev_priv(dev);
 399         struct net *net = t->net;
 400         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 401
 402         if (dev == ip6n->fb_tnl_dev)
 403                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
 404         else
 405                 ip6_tnl_unlink(ip6n, t);
 406         dst_cache_reset(&t->dst_cache);
 407         dev_put(dev);
 408 }
 409
 410 /**
 411  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
 412  *   @skb: received socket buffer
 413  *
 414  * Return:
 415  *   0 if none was found,
 416  *   else index to encapsulation limit
 417  **/
 418
 419 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
 420 {
 421         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)raw;
 422         unsigned int nhoff = raw - skb->data;
 423         unsigned int off = nhoff + sizeof(*ipv6h);
 424         u8 next, nexthdr = ipv6h->nexthdr;
 425
 426         while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
 427                 struct ipv6_opt_hdr *hdr;
 428                 u16 optlen;
 429
 430                 if (!pskb_may_pull(skb, off + sizeof(*hdr)))
 431                         break;
 432
 433                 hdr = (struct ipv6_opt_hdr *)(skb->data + off);
 434                 if (nexthdr == NEXTHDR_FRAGMENT) {
 435                         struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
 436                         if (frag_hdr->frag_off)
 437                                 break;
 438                         optlen = 8;
 439                 } else if (nexthdr == NEXTHDR_AUTH) {
 440                         optlen = ipv6_authlen(hdr);
 441                 } else {
 442                         optlen = ipv6_optlen(hdr);
 443                 }
 444                 /* cache hdr->nexthdr, since pskb_may_pull() might
 445                  * invalidate hdr
 446                  */
 447                 next = hdr->nexthdr;
 448                 if (nexthdr == NEXTHDR_DEST) {
 449                         u16 i = 2;
 450
 451                         /* Remember : hdr is no longer valid at this point. */
 452                         if (!pskb_may_pull(skb, off + optlen))
 453                                 break;
 454
 455                         while (1) {
 456                                 struct ipv6_tlv_tnl_enc_lim *tel;
 457
 458                                 /* No more room for encapsulation limit */
 459                                 if (i + sizeof(*tel) > optlen)
 460                                         break;
 461
 462                                 tel = (struct ipv6_tlv_tnl_enc_lim *)(skb->data + off + i);
 463                                 /* return index of option if found and valid */
 464                                 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
 465                                     tel->length == 1)
 466                                         return i + off - nhoff;
 467                                 /* else jump to next option */
 468                                 if (tel->type)
 469                                         i += tel->length + 2;
 470                                 else
 471                                         i++;
 472                         }
 473                 }
 474                 nexthdr = next;
 475                 off += optlen;
 476         }
 477         return 0;
 478 }
 479 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
 480
 481 /**
 482  * ip6_tnl_err - tunnel error handler
 483  *
 484  * Description:
 485  *   ip6_tnl_err() should handle errors in the tunnel according
 486  *   to the specifications in RFC 2473.
 487  **/
 488
 489 static int
 490 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
 491             u8 *type, u8 *code, int *msg, __u32 *info, int offset)
 492 {
 493         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 494         struct net *net = dev_net(skb->dev);
 495         u8 rel_type = ICMPV6_DEST_UNREACH;
 496         u8 rel_code = ICMPV6_ADDR_UNREACH;
 497         __u32 rel_info = 0;
 498         struct ip6_tnl *t;
 499         int err = -ENOENT;
 500         int rel_msg = 0;
 501         u8 tproto;
 502         __u16 len;
 503
 504         /* If the packet doesn't contain the original IPv6 header we are
 505            in trouble since we might need the source address for further
 506            processing of the error. */
 507
 508         rcu_read_lock();
 509         t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->daddr, &ipv6h->saddr);
 510         if (!t)
 511                 goto out;
 512
 513         tproto = READ_ONCE(t->parms.proto);
 514         if (tproto != ipproto && tproto != 0)
 515                 goto out;
 516
 517         err = 0;
 518
 519         switch (*type) {
 520         case ICMPV6_DEST_UNREACH:
 521                 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
 522                                     t->parms.name);
 523                 rel_msg = 1;
 524                 break;
 525         case ICMPV6_TIME_EXCEED:
 526                 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
 527                         net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 528                                             t->parms.name);
 529                         rel_msg = 1;
 530                 }
 531                 break;
 532         case ICMPV6_PARAMPROB: {
 533                 struct ipv6_tlv_tnl_enc_lim *tel;
 534                 __u32 teli;
 535
 536                 teli = 0;
 537                 if ((*code) == ICMPV6_HDR_FIELD)
 538                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 539
 540                 if (teli && teli == *info - 2) {
 541                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 542                         if (tel->encap_limit == 0) {
 543                                 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 544                                                     t->parms.name);
 545                                 rel_msg = 1;
 546                         }
 547                 } else {
 548                         net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 549                                             t->parms.name);
 550                 }
 551                 break;
 552         }
 553         case ICMPV6_PKT_TOOBIG: {
 554                 __u32 mtu;
 555
 556                 ip6_update_pmtu(skb, net, htonl(*info), 0, 0,
 557                                 sock_net_uid(net, NULL));
 558                 mtu = *info - offset;
 559                 if (mtu < IPV6_MIN_MTU)
 560                         mtu = IPV6_MIN_MTU;
 561                 len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
 562                 if (len > mtu) {
 563                         rel_type = ICMPV6_PKT_TOOBIG;
 564                         rel_code = 0;
 565                         rel_info = mtu;
 566                         rel_msg = 1;
 567                 }
 568                 break;
 569         }
 570         case NDISC_REDIRECT:
 571                 ip6_redirect(skb, net, skb->dev->ifindex, 0,
 572                              sock_net_uid(net, NULL));
 573                 break;
 574         }
 575
 576         *type = rel_type;
 577         *code = rel_code;
 578         *info = rel_info;
 579         *msg = rel_msg;
 580
 581 out:
 582         rcu_read_unlock();
 583         return err;
 584 }
 585
 586 static int
 587 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 588            u8 type, u8 code, int offset, __be32 info)
 589 {
 590         __u32 rel_info = ntohl(info);
 591         const struct iphdr *eiph;
 592         struct sk_buff *skb2;
 593         int err, rel_msg = 0;
 594         u8 rel_type = type;
 595         u8 rel_code = code;
 596         struct rtable *rt;
 597         struct flowi4 fl4;
 598
 599         err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
 600                           &rel_msg, &rel_info, offset);
 601         if (err < 0)
 602                 return err;
 603
 604         if (rel_msg == 0)
 605                 return 0;
 606
 607         switch (rel_type) {
 608         case ICMPV6_DEST_UNREACH:
 609                 if (rel_code != ICMPV6_ADDR_UNREACH)
 610                         return 0;
 611                 rel_type = ICMP_DEST_UNREACH;
 612                 rel_code = ICMP_HOST_UNREACH;
 613                 break;
 614         case ICMPV6_PKT_TOOBIG:
 615                 if (rel_code != 0)
 616                         return 0;
 617                 rel_type = ICMP_DEST_UNREACH;
 618                 rel_code = ICMP_FRAG_NEEDED;
 619                 break;
 620         default:
 621                 return 0;
 622         }
 623
 624         if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
 625                 return 0;
 626
 627         skb2 = skb_clone(skb, GFP_ATOMIC);
 628         if (!skb2)
 629                 return 0;
 630
 631         skb_dst_drop(skb2);
 632
 633         skb_pull(skb2, offset);
 634         skb_reset_network_header(skb2);
 635         eiph = ip_hdr(skb2);
 636
 637         /* Try to guess incoming interface */
 638         rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, eiph->saddr,
 639                                    0, 0, 0, IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 640         if (IS_ERR(rt))
 641                 goto out;
 642
 643         skb2->dev = rt->dst.dev;
 644         ip_rt_put(rt);
 645
 646         /* route "incoming" packet */
 647         if (rt->rt_flags & RTCF_LOCAL) {
 648                 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 649                                            eiph->daddr, eiph->saddr, 0, 0,
 650                                            IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 651                 if (IS_ERR(rt) || rt->dst.dev->type != ARPHRD_TUNNEL6) {
 652                         if (!IS_ERR(rt))
 653                                 ip_rt_put(rt);
