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 }
 251
 252 static int ip6_tnl_create2(struct net_device *dev)
 253 {
 254         struct ip6_tnl *t = netdev_priv(dev);
 255         struct net *net = dev_net(dev);
 256         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 257         int err;
 258
 259         dev->rtnl_link_ops = &ip6_link_ops;
 260         err = register_netdevice(dev);
 261         if (err < 0)
 262                 goto out;
 263
 264         strcpy(t->parms.name, dev->name);
 265
 266         ip6_tnl_link(ip6n, t);
 267         return 0;
 268
 269 out:
 270         return err;
 271 }
 272
 273 /**
 274  * ip6_tnl_create - create a new tunnel
 275  *   @net: network namespace
 276  *   @p: tunnel parameters
 277  *
 278  * Description:
 279  *   Create tunnel matching given parameters.
 280  *
 281  * Return:
 282  *   created tunnel or error pointer
 283  **/
 284
 285 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p)
 286 {
 287         struct net_device *dev;
 288         struct ip6_tnl *t;
 289         char name[IFNAMSIZ];
 290         int err = -E2BIG;
 291
 292         if (p->name[0]) {
 293                 if (!dev_valid_name(p->name))
 294                         goto failed;
 295                 strscpy(name, p->name, IFNAMSIZ);
 296         } else {
 297                 sprintf(name, "ip6tnl%%d");
 298         }
 299         err = -ENOMEM;
 300         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 301                            ip6_tnl_dev_setup);
 302         if (!dev)
 303                 goto failed;
 304
 305         dev_net_set(dev, net);
 306
 307         t = netdev_priv(dev);
 308         t->parms = *p;
 309         t->net = dev_net(dev);
 310         err = ip6_tnl_create2(dev);
 311         if (err < 0)
 312                 goto failed_free;
 313
 314         return t;
 315
 316 failed_free:
 317         free_netdev(dev);
 318 failed:
 319         return ERR_PTR(err);
 320 }
 321
 322 /**
 323  * ip6_tnl_locate - find or create tunnel matching given parameters
 324  *   @net: network namespace
 325  *   @p: tunnel parameters
 326  *   @create: != 0 if allowed to create new tunnel if no match found
 327  *
 328  * Description:
 329  *   ip6_tnl_locate() first tries to locate an existing tunnel
 330  *   based on @parms. If this is unsuccessful, but @create is set a new
 331  *   tunnel device is created and registered for use.
 332  *
 333  * Return:
 334  *   matching tunnel or error pointer
 335  **/
 336
 337 static struct ip6_tnl *ip6_tnl_locate(struct net *net,
 338                 struct __ip6_tnl_parm *p, int create)
 339 {
 340         const struct in6_addr *remote = &p->raddr;
 341         const struct in6_addr *local = &p->laddr;
 342         struct ip6_tnl __rcu **tp;
 343         struct ip6_tnl *t;
 344         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 345
 346         for (tp = ip6_tnl_bucket(ip6n, p);
 347              (t = rtnl_dereference(*tp)) != NULL;
 348              tp = &t->next) {
 349                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 350                     ipv6_addr_equal(remote, &t->parms.raddr) &&
 351                     p->link == t->parms.link) {
 352                         if (create)
 353                                 return ERR_PTR(-EEXIST);
 354
 355                         return t;
 356                 }
 357         }
 358         if (!create)
 359                 return ERR_PTR(-ENODEV);
 360         return ip6_tnl_create(net, p);
 361 }
 362
 363 /**
 364  * ip6_tnl_dev_uninit - tunnel device uninitializer
 365  *   @dev: the device to be destroyed
 366  *
 367  * Description:
 368  *   ip6_tnl_dev_uninit() removes tunnel from its list
 369  **/
 370
 371 static void
 372 ip6_tnl_dev_uninit(struct net_device *dev)
 373 {
 374         struct ip6_tnl *t = netdev_priv(dev);
 375         struct net *net = t->net;
 376         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
 377
 378         if (dev == ip6n->fb_tnl_dev)
 379                 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL);
 380         else
 381                 ip6_tnl_unlink(ip6n, t);
 382         dst_cache_reset(&t->dst_cache);
 383         netdev_put(dev, &t->dev_tracker);
 384 }
 385
 386 /**
 387  * ip6_tnl_parse_tlv_enc_lim - handle encapsulation limit option
 388  *   @skb: received socket buffer
 389  *   @raw: the ICMPv6 error message data
 390  *
 391  * Return:
 392  *   0 if none was found,
 393  *   else index to encapsulation limit
 394  **/
 395
 396 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw)
 397 {
 398         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)raw;
 399         unsigned int nhoff = raw - skb->data;
 400         unsigned int off = nhoff + sizeof(*ipv6h);
 401         u8 nexthdr = ipv6h->nexthdr;
 402
 403         while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
 404                 struct ipv6_opt_hdr *hdr;
 405                 u16 optlen;
 406
 407                 if (!pskb_may_pull(skb, off + sizeof(*hdr)))
 408                         break;
 409
 410                 hdr = (struct ipv6_opt_hdr *)(skb->data + off);
 411                 if (nexthdr == NEXTHDR_FRAGMENT) {
 412                         optlen = 8;
 413                 } else if (nexthdr == NEXTHDR_AUTH) {
 414                         optlen = ipv6_authlen(hdr);
 415                 } else {
 416                         optlen = ipv6_optlen(hdr);
 417                 }
 418
 419                 if (!pskb_may_pull(skb, off + optlen))
 420                         break;
 421
 422                 hdr = (struct ipv6_opt_hdr *)(skb->data + off);
 423                 if (nexthdr == NEXTHDR_FRAGMENT) {
 424                         struct frag_hdr *frag_hdr = (struct frag_hdr *)hdr;
 425
 426                         if (frag_hdr->frag_off)
 427                                 break;
 428                 }
 429                 if (nexthdr == NEXTHDR_DEST) {
 430                         u16 i = 2;
 431
 432                         while (1) {
 433                                 struct ipv6_tlv_tnl_enc_lim *tel;
 434
 435                                 /* No more room for encapsulation limit */
 436                                 if (i + sizeof(*tel) > optlen)
 437                                         break;
 438
 439                                 tel = (struct ipv6_tlv_tnl_enc_lim *)(skb->data + off + i);
 440                                 /* return index of option if found and valid */
 441                                 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
 442                                     tel->length == 1)
 443                                         return i + off - nhoff;
 444                                 /* else jump to next option */
 445                                 if (tel->type)
 446                                         i += tel->length + 2;
 447                                 else
 448                                         i++;
 449                         }
 450                 }
 451                 nexthdr = hdr->nexthdr;
 452                 off += optlen;
 453         }
 454         return 0;
 455 }
 456 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim);
 457
 458 /* ip6_tnl_err() should handle errors in the tunnel according to the
 459  * specifications in RFC 2473.