 654                         goto out;
 655                 }
 656                 skb_dst_set(skb2, &rt->dst);
 657         } else {
 658                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
 659                                    skb2->dev) ||
 660                     skb_dst(skb2)->dev->type != ARPHRD_TUNNEL6)
 661                         goto out;
 662         }
 663
 664         /* change mtu on this route */
 665         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
 666                 if (rel_info > dst_mtu(skb_dst(skb2)))
 667                         goto out;
 668
 669                 skb_dst_update_pmtu_no_confirm(skb2, rel_info);
 670         }
 671
 672         icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
 673
 674 out:
 675         kfree_skb(skb2);
 676         return 0;
 677 }
 678
 679 static int
 680 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 681            u8 type, u8 code, int offset, __be32 info)
 682 {
 683         __u32 rel_info = ntohl(info);
 684         int err, rel_msg = 0;
 685         u8 rel_type = type;
 686         u8 rel_code = code;
 687
 688         err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
 689                           &rel_msg, &rel_info, offset);
 690         if (err < 0)
 691                 return err;
 692
 693         if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
 694                 struct rt6_info *rt;
 695                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 696
 697                 if (!skb2)
 698                         return 0;
 699
 700                 skb_dst_drop(skb2);
 701                 skb_pull(skb2, offset);
 702                 skb_reset_network_header(skb2);
 703
 704                 /* Try to guess incoming interface */
 705                 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
 706                                 NULL, 0, skb2, 0);
 707
 708                 if (rt && rt->dst.dev)
 709                         skb2->dev = rt->dst.dev;
 710
 711                 icmpv6_send(skb2, rel_type, rel_code, rel_info);
 712
 713                 ip6_rt_put(rt);
 714
 715                 kfree_skb(skb2);
 716         }
 717
 718         return 0;
 719 }
 720
 721 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 722                                        const struct ipv6hdr *ipv6h,
 723                                        struct sk_buff *skb)
 724 {
 725         __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
 726
 727         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 728                 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
 729
 730         return IP6_ECN_decapsulate(ipv6h, skb);
 731 }
 732
 733 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 734                                        const struct ipv6hdr *ipv6h,
 735                                        struct sk_buff *skb)
 736 {
 737         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 738                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
 739
 740         return IP6_ECN_decapsulate(ipv6h, skb);
 741 }
 742
 743 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
 744                              const struct in6_addr *laddr,
 745                              const struct in6_addr *raddr)
 746 {
 747         struct __ip6_tnl_parm *p = &t->parms;
 748         int ltype = ipv6_addr_type(laddr);
 749         int rtype = ipv6_addr_type(raddr);
 750         __u32 flags = 0;
 751
 752         if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
 753                 flags = IP6_TNL_F_CAP_PER_PACKET;
 754         } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 755                    rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 756                    !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
 757                    (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
 758                 if (ltype&IPV6_ADDR_UNICAST)
 759                         flags |= IP6_TNL_F_CAP_XMIT;
 760                 if (rtype&IPV6_ADDR_UNICAST)
 761                         flags |= IP6_TNL_F_CAP_RCV;
 762         }
 763         return flags;
 764 }
 765 EXPORT_SYMBOL(ip6_tnl_get_cap);
 766
 767 /* called with rcu_read_lock() */
 768 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
 769                                   const struct in6_addr *laddr,
 770                                   const struct in6_addr *raddr)
 771 {
 772         struct __ip6_tnl_parm *p = &t->parms;
 773         int ret = 0;
 774         struct net *net = t->net;
 775
 776         if ((p->flags & IP6_TNL_F_CAP_RCV) ||
 777             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
 778              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
 779                 struct net_device *ldev = NULL;
 780
 781                 if (p->link)
 782                         ldev = dev_get_by_index_rcu(net, p->link);
 783
 784                 if ((ipv6_addr_is_multicast(laddr) ||
 785                      likely(ipv6_chk_addr_and_flags(net, laddr, ldev, false,
 786                                                     0, IFA_F_TENTATIVE))) &&
 787                     ((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
 788                      likely(!ipv6_chk_addr_and_flags(net, raddr, ldev, true,
 789                                                      0, IFA_F_TENTATIVE))))
 790                         ret = 1;
 791         }
 792         return ret;
 793 }
 794 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
 795
 796 static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
 797                          const struct tnl_ptk_info *tpi,
 798                          struct metadata_dst *tun_dst,
 799                          int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 800                                                 const struct ipv6hdr *ipv6h,
 801                                                 struct sk_buff *skb),
 802                          bool log_ecn_err)
 803 {
 804         struct pcpu_sw_netstats *tstats;
 805         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 806         int err;
 807
 808         if ((!(tpi->flags & TUNNEL_CSUM) &&
 809              (tunnel->parms.i_flags & TUNNEL_CSUM)) ||
 810             ((tpi->flags & TUNNEL_CSUM) &&
 811              !(tunnel->parms.i_flags & TUNNEL_CSUM))) {
 812                 tunnel->dev->stats.rx_crc_errors++;
 813                 tunnel->dev->stats.rx_errors++;
 814                 goto drop;
 815         }
 816
 817         if (tunnel->parms.i_flags & TUNNEL_SEQ) {
 818                 if (!(tpi->flags & TUNNEL_SEQ) ||
 819                     (tunnel->i_seqno &&
 820                      (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
 821                         tunnel->dev->stats.rx_fifo_errors++;
 822                         tunnel->dev->stats.rx_errors++;
 823                         goto drop;
 824                 }
 825                 tunnel->i_seqno = ntohl(tpi->seq) + 1;
 826         }
 827
 828         skb->protocol = tpi->proto;
 829
 830         /* Warning: All skb pointers will be invalidated! */
 831         if (tunnel->dev->type == ARPHRD_ETHER) {
 832                 if (!pskb_may_pull(skb, ETH_HLEN)) {
 833                         tunnel->dev->stats.rx_length_errors++;
 834                         tunnel->dev->stats.rx_errors++;
 835                         goto drop;
 836                 }
 837
 838                 ipv6h = ipv6_hdr(skb);
 839                 skb->protocol = eth_type_trans(skb, tunnel->dev);
 840                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 841         } else {
 842                 skb->dev = tunnel->dev;
 843         }
 844
 845         skb_reset_network_header(skb);
 846         memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 847
 848         __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 849
 850         err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
 851         if (unlikely(err)) {
 852                 if (log_ecn_err)
 853                         net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
 854                                              &ipv6h->saddr,
 855                                              ipv6_get_dsfield(ipv6h));
 856                 if (err > 1) {
 857                         ++tunnel->dev->stats.rx_frame_errors;
 858                         ++tunnel->dev->stats.rx_errors;
 859                         goto drop;
 860                 }
 861         }
 862
 863         tstats = this_cpu_ptr(tunnel->dev->tstats);
 864         u64_stats_update_begin(&tstats->syncp);
 865         tstats->rx_packets++;
 866         tstats->rx_bytes += skb->len;
 867         u64_stats_update_end(&tstats->syncp);
 868
 869         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
 870
 871         if (tun_dst)
 872                 skb_dst_set(skb, (struct dst_entry *)tun_dst);
 873
 874         gro_cells_receive(&tunnel->gro_cells, skb);
 875         return 0;
 876
 877 drop:
 878         if (tun_dst)
 879                 dst_release((struct dst_entry *)tun_dst);
 880         kfree_skb(skb);
 881         return 0;
 882 }
 883
 884 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
 885                 const struct tnl_ptk_info *tpi,
 886                 struct metadata_dst *tun_dst,
 887                 bool log_ecn_err)
 888 {
 889         return __ip6_tnl_rcv(t, skb, tpi, tun_dst, ip6ip6_dscp_ecn_decapsulate,
 890                              log_ecn_err);
 891 }
 892 EXPORT_SYMBOL(ip6_tnl_rcv);
 893
 894 static const struct tnl_ptk_info tpi_v6 = {
 895         /* no tunnel info required for ipxip6. */
 896         .proto = htons(ETH_P_IPV6),
 897 };
 898
 899 static const struct tnl_ptk_info tpi_v4 = {
 900         /* no tunnel info required for ipxip6. */
 901         .proto = htons(ETH_P_IP),
 902 };
 903
 904 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