 460  */
 461 static int
 462 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
 463             u8 *type, u8 *code, int *msg, __u32 *info, int offset)
 464 {
 465         const struct ipv6hdr *ipv6h = (const struct ipv6hdr *)skb->data;
 466         struct net *net = dev_net(skb->dev);
 467         u8 rel_type = ICMPV6_DEST_UNREACH;
 468         u8 rel_code = ICMPV6_ADDR_UNREACH;
 469         __u32 rel_info = 0;
 470         struct ip6_tnl *t;
 471         int err = -ENOENT;
 472         int rel_msg = 0;
 473         u8 tproto;
 474         __u16 len;
 475
 476         /* If the packet doesn't contain the original IPv6 header we are
 477            in trouble since we might need the source address for further
 478            processing of the error. */
 479
 480         rcu_read_lock();
 481         t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->daddr, &ipv6h->saddr);
 482         if (!t)
 483                 goto out;
 484
 485         tproto = READ_ONCE(t->parms.proto);
 486         if (tproto != ipproto && tproto != 0)
 487                 goto out;
 488
 489         err = 0;
 490
 491         switch (*type) {
 492         case ICMPV6_DEST_UNREACH:
 493                 net_dbg_ratelimited("%s: Path to destination invalid or inactive!\n",
 494                                     t->parms.name);
 495                 rel_msg = 1;
 496                 break;
 497         case ICMPV6_TIME_EXCEED:
 498                 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
 499                         net_dbg_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n",
 500                                             t->parms.name);
 501                         rel_msg = 1;
 502                 }
 503                 break;
 504         case ICMPV6_PARAMPROB: {
 505                 struct ipv6_tlv_tnl_enc_lim *tel;
 506                 __u32 teli;
 507
 508                 teli = 0;
 509                 if ((*code) == ICMPV6_HDR_FIELD)
 510                         teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data);
 511
 512                 if (teli && teli == *info - 2) {
 513                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 514                         if (tel->encap_limit == 0) {
 515                                 net_dbg_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n",
 516                                                     t->parms.name);
 517                                 rel_msg = 1;
 518                         }
 519                 } else {
 520                         net_dbg_ratelimited("%s: Recipient unable to parse tunneled packet!\n",
 521                                             t->parms.name);
 522                 }
 523                 break;
 524         }
 525         case ICMPV6_PKT_TOOBIG: {
 526                 __u32 mtu;
 527
 528                 ip6_update_pmtu(skb, net, htonl(*info), 0, 0,
 529                                 sock_net_uid(net, NULL));
 530                 mtu = *info - offset;
 531                 if (mtu < IPV6_MIN_MTU)
 532                         mtu = IPV6_MIN_MTU;
 533                 len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len);
 534                 if (len > mtu) {
 535                         rel_type = ICMPV6_PKT_TOOBIG;
 536                         rel_code = 0;
 537                         rel_info = mtu;
 538                         rel_msg = 1;
 539                 }
 540                 break;
 541         }
 542         case NDISC_REDIRECT:
 543                 ip6_redirect(skb, net, skb->dev->ifindex, 0,
 544                              sock_net_uid(net, NULL));
 545                 break;
 546         }
 547
 548         *type = rel_type;
 549         *code = rel_code;
 550         *info = rel_info;
 551         *msg = rel_msg;
 552
 553 out:
 554         rcu_read_unlock();
 555         return err;
 556 }
 557
 558 static int
 559 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 560            u8 type, u8 code, int offset, __be32 info)
 561 {
 562         __u32 rel_info = ntohl(info);
 563         const struct iphdr *eiph;
 564         struct sk_buff *skb2;
 565         int err, rel_msg = 0;
 566         u8 rel_type = type;
 567         u8 rel_code = code;
 568         struct rtable *rt;
 569         struct flowi4 fl4;
 570
 571         err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
 572                           &rel_msg, &rel_info, offset);
 573         if (err < 0)
 574                 return err;
 575
 576         if (rel_msg == 0)
 577                 return 0;
 578
 579         switch (rel_type) {
 580         case ICMPV6_DEST_UNREACH:
 581                 if (rel_code != ICMPV6_ADDR_UNREACH)
 582                         return 0;
 583                 rel_type = ICMP_DEST_UNREACH;
 584                 rel_code = ICMP_HOST_UNREACH;
 585                 break;
 586         case ICMPV6_PKT_TOOBIG:
 587                 if (rel_code != 0)
 588                         return 0;
 589                 rel_type = ICMP_DEST_UNREACH;
 590                 rel_code = ICMP_FRAG_NEEDED;
 591                 break;
 592         default:
 593                 return 0;
 594         }
 595
 596         if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
 597                 return 0;
 598
 599         skb2 = skb_clone(skb, GFP_ATOMIC);
 600         if (!skb2)
 601                 return 0;
 602
 603         skb_dst_drop(skb2);
 604
 605         skb_pull(skb2, offset);
 606         skb_reset_network_header(skb2);
 607         eiph = ip_hdr(skb2);
 608
 609         /* Try to guess incoming interface */
 610         rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, eiph->saddr,
 611                                    0, 0, 0, IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 612         if (IS_ERR(rt))
 613                 goto out;
 614
 615         skb2->dev = rt->dst.dev;
 616         ip_rt_put(rt);
 617
 618         /* route "incoming" packet */
 619         if (rt->rt_flags & RTCF_LOCAL) {