 905                       const struct tnl_ptk_info *tpi,
 906                       int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 907                                                   const struct ipv6hdr *ipv6h,
 908                                                   struct sk_buff *skb))
 909 {
 910         struct ip6_tnl *t;
 911         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 912         struct metadata_dst *tun_dst = NULL;
 913         int ret = -1;
 914
 915         rcu_read_lock();
 916         t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->saddr, &ipv6h->daddr);
 917
 918         if (t) {
 919                 u8 tproto = READ_ONCE(t->parms.proto);
 920
 921                 if (tproto != ipproto && tproto != 0)
 922                         goto drop;
 923                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 924                         goto drop;
 925                 ipv6h = ipv6_hdr(skb);
 926                 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
 927                         goto drop;
 928                 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
 929                         goto drop;
 930                 if (t->parms.collect_md) {
 931                         tun_dst = ipv6_tun_rx_dst(skb, 0, 0, 0);
 932                         if (!tun_dst)
 933                                 goto drop;
 934                 }
 935                 ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
 936                                     log_ecn_error);
 937         }
 938
 939         rcu_read_unlock();
 940
 941         return ret;
 942
 943 drop:
 944         rcu_read_unlock();
 945         kfree_skb(skb);
 946         return 0;
 947 }
 948
 949 static int ip4ip6_rcv(struct sk_buff *skb)
 950 {
 951         return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
 952                           ip4ip6_dscp_ecn_decapsulate);
 953 }
 954
 955 static int ip6ip6_rcv(struct sk_buff *skb)
 956 {
 957         return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
 958                           ip6ip6_dscp_ecn_decapsulate);
 959 }
 960
 961 struct ipv6_tel_txoption {
 962         struct ipv6_txoptions ops;
 963         __u8 dst_opt[8];
 964 };
 965
 966 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 967 {
 968         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 969
 970         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 971         opt->dst_opt[3] = 1;
 972         opt->dst_opt[4] = encap_limit;
 973         opt->dst_opt[5] = IPV6_TLV_PADN;
 974         opt->dst_opt[6] = 1;
 975
 976         opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 977         opt->ops.opt_nflen = 8;
 978 }
 979
 980 /**
 981  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 982  *   @t: the outgoing tunnel device
 983  *   @hdr: IPv6 header from the incoming packet
 984  *
 985  * Description:
 986  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 987  *   doesn't match source of incoming packet.
 988  *
 989  * Return:
 990  *   1 if conflict,
 991  *   0 else
 992  **/
 993
 994 static inline bool
 995 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
 996 {
 997         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 998 }
 999
1000 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
1001                      const struct in6_addr *laddr,
1002                      const struct in6_addr *raddr)
1003 {
1004         struct __ip6_tnl_parm *p = &t->parms;
1005         int ret = 0;
1006         struct net *net = t->net;
1007
1008         if (t->parms.collect_md)
1009                 return 1;
1010
1011         if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
1012             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
1013              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
1014                 struct net_device *ldev = NULL;
1015
1016                 rcu_read_lock();
1017                 if (p->link)
1018                         ldev = dev_get_by_index_rcu(net, p->link);
1019
1020                 if (unlikely(!ipv6_chk_addr_and_flags(net, laddr, ldev, false,
1021                                                       0, IFA_F_TENTATIVE)))
1022                         pr_warn("%s xmit: Local address not yet configured!\n",
1023                                 p->name);
1024                 else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
1025                          !ipv6_addr_is_multicast(raddr) &&
1026                          unlikely(ipv6_chk_addr_and_flags(net, raddr, ldev,
1027                                                           true, 0, IFA_F_TENTATIVE)))
1028                         pr_warn("%s xmit: Routing loop! Remote address found on this node!\n",
1029                                 p->name);
1030                 else
1031                         ret = 1;
1032                 rcu_read_unlock();
1033         }
1034         return ret;
1035 }
1036 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1037
1038 /**
1039  * ip6_tnl_xmit - encapsulate packet and send
1040  *   @skb: the outgoing socket buffer
1041  *   @dev: the outgoing tunnel device
1042  *   @dsfield: dscp code for outer header
1043  *   @fl6: flow of tunneled packet
1044  *   @encap_limit: encapsulation limit
1045  *   @pmtu: Path MTU is stored if packet is too big
1046  *   @proto: next header value
1047  *
1048  * Description:
1049  *   Build new header and do some sanity checks on the packet before sending
1050  *   it.
1051  *
1052  * Return:
1053  *   0 on success
1054  *   -1 fail
1055  *   %-EMSGSIZE message too big. return mtu in this case.
1056  **/
1057
1058 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1059                  struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1060                  __u8 proto)
1061 {
1062         struct ip6_tnl *t = netdev_priv(dev);
1063         struct net *net = t->net;
1064         struct net_device_stats *stats = &t->dev->stats;
1065         struct ipv6hdr *ipv6h;
1066         struct ipv6_tel_txoption opt;
1067         struct dst_entry *dst = NULL, *ndst = NULL;
1068         struct net_device *tdev;
1069         int mtu;
1070         unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1071         unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1072         unsigned int max_headroom = psh_hlen;
1073         bool use_cache = false;
1074         u8 hop_limit;
1075         int err = -1;
1076
1077         if (t->parms.collect_md) {
1078                 hop_limit = skb_tunnel_info(skb)->key.ttl;
1079                 goto route_lookup;
1080         } else {
1081                 hop_limit = t->parms.hop_limit;
1082         }
1083
1084         /* NBMA tunnel */
1085         if (ipv6_addr_any(&t->parms.raddr)) {
1086                 if (skb->protocol == htons(ETH_P_IPV6)) {
1087                         struct in6_addr *addr6;
1088                         struct neighbour *neigh;
1089                         int addr_type;
1090
1091                         if (!skb_dst(skb))
1092                                 goto tx_err_link_failure;
1093
1094                         neigh = dst_neigh_lookup(skb_dst(skb),
1095                                                  &ipv6_hdr(skb)->daddr);
1096                         if (!neigh)
1097                                 goto tx_err_link_failure;
1098
1099                         addr6 = (struct in6_addr *)&neigh->primary_key;
1100                         addr_type = ipv6_addr_type(addr6);
1101
1102                         if (addr_type == IPV6_ADDR_ANY)
1103                                 addr6 = &ipv6_hdr(skb)->daddr;
1104
1105                         memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1106                         neigh_release(neigh);
1107                 }
1108         } else if (t->parms.proto != 0 && !(t->parms.flags &
1109                                             (IP6_TNL_F_USE_ORIG_TCLASS |
1110                                              IP6_TNL_F_USE_ORIG_FWMARK))) {
1111                 /* enable the cache only if neither the outer protocol nor the
1112                  * routing decision depends on the current inner header value
1113                  */
1114                 use_cache = true;
1115         }
1116
1117         if (use_cache)
1118                 dst = dst_cache_get(&t->dst_cache);
1119
1120         if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1121                 goto tx_err_link_failure;
1122
1123         if (!dst) {
1124 route_lookup:
1125                 /* add dsfield to flowlabel for route lookup */
1126                 fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1127
1128                 dst = ip6_route_output(net, NULL, fl6);
1129
1130                 if (dst->error)
1131                         goto tx_err_link_failure;
1132                 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1133                 if (IS_ERR(dst)) {
1134                         err = PTR_ERR(dst);
1135                         dst = NULL;
1136                         goto tx_err_link_failure;
1137                 }
1138                 if (t->parms.collect_md && ipv6_addr_any(&fl6->saddr) &&
1139                     ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1140                                        &fl6->daddr, 0, &fl6->saddr))
1141                         goto tx_err_link_failure;
1142                 ndst = dst;
1143         }
1144
1145         tdev = dst->dev;
1146
1147         if (tdev == dev) {
1148                 stats->collisions++;
1149                 net_warn_ratelimited("%s: Local routing loop detected!\n",
1150                                      t->parms.name);
1151                 goto tx_err_dst_release;
1152         }
1153         mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
1154         if (encap_limit >= 0) {
1155                 max_headroom += 8;
1156                 mtu -= 8;
1157         }
1158         mtu = max(mtu, skb->protocol == htons(ETH_P_IPV6) ?