 620                 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL,
 621                                            eiph->daddr, eiph->saddr, 0, 0,
 622                                            IPPROTO_IPIP, RT_TOS(eiph->tos), 0);
 623                 if (IS_ERR(rt) || rt->dst.dev->type != ARPHRD_TUNNEL6) {
 624                         if (!IS_ERR(rt))
 625                                 ip_rt_put(rt);
 626                         goto out;
 627                 }
 628                 skb_dst_set(skb2, &rt->dst);
 629         } else {
 630                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
 631                                    skb2->dev) ||
 632                     skb_dst(skb2)->dev->type != ARPHRD_TUNNEL6)
 633                         goto out;
 634         }
 635
 636         /* change mtu on this route */
 637         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
 638                 if (rel_info > dst_mtu(skb_dst(skb2)))
 639                         goto out;
 640
 641                 skb_dst_update_pmtu_no_confirm(skb2, rel_info);
 642         }
 643
 644         icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
 645
 646 out:
 647         kfree_skb(skb2);
 648         return 0;
 649 }
 650
 651 static int
 652 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 653            u8 type, u8 code, int offset, __be32 info)
 654 {
 655         __u32 rel_info = ntohl(info);
 656         int err, rel_msg = 0;
 657         u8 rel_type = type;
 658         u8 rel_code = code;
 659
 660         err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
 661                           &rel_msg, &rel_info, offset);
 662         if (err < 0)
 663                 return err;
 664
 665         if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
 666                 struct rt6_info *rt;
 667                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 668
 669                 if (!skb2)
 670                         return 0;
 671
 672                 skb_dst_drop(skb2);
 673                 skb_pull(skb2, offset);
 674                 skb_reset_network_header(skb2);
 675
 676                 /* Try to guess incoming interface */
 677                 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
 678                                 NULL, 0, skb2, 0);
 679
 680                 if (rt && rt->dst.dev)
 681                         skb2->dev = rt->dst.dev;
 682
 683                 icmpv6_send(skb2, rel_type, rel_code, rel_info);
 684
 685                 ip6_rt_put(rt);
 686
 687                 kfree_skb(skb2);
 688         }
 689
 690         return 0;
 691 }
 692
 693 static int
 694 mplsip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 695             u8 type, u8 code, int offset, __be32 info)
 696 {
 697         __u32 rel_info = ntohl(info);
 698         int err, rel_msg = 0;
 699         u8 rel_type = type;
 700         u8 rel_code = code;
 701
 702         err = ip6_tnl_err(skb, IPPROTO_MPLS, opt, &rel_type, &rel_code,
 703                           &rel_msg, &rel_info, offset);
 704         return err;
 705 }
 706
 707 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 708                                        const struct ipv6hdr *ipv6h,
 709                                        struct sk_buff *skb)
 710 {
 711         __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
 712
 713         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 714                 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
 715
 716         return IP6_ECN_decapsulate(ipv6h, skb);
 717 }
 718
 719 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 720                                        const struct ipv6hdr *ipv6h,
 721                                        struct sk_buff *skb)
 722 {
 723         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 724                 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb));
 725
 726         return IP6_ECN_decapsulate(ipv6h, skb);
 727 }
 728
 729 static inline int mplsip6_dscp_ecn_decapsulate(const struct ip6_tnl *t,
 730                                                const struct ipv6hdr *ipv6h,
 731                                                struct sk_buff *skb)
 732 {
 733         /* ECN is not supported in AF_MPLS */
 734         return 0;
 735 }
 736
 737 __u32 ip6_tnl_get_cap(struct ip6_tnl *t,
 738                              const struct in6_addr *laddr,
 739                              const struct in6_addr *raddr)
 740 {
 741         struct __ip6_tnl_parm *p = &t->parms;
 742         int ltype = ipv6_addr_type(laddr);
 743         int rtype = ipv6_addr_type(raddr);
 744         __u32 flags = 0;
 745
 746         if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) {
 747                 flags = IP6_TNL_F_CAP_PER_PACKET;
 748         } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 749                    rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
 750                    !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
 751                    (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
 752                 if (ltype&IPV6_ADDR_UNICAST)
 753                         flags |= IP6_TNL_F_CAP_XMIT;
 754                 if (rtype&IPV6_ADDR_UNICAST)
 755                         flags |= IP6_TNL_F_CAP_RCV;
 756         }
 757         return flags;
 758 }
 759 EXPORT_SYMBOL(ip6_tnl_get_cap);
 760
 761 /* called with rcu_read_lock() */
 762 int ip6_tnl_rcv_ctl(struct ip6_tnl *t,
 763                                   const struct in6_addr *laddr,
 764                                   const struct in6_addr *raddr)
 765 {
 766         struct __ip6_tnl_parm *p = &t->parms;
 767         int ret = 0;
 768         struct net *net = t->net;
 769
 770         if ((p->flags & IP6_TNL_F_CAP_RCV) ||
 771             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
 772              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) {
 773                 struct net_device *ldev = NULL;
 774
 775                 if (p->link)
 776                         ldev = dev_get_by_index_rcu(net, p->link);
 777
 778                 if ((ipv6_addr_is_multicast(laddr) ||
 779                      likely(ipv6_chk_addr_and_flags(net, laddr, ldev, false,
 780                                                     0, IFA_F_TENTATIVE))) &&
 781                     ((p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) ||
 782                      likely(!ipv6_chk_addr_and_flags(net, raddr, ldev, true,
 783                                                      0, IFA_F_TENTATIVE))))
 784                         ret = 1;
 785         }
 786         return ret;
 787 }
 788 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl);
 789
 790 static int __ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
 791                          const struct tnl_ptk_info *tpi,
 792                          struct metadata_dst *tun_dst,
 793                          int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 794                                                 const struct ipv6hdr *ipv6h,
 795                                                 struct sk_buff *skb),
 796                          bool log_ecn_err)
 797 {
 798         const struct ipv6hdr *ipv6h;
 799         int nh, err;
 800
 801         if (test_bit(IP_TUNNEL_CSUM_BIT, tunnel->parms.i_flags) !=
 802             test_bit(IP_TUNNEL_CSUM_BIT, tpi->flags)) {
 803                 DEV_STATS_INC(tunnel->dev, rx_crc_errors);
 804                 DEV_STATS_INC(tunnel->dev, rx_errors);
 805                 goto drop;
 806         }
 807
 808         if (test_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.i_flags)) {
 809                 if (!test_bit(IP_TUNNEL_SEQ_BIT, tpi->flags) ||
 810                     (tunnel->i_seqno &&
 811                      (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) {
 812                         DEV_STATS_INC(tunnel->dev, rx_fifo_errors);
 813                         DEV_STATS_INC(tunnel->dev, rx_errors);
 814                         goto drop;
 815                 }
 816                 tunnel->i_seqno = ntohl(tpi->seq) + 1;
 817         }
 818
 819         skb->protocol = tpi->proto;
 820
 821         /* Warning: All skb pointers will be invalidated! */
 822         if (tunnel->dev->type == ARPHRD_ETHER) {
 823                 if (!pskb_may_pull(skb, ETH_HLEN)) {
 824                         DEV_STATS_INC(tunnel->dev, rx_length_errors);
 825                         DEV_STATS_INC(tunnel->dev, rx_errors);
 826                         goto drop;
 827                 }
 828
 829                 skb->protocol = eth_type_trans(skb, tunnel->dev);
 830                 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
 831         } else {
 832                 skb->dev = tunnel->dev;
 833                 skb_reset_mac_header(skb);
 834         }
 835
 836         /* Save offset of outer header relative to skb->head,
 837          * because we are going to reset the network header to the inner header
 838          * and might change skb->head.
 839          */
 840         nh = skb_network_header(skb) - skb->head;
 841
 842         skb_reset_network_header(skb);
 843
 844         if (!pskb_inet_may_pull(skb)) {
 845                 DEV_STATS_INC(tunnel->dev, rx_length_errors);
 846                 DEV_STATS_INC(tunnel->dev, rx_errors);
 847                 goto drop;
 848         }
 849
 850         /* Get the outer header. */
 851         ipv6h = (struct ipv6hdr *)(skb->head + nh);
 852
 853         memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 854
 855         __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 856
 857         err = dscp_ecn_decapsulate(tunnel, ipv6h, skb);
 858         if (unlikely(err)) {
 859                 if (log_ecn_err)
 860                         net_info_ratelimited("non-ECT from %pI6 with DS=%#x\n",
 861                                              &ipv6h->saddr,
 862                                              ipv6_get_dsfield(ipv6h));
 863                 if (err > 1) {
 864                         DEV_STATS_INC(tunnel->dev, rx_frame_errors);
 865                         DEV_STATS_INC(tunnel->dev, rx_errors);
 866                         goto drop;
 867                 }
 868         }
 869
 870         dev_sw_netstats_rx_add(tunnel->dev, skb->len);
 871
 872         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev)));
 873
 874         if (tun_dst)
 875                 skb_dst_set(skb, (struct dst_entry *)tun_dst);
 876
 877         gro_cells_receive(&tunnel->gro_cells, skb);
 878         return 0;
 879
 880 drop:
 881         if (tun_dst)
 882                 dst_release((struct dst_entry *)tun_dst);
 883         kfree_skb(skb);
 884         return 0;
 885 }
 886
 887 int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb,
 888                 const struct tnl_ptk_info *tpi,
 889                 struct metadata_dst *tun_dst,
 890                 bool log_ecn_err)
 891 {
 892         int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 893                                     const struct ipv6hdr *ipv6h,
 894                                     struct sk_buff *skb);
 895
 896         dscp_ecn_decapsulate = ip6ip6_dscp_ecn_decapsulate;
 897         if (tpi->proto == htons(ETH_P_IP))
 898                 dscp_ecn_decapsulate = ip4ip6_dscp_ecn_decapsulate;
 899
 900         return __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
 901                              log_ecn_err);
 902 }
 903 EXPORT_SYMBOL(ip6_tnl_rcv);
 904
 905 static const struct tnl_ptk_info tpi_v6 = {
 906         /* no tunnel info required for ipxip6. */
 907         .proto = htons(ETH_P_IPV6),
 908 };
 909
 910 static const struct tnl_ptk_info tpi_v4 = {
 911         /* no tunnel info required for ipxip6. */
 912         .proto = htons(ETH_P_IP),
 913 };
 914
 915 static const struct tnl_ptk_info tpi_mpls = {