1159                        IPV6_MIN_MTU : IPV4_MIN_MTU);
1160
1161         skb_dst_update_pmtu_no_confirm(skb, mtu);
1162         if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
1163                 *pmtu = mtu;
1164                 err = -EMSGSIZE;
1165                 goto tx_err_dst_release;
1166         }
1167
1168         if (t->err_count > 0) {
1169                 if (time_before(jiffies,
1170                                 t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1171                         t->err_count--;
1172
1173                         dst_link_failure(skb);
1174                 } else {
1175                         t->err_count = 0;
1176                 }
1177         }
1178
1179         skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1180
1181         /*
1182          * Okay, now see if we can stuff it in the buffer as-is.
1183          */
1184         max_headroom += LL_RESERVED_SPACE(tdev);
1185
1186         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1187             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1188                 struct sk_buff *new_skb;
1189
1190                 new_skb = skb_realloc_headroom(skb, max_headroom);
1191                 if (!new_skb)
1192                         goto tx_err_dst_release;
1193
1194                 if (skb->sk)
1195                         skb_set_owner_w(new_skb, skb->sk);
1196                 consume_skb(skb);
1197                 skb = new_skb;
1198         }
1199
1200         if (t->parms.collect_md) {
1201                 if (t->encap.type != TUNNEL_ENCAP_NONE)
1202                         goto tx_err_dst_release;
1203         } else {
1204                 if (use_cache && ndst)
1205                         dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1206         }
1207         skb_dst_set(skb, dst);
1208
1209         if (hop_limit == 0) {
1210                 if (skb->protocol == htons(ETH_P_IP))
1211                         hop_limit = ip_hdr(skb)->ttl;
1212                 else if (skb->protocol == htons(ETH_P_IPV6))
1213                         hop_limit = ipv6_hdr(skb)->hop_limit;
1214                 else
1215                         hop_limit = ip6_dst_hoplimit(dst);
1216         }
1217
1218         /* Calculate max headroom for all the headers and adjust
1219          * needed_headroom if necessary.
1220          */
1221         max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1222                         + dst->header_len + t->hlen;
1223         if (max_headroom > dev->needed_headroom)
1224                 dev->needed_headroom = max_headroom;
1225
1226         err = ip6_tnl_encap(skb, t, &proto, fl6);
1227         if (err)
1228                 return err;
1229
1230         if (encap_limit >= 0) {
1231                 init_tel_txopt(&opt, encap_limit);
1232                 ipv6_push_frag_opts(skb, &opt.ops, &proto);
1233         }
1234
1235         skb_push(skb, sizeof(struct ipv6hdr));
1236         skb_reset_network_header(skb);
1237         ipv6h = ipv6_hdr(skb);
1238         ip6_flow_hdr(ipv6h, dsfield,
1239                      ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1240         ipv6h->hop_limit = hop_limit;
1241         ipv6h->nexthdr = proto;
1242         ipv6h->saddr = fl6->saddr;
1243         ipv6h->daddr = fl6->daddr;
1244         ip6tunnel_xmit(NULL, skb, dev);
1245         return 0;
1246 tx_err_link_failure:
1247         stats->tx_carrier_errors++;
1248         dst_link_failure(skb);
1249 tx_err_dst_release:
1250         dst_release(dst);
1251         return err;
1252 }
1253 EXPORT_SYMBOL(ip6_tnl_xmit);
1254
1255 static inline int
1256 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1257 {
1258         struct ip6_tnl *t = netdev_priv(dev);
1259         const struct iphdr  *iph;
1260         int encap_limit = -1;
1261         struct flowi6 fl6;
1262         __u8 dsfield;
1263         __u32 mtu;
1264         u8 tproto;
1265         int err;
1266
1267         iph = ip_hdr(skb);
1268         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
1269
1270         tproto = READ_ONCE(t->parms.proto);
1271         if (tproto != IPPROTO_IPIP && tproto != 0)
1272                 return -1;
1273
1274         if (t->parms.collect_md) {
1275                 struct ip_tunnel_info *tun_info;
1276                 const struct ip_tunnel_key *key;
1277
1278                 tun_info = skb_tunnel_info(skb);
1279                 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1280                              ip_tunnel_info_af(tun_info) != AF_INET6))
1281                         return -1;
1282                 key = &tun_info->key;
1283                 memset(&fl6, 0, sizeof(fl6));
1284                 fl6.flowi6_proto = IPPROTO_IPIP;
1285                 fl6.saddr = key->u.ipv6.src;
1286                 fl6.daddr = key->u.ipv6.dst;
1287                 fl6.flowlabel = key->label;
1288                 dsfield =  key->tos;
1289         } else {
1290                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1291                         encap_limit = t->parms.encap_limit;
1292
1293                 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1294                 fl6.flowi6_proto = IPPROTO_IPIP;
1295
1296                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1297                         dsfield = ipv4_get_dsfield(iph);
1298                 else
1299                         dsfield = ip6_tclass(t->parms.flowinfo);
1300                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1301                         fl6.flowi6_mark = skb->mark;
1302                 else
1303                         fl6.flowi6_mark = t->parms.fwmark;
1304         }
1305
1306         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1307         dsfield = INET_ECN_encapsulate(dsfield, ipv4_get_dsfield(iph));
1308
1309         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1310                 return -1;
1311
1312         skb_set_inner_ipproto(skb, IPPROTO_IPIP);
1313
1314         err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1315                            IPPROTO_IPIP);
1316         if (err != 0) {
1317                 /* XXX: send ICMP error even if DF is not set. */
1318                 if (err == -EMSGSIZE)
1319                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1320                                   htonl(mtu));
1321                 return -1;
1322         }
1323
1324         return 0;
1325 }
1326
1327 static inline int
1328 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1329 {
1330         struct ip6_tnl *t = netdev_priv(dev);
1331         struct ipv6hdr *ipv6h;
1332         int encap_limit = -1;
1333         __u16 offset;
1334         struct flowi6 fl6;
1335         __u8 dsfield;
1336         __u32 mtu;
1337         u8 tproto;
1338         int err;
1339
1340         ipv6h = ipv6_hdr(skb);
1341         tproto = READ_ONCE(t->parms.proto);
1342         if ((tproto != IPPROTO_IPV6 && tproto != 0) ||
1343             ip6_tnl_addr_conflict(t, ipv6h))
1344                 return -1;
1345
1346         if (t->parms.collect_md) {
1347                 struct ip_tunnel_info *tun_info;
1348                 const struct ip_tunnel_key *key;
1349
1350                 tun_info = skb_tunnel_info(skb);
1351                 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1352                              ip_tunnel_info_af(tun_info) != AF_INET6))
1353                         return -1;
1354                 key = &tun_info->key;
1355                 memset(&fl6, 0, sizeof(fl6));
1356                 fl6.flowi6_proto = IPPROTO_IPV6;
1357                 fl6.saddr = key->u.ipv6.src;
1358                 fl6.daddr = key->u.ipv6.dst;
1359                 fl6.flowlabel = key->label;
1360                 dsfield = key->tos;
1361         } else {
1362                 offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb));
1363                 /* ip6_tnl_parse_tlv_enc_lim() might have reallocated skb->head */
1364                 ipv6h = ipv6_hdr(skb);
1365                 if (offset > 0) {
1366                         struct ipv6_tlv_tnl_enc_lim *tel;
1367
1368                         tel = (void *)&skb_network_header(skb)[offset];
1369                         if (tel->encap_limit == 0) {
1370                                 icmpv6_send(skb, ICMPV6_PARAMPROB,
1371                                             ICMPV6_HDR_FIELD, offset + 2);
1372                                 return -1;
1373                         }
1374                         encap_limit = tel->encap_limit - 1;
1375                 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) {
1376                         encap_limit = t->parms.encap_limit;
1377                 }
1378
1379                 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1380                 fl6.flowi6_proto = IPPROTO_IPV6;
1381
1382                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1383                         dsfield = ipv6_get_dsfield(ipv6h);
1384                 else
1385                         dsfield = ip6_tclass(t->parms.flowinfo);
1386                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1387                         fl6.flowlabel |= ip6_flowlabel(ipv6h);
1388                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1389                         fl6.flowi6_mark = skb->mark;
1390                 else
1391                         fl6.flowi6_mark = t->parms.fwmark;
1392         }
1393
1394         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1395         dsfield = INET_ECN_encapsulate(dsfield, ipv6_get_dsfield(ipv6h));
1396
1397         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1398                 return -1;
1399
1400         skb_set_inner_ipproto(skb, IPPROTO_IPV6);
1401
1402         err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1403                            IPPROTO_IPV6);
1404         if (err != 0) {
1405                 if (err == -EMSGSIZE)
1406                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1407                 return -1;
1408         }
1409
1410         return 0;
1411 }
1412
1413 static netdev_tx_t
1414 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1415 {
1416         struct ip6_tnl *t = netdev_priv(dev);
1417         struct net_device_stats *stats = &t->dev->stats;
1418         int ret;
1419
1420         if (!pskb_inet_may_pull(skb))
1421                 goto tx_err;
1422
1423         switch (skb->protocol) {
1424         case htons(ETH_P_IP):
1425                 ret = ip4ip6_tnl_xmit(skb, dev);
1426                 break;
1427         case htons(ETH_P_IPV6):
1428                 ret = ip6ip6_tnl_xmit(skb, dev);
1429                 break;
1430         default:
1431                 goto tx_err;
1432         }
1433
1434         if (ret < 0)
1435                 goto tx_err;
1436
1437         return NETDEV_TX_OK;
1438
1439 tx_err:
1440         stats->tx_errors++;
1441         stats->tx_dropped++;
1442         kfree_skb(skb);
1443         return NETDEV_TX_OK;
1444 }
1445
1446 static void ip6_tnl_link_config(struct ip6_tnl *t)
1447 {
1448         struct net_device *dev = t->dev;
1449         struct net_device *tdev = NULL;
1450         struct __ip6_tnl_parm *p = &t->parms;
1451         struct flowi6 *fl6 = &t->fl.u.ip6;
1452         unsigned int mtu;
1453         int t_hlen;
1454
1455         memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1456         memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1457
1458         /* Set up flowi template */
1459         fl6->saddr = p->laddr;
1460         fl6->daddr = p->raddr;
1461         fl6->flowi6_oif = p->link;
1462         fl6->flowlabel = 0;
1463
1464         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1465                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1466         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1467                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1468
1469         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1470         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1471
1472         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1473                 dev->flags |= IFF_POINTOPOINT;
1474         else
1475                 dev->flags &= ~IFF_POINTOPOINT;
1476
1477         t->tun_hlen = 0;
1478         t->hlen = t->encap_hlen + t->tun_hlen;
1479         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1480
1481         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1482                 int strict = (ipv6_addr_type(&p->raddr) &
1483                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1484
1485                 struct rt6_info *rt = rt6_lookup(t->net,
1486                                                  &p->raddr, &p->laddr,
1487                                                  p->link, NULL, strict);
1488                 if (rt) {
1489                         tdev = rt->dst.dev;
1490                         ip6_rt_put(rt);
1491                 }
1492
1493                 if (!tdev && p->link)
1494                         tdev = __dev_get_by_index(t->net, p->link);
1495
1496                 if (tdev) {
1497                         dev->hard_header_len = tdev->hard_header_len + t_hlen;
1498                         mtu = min_t(unsigned int, tdev->mtu, IP6_MAX_MTU);
1499
1500                         dev->mtu = mtu - t_hlen;
1501                         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1502                                 dev->mtu -= 8;
1503
1504                         if (dev->mtu < IPV6_MIN_MTU)
1505                                 dev->mtu = IPV6_MIN_MTU;
1506                 }
1507         }
1508 }
1509
1510 /**
1511  * ip6_tnl_change - update the tunnel parameters
1512  *   @t: tunnel to be changed
1513  *   @p: tunnel configuration parameters
1514  *
1515  * Description:
1516  *   ip6_tnl_change() updates the tunnel parameters
1517  **/
1518
1519 static int
1520 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1521 {
1522         t->parms.laddr = p->laddr;
1523         t->parms.raddr = p->raddr;
1524         t->parms.flags = p->flags;
1525         t->parms.hop_limit = p->hop_limit;
1526         t->parms.encap_limit = p->encap_limit;
1527         t->parms.flowinfo = p->flowinfo;
1528         t->parms.link = p->link;
1529         t->parms.proto = p->proto;
1530         t->parms.fwmark = p->fwmark;
1531         dst_cache_reset(&t->dst_cache);
1532         ip6_tnl_link_config(t);
1533         return 0;
1534 }
1535
1536 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1537 {
1538         struct net *net = t->net;
1539         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1540         int err;
1541
1542         ip6_tnl_unlink(ip6n, t);
1543         synchronize_net();
1544         err = ip6_tnl_change(t, p);
1545         ip6_tnl_link(ip6n, t);
1546         netdev_state_change(t->dev);
1547         return err;
1548 }
1549
1550 static int ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1551 {
1552         /* for default tnl0 device allow to change only the proto */
1553         t->parms.proto = p->proto;
1554         netdev_state_change(t->dev);
1555         return 0;
1556 }
1557
1558 static void
1559 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1560 {
1561         p->laddr = u->laddr;
1562         p->raddr = u->raddr;
1563         p->flags = u->flags;
1564         p->hop_limit = u->hop_limit;
1565         p->encap_limit = u->encap_limit;
1566         p->flowinfo = u->flowinfo;
1567         p->link = u->link;
1568         p->proto = u->proto;
1569         memcpy(p->name, u->name, sizeof(u->name));
1570 }
1571
1572 static void
1573 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1574 {
1575         u->laddr = p->laddr;
1576         u->raddr = p->raddr;
1577         u->flags = p->flags;
1578         u->hop_limit = p->hop_limit;
1579         u->encap_limit = p->encap_limit;
1580         u->flowinfo = p->flowinfo;
1581         u->link = p->link;
1582         u->proto = p->proto;
1583         memcpy(u->name, p->name, sizeof(u->name));
1584 }
1585
1586 /**
1587  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1588  *   @dev: virtual device associated with tunnel
1589  *   @ifr: parameters passed from userspace
1590  *   @cmd: command to be performed
1591  *
1592  * Description:
1593  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1594  *   from userspace.
1595  *
1596  *   The possible commands are the following:
1597  *     %SIOCGETTUNNEL: get tunnel parameters for device
1598  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1599  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1600  *     %SIOCDELTUNNEL: delete tunnel
1601  *
1602  *   The fallback device "ip6tnl0", created during module
1603  *   initialization, can be used for creating other tunnel devices.