 916         /* no tunnel info required for mplsip6. */
 917         .proto = htons(ETH_P_MPLS_UC),
 918 };
 919
 920 static int ipxip6_rcv(struct sk_buff *skb, u8 ipproto,
 921                       const struct tnl_ptk_info *tpi,
 922                       int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,
 923                                                   const struct ipv6hdr *ipv6h,
 924                                                   struct sk_buff *skb))
 925 {
 926         struct ip6_tnl *t;
 927         const struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 928         struct metadata_dst *tun_dst = NULL;
 929         int ret = -1;
 930
 931         rcu_read_lock();
 932         t = ip6_tnl_lookup(dev_net(skb->dev), skb->dev->ifindex, &ipv6h->saddr, &ipv6h->daddr);
 933
 934         if (t) {
 935                 u8 tproto = READ_ONCE(t->parms.proto);
 936
 937                 if (tproto != ipproto && tproto != 0)
 938                         goto drop;
 939                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
 940                         goto drop;
 941                 ipv6h = ipv6_hdr(skb);
 942                 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr))
 943                         goto drop;
 944                 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
 945                         goto drop;
 946                 if (t->parms.collect_md) {
 947                         IP_TUNNEL_DECLARE_FLAGS(flags) = { };
 948
 949                         tun_dst = ipv6_tun_rx_dst(skb, flags, 0, 0);
 950                         if (!tun_dst)
 951                                 goto drop;
 952                 }
 953                 ret = __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,
 954                                     log_ecn_error);
 955         }
 956
 957         rcu_read_unlock();
 958
 959         return ret;
 960
 961 drop:
 962         rcu_read_unlock();
 963         kfree_skb(skb);
 964         return 0;
 965 }
 966
 967 static int ip4ip6_rcv(struct sk_buff *skb)
 968 {
 969         return ipxip6_rcv(skb, IPPROTO_IPIP, &tpi_v4,
 970                           ip4ip6_dscp_ecn_decapsulate);
 971 }
 972
 973 static int ip6ip6_rcv(struct sk_buff *skb)
 974 {
 975         return ipxip6_rcv(skb, IPPROTO_IPV6, &tpi_v6,
 976                           ip6ip6_dscp_ecn_decapsulate);
 977 }
 978
 979 static int mplsip6_rcv(struct sk_buff *skb)
 980 {
 981         return ipxip6_rcv(skb, IPPROTO_MPLS, &tpi_mpls,
 982                           mplsip6_dscp_ecn_decapsulate);
 983 }
 984
 985 struct ipv6_tel_txoption {
 986         struct ipv6_txoptions ops;
 987         __u8 dst_opt[8];
 988 };
 989
 990 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 991 {
 992         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 993
 994         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 995         opt->dst_opt[3] = 1;
 996         opt->dst_opt[4] = encap_limit;
 997         opt->dst_opt[5] = IPV6_TLV_PADN;
 998         opt->dst_opt[6] = 1;
 999
1000         opt->ops.dst1opt = (struct ipv6_opt_hdr *) opt->dst_opt;
1001         opt->ops.opt_nflen = 8;
1002 }
1003
1004 /**
1005  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
1006  *   @t: the outgoing tunnel device
1007  *   @hdr: IPv6 header from the incoming packet
1008  *
1009  * Description:
1010  *   Avoid trivial tunneling loop by checking that tunnel exit-point
1011  *   doesn't match source of incoming packet.
1012  *
1013  * Return:
1014  *   1 if conflict,
1015  *   0 else
1016  **/
1017
1018 static inline bool
1019 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr)
1020 {
1021         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
1022 }
1023
1024 int ip6_tnl_xmit_ctl(struct ip6_tnl *t,
1025                      const struct in6_addr *laddr,
1026                      const struct in6_addr *raddr)
1027 {
1028         struct __ip6_tnl_parm *p = &t->parms;
1029         int ret = 0;
1030         struct net *net = t->net;
1031
1032         if (t->parms.collect_md)
1033                 return 1;
1034
1035         if ((p->flags & IP6_TNL_F_CAP_XMIT) ||
1036             ((p->flags & IP6_TNL_F_CAP_PER_PACKET) &&
1037              (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_XMIT))) {
1038                 struct net_device *ldev = NULL;
1039
1040                 rcu_read_lock();
1041                 if (p->link)
1042                         ldev = dev_get_by_index_rcu(net, p->link);
1043
1044                 if (unlikely(!ipv6_chk_addr_and_flags(net, laddr, ldev, false,
1045                                                       0, IFA_F_TENTATIVE)))
1046                         pr_warn_ratelimited("%s xmit: Local address not yet configured!\n",
1047                                             p->name);
1048                 else if (!(p->flags & IP6_TNL_F_ALLOW_LOCAL_REMOTE) &&
1049                          !ipv6_addr_is_multicast(raddr) &&
1050                          unlikely(ipv6_chk_addr_and_flags(net, raddr, ldev,
1051                                                           true, 0, IFA_F_TENTATIVE)))
1052                         pr_warn_ratelimited("%s xmit: Routing loop! Remote address found on this node!\n",
1053                                             p->name);
1054                 else
1055                         ret = 1;
1056                 rcu_read_unlock();
1057         }
1058         return ret;
1059 }
1060 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl);
1061
1062 /**
1063  * ip6_tnl_xmit - encapsulate packet and send
1064  *   @skb: the outgoing socket buffer
1065  *   @dev: the outgoing tunnel device
1066  *   @dsfield: dscp code for outer header
1067  *   @fl6: flow of tunneled packet
1068  *   @encap_limit: encapsulation limit
1069  *   @pmtu: Path MTU is stored if packet is too big
1070  *   @proto: next header value
1071  *
1072  * Description:
1073  *   Build new header and do some sanity checks on the packet before sending
1074  *   it.