1604  *
1605  * Return:
1606  *   0 on success,
1607  *   %-EFAULT if unable to copy data to or from userspace,
1608  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1609  *   %-EINVAL if passed tunnel parameters are invalid,
1610  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1611  *   %-ENODEV if attempting to change or delete a nonexisting device
1612  **/
1613
1614 static int
1615 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1616 {
1617         int err = 0;
1618         struct ip6_tnl_parm p;
1619         struct __ip6_tnl_parm p1;
1620         struct ip6_tnl *t = netdev_priv(dev);
1621         struct net *net = t->net;
1622         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1623
1624         memset(&p1, 0, sizeof(p1));
1625
1626         switch (cmd) {
1627         case SIOCGETTUNNEL:
1628                 if (dev == ip6n->fb_tnl_dev) {
1629                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1630                                 err = -EFAULT;
1631                                 break;
1632                         }
1633                         ip6_tnl_parm_from_user(&p1, &p);
1634                         t = ip6_tnl_locate(net, &p1, 0);
1635                         if (IS_ERR(t))
1636                                 t = netdev_priv(dev);
1637                 } else {
1638                         memset(&p, 0, sizeof(p));
1639                 }
1640                 ip6_tnl_parm_to_user(&p, &t->parms);
1641                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) {
1642                         err = -EFAULT;
1643                 }
1644                 break;
1645         case SIOCADDTUNNEL:
1646         case SIOCCHGTUNNEL:
1647                 err = -EPERM;
1648                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1649                         break;
1650                 err = -EFAULT;
1651                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1652                         break;
1653                 err = -EINVAL;
1654                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1655                     p.proto != 0)
1656                         break;
1657                 ip6_tnl_parm_from_user(&p1, &p);
1658                 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1659                 if (cmd == SIOCCHGTUNNEL) {
1660                         if (!IS_ERR(t)) {
1661                                 if (t->dev != dev) {
1662                                         err = -EEXIST;
1663                                         break;
1664                                 }
1665                         } else
1666                                 t = netdev_priv(dev);
1667                         if (dev == ip6n->fb_tnl_dev)
1668                                 err = ip6_tnl0_update(t, &p1);
1669                         else
1670                                 err = ip6_tnl_update(t, &p1);
1671                 }
1672                 if (!IS_ERR(t)) {
1673                         err = 0;
1674                         ip6_tnl_parm_to_user(&p, &t->parms);
1675                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
1676                                 err = -EFAULT;
1677
1678                 } else {
1679                         err = PTR_ERR(t);
1680                 }
1681                 break;
1682         case SIOCDELTUNNEL:
1683                 err = -EPERM;
1684                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1685                         break;
1686
1687                 if (dev == ip6n->fb_tnl_dev) {
1688                         err = -EFAULT;
1689                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1690                                 break;
1691                         err = -ENOENT;
1692                         ip6_tnl_parm_from_user(&p1, &p);
1693                         t = ip6_tnl_locate(net, &p1, 0);
1694                         if (IS_ERR(t))
1695                                 break;
1696                         err = -EPERM;
1697                         if (t->dev == ip6n->fb_tnl_dev)
1698                                 break;
1699                         dev = t->dev;
1700                 }
1701                 err = 0;
1702                 unregister_netdevice(dev);
1703                 break;
1704         default:
1705                 err = -EINVAL;
1706         }
1707         return err;
1708 }
1709
1710 /**
1711  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1712  *   @dev: virtual device associated with tunnel
1713  *   @new_mtu: the new mtu
1714  *
1715  * Return:
1716  *   0 on success,
1717  *   %-EINVAL if mtu too small
1718  **/
1719
1720 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1721 {
1722         struct ip6_tnl *tnl = netdev_priv(dev);
1723
1724         if (tnl->parms.proto == IPPROTO_IPV6) {
1725                 if (new_mtu < IPV6_MIN_MTU)
1726                         return -EINVAL;
1727         } else {
1728                 if (new_mtu < ETH_MIN_MTU)
1729                         return -EINVAL;
1730         }
1731         if (tnl->parms.proto == IPPROTO_IPV6 || tnl->parms.proto == 0) {
1732                 if (new_mtu > IP6_MAX_MTU - dev->hard_header_len)
1733                         return -EINVAL;
1734         } else {
1735                 if (new_mtu > IP_MAX_MTU - dev->hard_header_len)
1736                         return -EINVAL;
1737         }
1738         dev->mtu = new_mtu;
1739         return 0;
1740 }
1741 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1742
1743 int ip6_tnl_get_iflink(const struct net_device *dev)
1744 {
1745         struct ip6_tnl *t = netdev_priv(dev);
1746
1747         return t->parms.link;
1748 }
1749 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1750
1751 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1752                           unsigned int num)
1753 {
1754         if (num >= MAX_IPTUN_ENCAP_OPS)
1755                 return -ERANGE;
1756
1757         return !cmpxchg((const struct ip6_tnl_encap_ops **)
1758                         &ip6tun_encaps[num],
1759                         NULL, ops) ? 0 : -1;
1760 }
1761 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1762
1763 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1764                           unsigned int num)
1765 {
1766         int ret;
1767
1768         if (num >= MAX_IPTUN_ENCAP_OPS)
1769                 return -ERANGE;
1770
1771         ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1772                        &ip6tun_encaps[num],
1773                        ops, NULL) == ops) ? 0 : -1;
1774
1775         synchronize_net();
1776
1777         return ret;
1778 }
1779 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1780
1781 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1782                         struct ip_tunnel_encap *ipencap)
1783 {
1784         int hlen;
1785
1786         memset(&t->encap, 0, sizeof(t->encap));
1787
1788         hlen = ip6_encap_hlen(ipencap);
1789         if (hlen < 0)
1790                 return hlen;
1791
1792         t->encap.type = ipencap->type;
1793         t->encap.sport = ipencap->sport;
1794         t->encap.dport = ipencap->dport;
1795         t->encap.flags = ipencap->flags;
1796
1797         t->encap_hlen = hlen;
1798         t->hlen = t->encap_hlen + t->tun_hlen;
1799
1800         return 0;
1801 }
1802 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1803
1804 static const struct net_device_ops ip6_tnl_netdev_ops = {
1805         .ndo_init       = ip6_tnl_dev_init,
1806         .ndo_uninit     = ip6_tnl_dev_uninit,
1807         .ndo_start_xmit = ip6_tnl_start_xmit,
1808         .ndo_do_ioctl   = ip6_tnl_ioctl,
1809         .ndo_change_mtu = ip6_tnl_change_mtu,
1810         .ndo_get_stats  = ip6_get_stats,
1811         .ndo_get_iflink = ip6_tnl_get_iflink,
1812 };
1813
1814 #define IPXIPX_FEATURES (NETIF_F_SG |           \
1815                          NETIF_F_FRAGLIST |     \
1816                          NETIF_F_HIGHDMA |      \
1817                          NETIF_F_GSO_SOFTWARE | \
1818                          NETIF_F_HW_CSUM)
1819
1820 /**
1821  * ip6_tnl_dev_setup - setup virtual tunnel device
1822  *   @dev: virtual device associated with tunnel
1823  *
1824  * Description:
1825  *   Initialize function pointers and device parameters
1826  **/
1827
1828 static void ip6_tnl_dev_setup(struct net_device *dev)
1829 {
1830         dev->netdev_ops = &ip6_tnl_netdev_ops;
1831         dev->needs_free_netdev = true;
1832         dev->priv_destructor = ip6_dev_free;
1833
1834         dev->type = ARPHRD_TUNNEL6;
1835         dev->flags |= IFF_NOARP;
1836         dev->addr_len = sizeof(struct in6_addr);
1837         dev->features |= NETIF_F_LLTX;
1838         netif_keep_dst(dev);
1839
1840         dev->features           |= IPXIPX_FEATURES;
1841         dev->hw_features        |= IPXIPX_FEATURES;
1842
1843         /* This perm addr will be used as interface identifier by IPv6 */
1844         dev->addr_assign_type = NET_ADDR_RANDOM;
1845         eth_random_addr(dev->perm_addr);
1846 }
1847
1848
1849 /**
1850  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1851  *   @dev: virtual device associated with tunnel
1852  **/
1853
1854 static inline int
1855 ip6_tnl_dev_init_gen(struct net_device *dev)
1856 {
1857         struct ip6_tnl *t = netdev_priv(dev);
1858         int ret;
1859         int t_hlen;
1860
1861         t->dev = dev;
1862         t->net = dev_net(dev);
1863         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1864         if (!dev->tstats)
1865                 return -ENOMEM;
1866
1867         ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1868         if (ret)
1869                 goto free_stats;
1870
1871         ret = gro_cells_init(&t->gro_cells, dev);
1872         if (ret)
1873                 goto destroy_dst;
1874
1875         t->tun_hlen = 0;
1876         t->hlen = t->encap_hlen + t->tun_hlen;
1877         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1878
1879         dev->type = ARPHRD_TUNNEL6;
1880         dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1881         dev->mtu = ETH_DATA_LEN - t_hlen;
1882         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1883                 dev->mtu -= 8;
1884         dev->min_mtu = ETH_MIN_MTU;
1885         dev->max_mtu = IP6_MAX_MTU - dev->hard_header_len;
1886
1887         return 0;
1888
1889 destroy_dst:
1890         dst_cache_destroy(&t->dst_cache);
1891 free_stats:
1892         free_percpu(dev->tstats);
1893         dev->tstats = NULL;
1894
1895         return ret;
1896 }
1897
1898 /**
1899  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1900  *   @dev: virtual device associated with tunnel
1901  **/
1902
1903 static int ip6_tnl_dev_init(struct net_device *dev)
1904 {
1905         struct ip6_tnl *t = netdev_priv(dev);
1906         int err = ip6_tnl_dev_init_gen(dev);
1907
1908         if (err)
1909                 return err;
1910         ip6_tnl_link_config(t);
1911         if (t->parms.collect_md)
1912                 netif_keep_dst(dev);
1913         return 0;
1914 }
1915
1916 /**
1917  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1918  *   @dev: fallback device
1919  *
1920  * Return: 0
1921  **/
1922
1923 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1924 {
1925         struct ip6_tnl *t = netdev_priv(dev);
1926         struct net *net = dev_net(dev);
1927         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1928
1929         t->parms.proto = IPPROTO_IPV6;
1930         dev_hold(dev);
1931
1932         rcu_assign_pointer(ip6n->tnls_wc[0], t);
1933         return 0;
1934 }
1935
1936 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[],
1937                             struct netlink_ext_ack *extack)
1938 {
1939         u8 proto;
1940
1941         if (!data || !data[IFLA_IPTUN_PROTO])
1942                 return 0;
1943
1944         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1945         if (proto != IPPROTO_IPV6 &&
1946             proto != IPPROTO_IPIP &&
1947             proto != 0)
1948                 return -EINVAL;
1949
1950         return 0;
1951 }
1952
1953 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1954                                   struct __ip6_tnl_parm *parms)
1955 {
1956         memset(parms, 0, sizeof(*parms));
1957
1958         if (!data)
1959                 return;
1960
1961         if (data[IFLA_IPTUN_LINK])
1962                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1963
1964         if (data[IFLA_IPTUN_LOCAL])
1965                 parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1966
1967         if (data[IFLA_IPTUN_REMOTE])
1968                 parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1969
1970         if (data[IFLA_IPTUN_TTL])
1971                 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1972
1973         if (data[IFLA_IPTUN_ENCAP_LIMIT])
1974                 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1975
1976         if (data[IFLA_IPTUN_FLOWINFO])
1977                 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1978
1979         if (data[IFLA_IPTUN_FLAGS])
1980                 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1981
1982         if (data[IFLA_IPTUN_PROTO])
1983                 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1984
1985         if (data[IFLA_IPTUN_COLLECT_METADATA])
1986                 parms->collect_md = true;
1987
1988         if (data[IFLA_IPTUN_FWMARK])
1989                 parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1990 }
1991
1992 static bool ip6_tnl_netlink_encap_parms(struct nlattr *data[],
1993                                         struct ip_tunnel_encap *ipencap)
1994 {
1995         bool ret = false;
1996
1997         memset(ipencap, 0, sizeof(*ipencap));
1998
1999         if (!data)
2000                 return ret;
2001
2002         if (data[IFLA_IPTUN_ENCAP_TYPE]) {
2003                 ret = true;
2004                 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
2005         }
2006
2007         if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
2008                 ret = true;
2009                 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
2010         }
2011
2012         if (data[IFLA_IPTUN_ENCAP_SPORT]) {
2013                 ret = true;
2014                 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
2015         }
2016
2017         if (data[IFLA_IPTUN_ENCAP_DPORT]) {
2018                 ret = true;
2019                 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
2020         }
2021
2022         return ret;
2023 }
2024
2025 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
2026                            struct nlattr *tb[], struct nlattr *data[],
2027                            struct netlink_ext_ack *extack)
2028 {
2029         struct net *net = dev_net(dev);
2030         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2031         struct ip_tunnel_encap ipencap;
2032         struct ip6_tnl *nt, *t;
2033         int err;
2034
2035         nt = netdev_priv(dev);
2036
2037         if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2038                 err = ip6_tnl_encap_setup(nt, &ipencap);
2039                 if (err < 0)
2040                         return err;
2041         }
2042
2043         ip6_tnl_netlink_parms(data, &nt->parms);
2044
2045         if (nt->parms.collect_md) {
2046                 if (rtnl_dereference(ip6n->collect_md_tun))
2047                         return -EEXIST;
2048         } else {
2049                 t = ip6_tnl_locate(net, &nt->parms, 0);
2050                 if (!IS_ERR(t))
2051                         return -EEXIST;
2052         }
2053
2054         err = ip6_tnl_create2(dev);
2055         if (!err && tb[IFLA_MTU])
2056                 ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
2057
2058         return err;
2059 }
2060
2061 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
2062                               struct nlattr *data[],
2063                               struct netlink_ext_ack *extack)
2064 {
2065         struct ip6_tnl *t = netdev_priv(dev);
2066         struct __ip6_tnl_parm p;
2067         struct net *net = t->net;
2068         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2069         struct ip_tunnel_encap ipencap;
2070
2071         if (dev == ip6n->fb_tnl_dev)
2072                 return -EINVAL;
2073
2074         if (ip6_tnl_netlink_encap_parms(data, &ipencap)) {
2075                 int err = ip6_tnl_encap_setup(t, &ipencap);
2076
2077                 if (err < 0)
2078                         return err;
2079         }
2080         ip6_tnl_netlink_parms(data, &p);
2081         if (p.collect_md)
2082                 return -EINVAL;
2083
2084         t = ip6_tnl_locate(net, &p, 0);
2085         if (!IS_ERR(t)) {
2086                 if (t->dev != dev)
2087                         return -EEXIST;
2088         } else
2089                 t = netdev_priv(dev);
2090
2091         return ip6_tnl_update(t, &p);
2092 }
2093
2094 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2095 {
2096         struct net *net = dev_net(dev);
2097         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2098
2099         if (dev != ip6n->fb_tnl_dev)
2100                 unregister_netdevice_queue(dev, head);
2101 }
2102
2103 static size_t ip6_tnl_get_size(const struct net_device *dev)
2104 {
2105         return
2106                 /* IFLA_IPTUN_LINK */
2107                 nla_total_size(4) +
2108                 /* IFLA_IPTUN_LOCAL */
2109                 nla_total_size(sizeof(struct in6_addr)) +
2110                 /* IFLA_IPTUN_REMOTE */
2111                 nla_total_size(sizeof(struct in6_addr)) +
2112                 /* IFLA_IPTUN_TTL */
2113                 nla_total_size(1) +
2114                 /* IFLA_IPTUN_ENCAP_LIMIT */
2115                 nla_total_size(1) +
2116                 /* IFLA_IPTUN_FLOWINFO */
2117                 nla_total_size(4) +
2118                 /* IFLA_IPTUN_FLAGS */
2119                 nla_total_size(4) +
2120                 /* IFLA_IPTUN_PROTO */
2121                 nla_total_size(1) +