1075  *
1076  * Return:
1077  *   0 on success
1078  *   -1 fail
1079  *   %-EMSGSIZE message too big. return mtu in this case.
1080  **/
1081
1082 int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
1083                  struct flowi6 *fl6, int encap_limit, __u32 *pmtu,
1084                  __u8 proto)
1085 {
1086         struct ip6_tnl *t = netdev_priv(dev);
1087         struct net *net = t->net;
1088         struct ipv6hdr *ipv6h;
1089         struct ipv6_tel_txoption opt;
1090         struct dst_entry *dst = NULL, *ndst = NULL;
1091         struct net_device *tdev;
1092         int mtu;
1093         unsigned int eth_hlen = t->dev->type == ARPHRD_ETHER ? ETH_HLEN : 0;
1094         unsigned int psh_hlen = sizeof(struct ipv6hdr) + t->encap_hlen;
1095         unsigned int max_headroom = psh_hlen;
1096         __be16 payload_protocol;
1097         bool use_cache = false;
1098         u8 hop_limit;
1099         int err = -1;
1100
1101         payload_protocol = skb_protocol(skb, true);
1102
1103         if (t->parms.collect_md) {
1104                 hop_limit = skb_tunnel_info(skb)->key.ttl;
1105                 goto route_lookup;
1106         } else {
1107                 hop_limit = t->parms.hop_limit;
1108         }
1109
1110         /* NBMA tunnel */
1111         if (ipv6_addr_any(&t->parms.raddr)) {
1112                 if (payload_protocol == htons(ETH_P_IPV6)) {
1113                         struct in6_addr *addr6;
1114                         struct neighbour *neigh;
1115                         int addr_type;
1116
1117                         if (!skb_dst(skb))
1118                                 goto tx_err_link_failure;
1119
1120                         neigh = dst_neigh_lookup(skb_dst(skb),
1121                                                  &ipv6_hdr(skb)->daddr);
1122                         if (!neigh)
1123                                 goto tx_err_link_failure;
1124
1125                         addr6 = (struct in6_addr *)&neigh->primary_key;
1126                         addr_type = ipv6_addr_type(addr6);
1127
1128                         if (addr_type == IPV6_ADDR_ANY)
1129                                 addr6 = &ipv6_hdr(skb)->daddr;
1130
1131                         memcpy(&fl6->daddr, addr6, sizeof(fl6->daddr));
1132                         neigh_release(neigh);
1133                 } else if (payload_protocol == htons(ETH_P_IP)) {
1134                         const struct rtable *rt = skb_rtable(skb);
1135
1136                         if (!rt)
1137                                 goto tx_err_link_failure;
1138
1139                         if (rt->rt_gw_family == AF_INET6)
1140                                 memcpy(&fl6->daddr, &rt->rt_gw6, sizeof(fl6->daddr));
1141                 }
1142         } else if (t->parms.proto != 0 && !(t->parms.flags &
1143                                             (IP6_TNL_F_USE_ORIG_TCLASS |
1144                                              IP6_TNL_F_USE_ORIG_FWMARK))) {
1145                 /* enable the cache only if neither the outer protocol nor the
1146                  * routing decision depends on the current inner header value
1147                  */
1148                 use_cache = true;
1149         }
1150
1151         if (use_cache)
1152                 dst = dst_cache_get(&t->dst_cache);
1153
1154         if (!ip6_tnl_xmit_ctl(t, &fl6->saddr, &fl6->daddr))
1155                 goto tx_err_link_failure;
1156
1157         if (!dst) {
1158 route_lookup:
1159                 /* add dsfield to flowlabel for route lookup */
1160                 fl6->flowlabel = ip6_make_flowinfo(dsfield, fl6->flowlabel);
1161
1162                 dst = ip6_route_output(net, NULL, fl6);
1163
1164                 if (dst->error)
1165                         goto tx_err_link_failure;
1166                 dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), NULL, 0);
1167                 if (IS_ERR(dst)) {
1168                         err = PTR_ERR(dst);
1169                         dst = NULL;
1170                         goto tx_err_link_failure;
1171                 }
1172                 if (t->parms.collect_md && ipv6_addr_any(&fl6->saddr) &&
1173                     ipv6_dev_get_saddr(net, ip6_dst_idev(dst)->dev,
1174                                        &fl6->daddr, 0, &fl6->saddr))
1175                         goto tx_err_link_failure;
1176                 ndst = dst;
1177         }
1178
1179         tdev = dst->dev;
1180
1181         if (tdev == dev) {
1182                 DEV_STATS_INC(dev, collisions);
1183                 net_warn_ratelimited("%s: Local routing loop detected!\n",
1184                                      t->parms.name);
1185                 goto tx_err_dst_release;
1186         }
1187         mtu = dst_mtu(dst) - eth_hlen - psh_hlen - t->tun_hlen;
1188         if (encap_limit >= 0) {
1189                 max_headroom += 8;
1190                 mtu -= 8;
1191         }
1192         mtu = max(mtu, skb->protocol == htons(ETH_P_IPV6) ?
1193                        IPV6_MIN_MTU : IPV4_MIN_MTU);
1194
1195         skb_dst_update_pmtu_no_confirm(skb, mtu);
1196         if (skb->len - t->tun_hlen - eth_hlen > mtu && !skb_is_gso(skb)) {
1197                 *pmtu = mtu;
1198                 err = -EMSGSIZE;
1199                 goto tx_err_dst_release;
1200         }
1201
1202         if (t->err_count > 0) {
1203                 if (time_before(jiffies,
1204                                 t->err_time + IP6TUNNEL_ERR_TIMEO)) {
1205                         t->err_count--;
1206
1207                         dst_link_failure(skb);
1208                 } else {
1209                         t->err_count = 0;
1210                 }
1211         }
1212
1213         skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev)));
1214
1215         /*
1216          * Okay, now see if we can stuff it in the buffer as-is.
1217          */
1218         max_headroom += LL_RESERVED_SPACE(tdev);
1219
1220         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1221             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1222                 struct sk_buff *new_skb;
1223
1224                 new_skb = skb_realloc_headroom(skb, max_headroom);
1225                 if (!new_skb)
1226                         goto tx_err_dst_release;
1227
1228                 if (skb->sk)
1229                         skb_set_owner_w(new_skb, skb->sk);
1230                 consume_skb(skb);
1231                 skb = new_skb;
1232         }
1233
1234         if (t->parms.collect_md) {
1235                 if (t->encap.type != TUNNEL_ENCAP_NONE)
1236                         goto tx_err_dst_release;
1237         } else {
1238                 if (use_cache && ndst)
1239                         dst_cache_set_ip6(&t->dst_cache, ndst, &fl6->saddr);
1240         }
1241         skb_dst_set(skb, dst);
1242
1243         if (hop_limit == 0) {
1244                 if (payload_protocol == htons(ETH_P_IP))
1245                         hop_limit = ip_hdr(skb)->ttl;
1246                 else if (payload_protocol == htons(ETH_P_IPV6))
1247                         hop_limit = ipv6_hdr(skb)->hop_limit;
1248                 else
1249                         hop_limit = ip6_dst_hoplimit(dst);
1250         }
1251
1252         /* Calculate max headroom for all the headers and adjust
1253          * needed_headroom if necessary.
1254          */
1255         max_headroom = LL_RESERVED_SPACE(dst->dev) + sizeof(struct ipv6hdr)
1256                         + dst->header_len + t->hlen;
1257         if (max_headroom > READ_ONCE(dev->needed_headroom))
1258                 WRITE_ONCE(dev->needed_headroom, max_headroom);
1259
1260         err = ip6_tnl_encap(skb, t, &proto, fl6);
1261         if (err)
1262                 return err;
1263
1264         if (encap_limit >= 0) {
1265                 init_tel_txopt(&opt, encap_limit);
1266                 ipv6_push_frag_opts(skb, &opt.ops, &proto);
1267         }
1268
1269         skb_push(skb, sizeof(struct ipv6hdr));
1270         skb_reset_network_header(skb);
1271         ipv6h = ipv6_hdr(skb);
1272         ip6_flow_hdr(ipv6h, dsfield,
1273                      ip6_make_flowlabel(net, skb, fl6->flowlabel, true, fl6));
1274         ipv6h->hop_limit = hop_limit;
1275         ipv6h->nexthdr = proto;
1276         ipv6h->saddr = fl6->saddr;
1277         ipv6h->daddr = fl6->daddr;
1278         ip6tunnel_xmit(NULL, skb, dev);
1279         return 0;
1280 tx_err_link_failure:
1281         DEV_STATS_INC(dev, tx_carrier_errors);
1282         dst_link_failure(skb);
1283 tx_err_dst_release:
1284         dst_release(dst);
1285         return err;
1286 }
1287 EXPORT_SYMBOL(ip6_tnl_xmit);
1288
1289 static inline int
1290 ipxip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev,
1291                 u8 protocol)
1292 {
1293         struct ip6_tnl *t = netdev_priv(dev);
1294         struct ipv6hdr *ipv6h;
1295         const struct iphdr  *iph;
1296         int encap_limit = -1;
1297         __u16 offset;
1298         struct flowi6 fl6;
1299         __u8 dsfield, orig_dsfield;
1300         __u32 mtu;
1301         u8 tproto;
1302         int err;
1303
1304         tproto = READ_ONCE(t->parms.proto);
1305         if (tproto != protocol && tproto != 0)
1306                 return -1;
1307
1308         if (t->parms.collect_md) {
1309                 struct ip_tunnel_info *tun_info;
1310                 const struct ip_tunnel_key *key;
1311
1312                 tun_info = skb_tunnel_info(skb);
1313                 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
1314                              ip_tunnel_info_af(tun_info) != AF_INET6))
1315                         return -1;
1316                 key = &tun_info->key;
1317                 memset(&fl6, 0, sizeof(fl6));
1318                 fl6.flowi6_proto = protocol;
1319                 fl6.saddr = key->u.ipv6.src;
1320                 fl6.daddr = key->u.ipv6.dst;
1321                 fl6.flowlabel = key->label;
1322                 dsfield =  key->tos;
1323                 switch (protocol) {
1324                 case IPPROTO_IPIP:
1325                         iph = ip_hdr(skb);
1326                         orig_dsfield = ipv4_get_dsfield(iph);
1327                         break;
1328                 case IPPROTO_IPV6:
1329                         ipv6h = ipv6_hdr(skb);
1330                         orig_dsfield = ipv6_get_dsfield(ipv6h);
1331                         break;
1332                 default:
1333                         orig_dsfield = dsfield;
1334                         break;
1335                 }
1336         } else {
1337                 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1338                         encap_limit = t->parms.encap_limit;
1339                 if (protocol == IPPROTO_IPV6) {
1340                         offset = ip6_tnl_parse_tlv_enc_lim(skb,
1341                                                 skb_network_header(skb));
1342                         /* ip6_tnl_parse_tlv_enc_lim() might have
1343                          * reallocated skb->head
1344                          */
1345                         if (offset > 0) {
1346                                 struct ipv6_tlv_tnl_enc_lim *tel;
1347
1348                                 tel = (void *)&skb_network_header(skb)[offset];
1349                                 if (tel->encap_limit == 0) {
1350                                         icmpv6_ndo_send(skb, ICMPV6_PARAMPROB,
1351                                                         ICMPV6_HDR_FIELD, offset + 2);
1352                                         return -1;
1353                                 }
1354                                 encap_limit = tel->encap_limit - 1;
1355                         }
1356                 }
1357
1358                 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6));
1359                 fl6.flowi6_proto = protocol;
1360
1361                 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
1362                         fl6.flowi6_mark = skb->mark;
1363                 else
1364                         fl6.flowi6_mark = t->parms.fwmark;
1365                 switch (protocol) {