2122                 /* IFLA_IPTUN_ENCAP_TYPE */
2123                 nla_total_size(2) +
2124                 /* IFLA_IPTUN_ENCAP_FLAGS */
2125                 nla_total_size(2) +
2126                 /* IFLA_IPTUN_ENCAP_SPORT */
2127                 nla_total_size(2) +
2128                 /* IFLA_IPTUN_ENCAP_DPORT */
2129                 nla_total_size(2) +
2130                 /* IFLA_IPTUN_COLLECT_METADATA */
2131                 nla_total_size(0) +
2132                 /* IFLA_IPTUN_FWMARK */
2133                 nla_total_size(4) +
2134                 0;
2135 }
2136
2137 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2138 {
2139         struct ip6_tnl *tunnel = netdev_priv(dev);
2140         struct __ip6_tnl_parm *parm = &tunnel->parms;
2141
2142         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2143             nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2144             nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2145             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2146             nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2147             nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2148             nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2149             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
2150             nla_put_u32(skb, IFLA_IPTUN_FWMARK, parm->fwmark))
2151                 goto nla_put_failure;
2152
2153         if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2154             nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2155             nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2156             nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2157                 goto nla_put_failure;
2158
2159         if (parm->collect_md)
2160                 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2161                         goto nla_put_failure;
2162
2163         return 0;
2164
2165 nla_put_failure:
2166         return -EMSGSIZE;
2167 }
2168
2169 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2170 {
2171         struct ip6_tnl *tunnel = netdev_priv(dev);
2172
2173         return tunnel->net;
2174 }
2175 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2176
2177 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2178         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
2179         [IFLA_IPTUN_LOCAL]              = { .len = sizeof(struct in6_addr) },
2180         [IFLA_IPTUN_REMOTE]             = { .len = sizeof(struct in6_addr) },
2181         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
2182         [IFLA_IPTUN_ENCAP_LIMIT]        = { .type = NLA_U8 },
2183         [IFLA_IPTUN_FLOWINFO]           = { .type = NLA_U32 },
2184         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U32 },
2185         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
2186         [IFLA_IPTUN_ENCAP_TYPE]         = { .type = NLA_U16 },
2187         [IFLA_IPTUN_ENCAP_FLAGS]        = { .type = NLA_U16 },
2188         [IFLA_IPTUN_ENCAP_SPORT]        = { .type = NLA_U16 },
2189         [IFLA_IPTUN_ENCAP_DPORT]        = { .type = NLA_U16 },
2190         [IFLA_IPTUN_COLLECT_METADATA]   = { .type = NLA_FLAG },
2191         [IFLA_IPTUN_FWMARK]             = { .type = NLA_U32 },
2192 };
2193
2194 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2195         .kind           = "ip6tnl",
2196         .maxtype        = IFLA_IPTUN_MAX,
2197         .policy         = ip6_tnl_policy,
2198         .priv_size      = sizeof(struct ip6_tnl),
2199         .setup          = ip6_tnl_dev_setup,
2200         .validate       = ip6_tnl_validate,
2201         .newlink        = ip6_tnl_newlink,
2202         .changelink     = ip6_tnl_changelink,
2203         .dellink        = ip6_tnl_dellink,
2204         .get_size       = ip6_tnl_get_size,
2205         .fill_info      = ip6_tnl_fill_info,
2206         .get_link_net   = ip6_tnl_get_link_net,
2207 };
2208
2209 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2210         .handler        = ip4ip6_rcv,
2211         .err_handler    = ip4ip6_err,
2212         .priority       =       1,
2213 };
2214
2215 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2216         .handler        = ip6ip6_rcv,
2217         .err_handler    = ip6ip6_err,
2218         .priority       =       1,
2219 };
2220
2221 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net, struct list_head *list)
2222 {
2223         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2224         struct net_device *dev, *aux;
2225         int h;
2226         struct ip6_tnl *t;
2227
2228         for_each_netdev_safe(net, dev, aux)
2229                 if (dev->rtnl_link_ops == &ip6_link_ops)
2230                         unregister_netdevice_queue(dev, list);
2231
2232         for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2233                 t = rtnl_dereference(ip6n->tnls_r_l[h]);
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
2245 static int __net_init ip6_tnl_init_net(struct net *net)
2246 {
2247         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2248         struct ip6_tnl *t = NULL;
2249         int err;
2250
2251         ip6n->tnls[0] = ip6n->tnls_wc;
2252         ip6n->tnls[1] = ip6n->tnls_r_l;
2253
2254         if (!net_has_fallback_tunnels(net))
2255                 return 0;
2256         err = -ENOMEM;
2257         ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2258                                         NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2259
2260         if (!ip6n->fb_tnl_dev)
2261                 goto err_alloc_dev;
2262         dev_net_set(ip6n->fb_tnl_dev, net);
2263         ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2264         /* FB netdevice is special: we have one, and only one per netns.
2265          * Allowing to move it to another netns is clearly unsafe.
2266          */
2267         ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2268
2269         err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2270         if (err < 0)
2271                 goto err_register;
2272
2273         err = register_netdev(ip6n->fb_tnl_dev);
2274         if (err < 0)
2275                 goto err_register;
2276
2277         t = netdev_priv(ip6n->fb_tnl_dev);
2278
2279         strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2280         return 0;
2281
2282 err_register:
2283         free_netdev(ip6n->fb_tnl_dev);
2284 err_alloc_dev:
2285         return err;
2286 }
2287
2288 static void __net_exit ip6_tnl_exit_batch_net(struct list_head *net_list)
2289 {
2290         struct net *net;
2291         LIST_HEAD(list);
2292
2293         rtnl_lock();
2294         list_for_each_entry(net, net_list, exit_list)
2295                 ip6_tnl_destroy_tunnels(net, &list);
2296         unregister_netdevice_many(&list);
2297         rtnl_unlock();
2298 }
2299
2300 static struct pernet_operations ip6_tnl_net_ops = {
2301         .init = ip6_tnl_init_net,
2302         .exit_batch = ip6_tnl_exit_batch_net,
2303         .id   = &ip6_tnl_net_id,
2304         .size = sizeof(struct ip6_tnl_net),
2305 };
2306
2307 /**
2308  * ip6_tunnel_init - register protocol and reserve needed resources
2309  *
2310  * Return: 0 on success
2311  **/
2312
2313 static int __init ip6_tunnel_init(void)
2314 {
2315         int  err;
2316
2317         if (!ipv6_mod_enabled())
2318                 return -EOPNOTSUPP;
2319
2320         err = register_pernet_device(&ip6_tnl_net_ops);
2321         if (err < 0)
2322                 goto out_pernet;
2323
2324         err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2325         if (err < 0) {
2326                 pr_err("%s: can't register ip4ip6\n", __func__);
2327                 goto out_ip4ip6;
2328         }
2329
2330         err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2331         if (err < 0) {
2332                 pr_err("%s: can't register ip6ip6\n", __func__);
2333                 goto out_ip6ip6;
2334         }
2335         err = rtnl_link_register(&ip6_link_ops);
2336         if (err < 0)
2337                 goto rtnl_link_failed;
2338
2339         return 0;
2340
2341 rtnl_link_failed:
2342         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2343 out_ip6ip6:
2344         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2345 out_ip4ip6:
2346         unregister_pernet_device(&ip6_tnl_net_ops);
2347 out_pernet:
2348         return err;
2349 }
2350
2351 /**
2352  * ip6_tunnel_cleanup - free resources and unregister protocol
2353  **/
2354
2355 static void __exit ip6_tunnel_cleanup(void)
2356 {
2357         rtnl_link_unregister(&ip6_link_ops);
2358         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2359                 pr_info("%s: can't deregister ip4ip6\n", __func__);
2360
2361         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2362                 pr_info("%s: can't deregister ip6ip6\n", __func__);
2363
2364         unregister_pernet_device(&ip6_tnl_net_ops);
2365 }
2366
2367 module_init(ip6_tunnel_init);
2368 module_exit(ip6_tunnel_cleanup);