1366                 case IPPROTO_IPIP:
1367                         iph = ip_hdr(skb);
1368                         orig_dsfield = ipv4_get_dsfield(iph);
1369                         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1370                                 dsfield = orig_dsfield;
1371                         else
1372                                 dsfield = ip6_tclass(t->parms.flowinfo);
1373                         break;
1374                 case IPPROTO_IPV6:
1375                         ipv6h = ipv6_hdr(skb);
1376                         orig_dsfield = ipv6_get_dsfield(ipv6h);
1377                         if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
1378                                 dsfield = orig_dsfield;
1379                         else
1380                                 dsfield = ip6_tclass(t->parms.flowinfo);
1381                         if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
1382                                 fl6.flowlabel |= ip6_flowlabel(ipv6h);
1383                         break;
1384                 default:
1385                         orig_dsfield = dsfield = ip6_tclass(t->parms.flowinfo);
1386                         break;
1387                 }
1388         }
1389
1390         fl6.flowi6_uid = sock_net_uid(dev_net(dev), NULL);
1391         dsfield = INET_ECN_encapsulate(dsfield, orig_dsfield);
1392
1393         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP6))
1394                 return -1;
1395
1396         skb_set_inner_ipproto(skb, protocol);
1397
1398         err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu,
1399                            protocol);
1400         if (err != 0) {
1401                 /* XXX: send ICMP error even if DF is not set. */
1402                 if (err == -EMSGSIZE)
1403                         switch (protocol) {
1404                         case IPPROTO_IPIP:
1405                                 icmp_ndo_send(skb, ICMP_DEST_UNREACH,
1406                                               ICMP_FRAG_NEEDED, htonl(mtu));
1407                                 break;
1408                         case IPPROTO_IPV6:
1409                                 icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1410                                 break;
1411                         default:
1412                                 break;
1413                         }
1414                 return -1;
1415         }
1416
1417         return 0;
1418 }
1419
1420 static netdev_tx_t
1421 ip6_tnl_start_xmit(struct sk_buff *skb, struct net_device *dev)
1422 {
1423         struct ip6_tnl *t = netdev_priv(dev);
1424         u8 ipproto;
1425         int ret;
1426
1427         if (!pskb_inet_may_pull(skb))
1428                 goto tx_err;
1429
1430         switch (skb->protocol) {
1431         case htons(ETH_P_IP):
1432                 ipproto = IPPROTO_IPIP;
1433                 break;
1434         case htons(ETH_P_IPV6):
1435                 if (ip6_tnl_addr_conflict(t, ipv6_hdr(skb)))
1436                         goto tx_err;
1437                 ipproto = IPPROTO_IPV6;
1438                 break;
1439         case htons(ETH_P_MPLS_UC):
1440                 ipproto = IPPROTO_MPLS;
1441                 break;
1442         default:
1443                 goto tx_err;
1444         }
1445
1446         ret = ipxip6_tnl_xmit(skb, dev, ipproto);
1447         if (ret < 0)
1448                 goto tx_err;
1449
1450         return NETDEV_TX_OK;
1451
1452 tx_err:
1453         DEV_STATS_INC(dev, tx_errors);
1454         DEV_STATS_INC(dev, tx_dropped);
1455         kfree_skb(skb);
1456         return NETDEV_TX_OK;
1457 }
1458
1459 static void ip6_tnl_link_config(struct ip6_tnl *t)
1460 {
1461         struct net_device *dev = t->dev;
1462         struct net_device *tdev = NULL;
1463         struct __ip6_tnl_parm *p = &t->parms;
1464         struct flowi6 *fl6 = &t->fl.u.ip6;
1465         int t_hlen;
1466         int mtu;
1467
1468         __dev_addr_set(dev, &p->laddr, sizeof(struct in6_addr));
1469         memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1470
1471         /* Set up flowi template */
1472         fl6->saddr = p->laddr;
1473         fl6->daddr = p->raddr;
1474         fl6->flowi6_oif = p->link;
1475         fl6->flowlabel = 0;
1476
1477         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1478                 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1479         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1480                 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1481
1482         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET);
1483         p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr);
1484
1485         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1486                 dev->flags |= IFF_POINTOPOINT;
1487         else
1488                 dev->flags &= ~IFF_POINTOPOINT;
1489
1490         t->tun_hlen = 0;
1491         t->hlen = t->encap_hlen + t->tun_hlen;
1492         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1493
1494         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1495                 int strict = (ipv6_addr_type(&p->raddr) &
1496                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1497
1498                 struct rt6_info *rt = rt6_lookup(t->net,
1499                                                  &p->raddr, &p->laddr,
1500                                                  p->link, NULL, strict);
1501                 if (rt) {
1502                         tdev = rt->dst.dev;
1503                         ip6_rt_put(rt);
1504                 }
1505
1506                 if (!tdev && p->link)
1507                         tdev = __dev_get_by_index(t->net, p->link);
1508
1509                 if (tdev) {
1510                         dev->hard_header_len = tdev->hard_header_len + t_hlen;
1511                         mtu = min_t(unsigned int, tdev->mtu, IP6_MAX_MTU);
1512
1513                         mtu = mtu - t_hlen;
1514                         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1515                                 mtu -= 8;
1516
1517                         if (mtu < IPV6_MIN_MTU)
1518                                 mtu = IPV6_MIN_MTU;
1519                         WRITE_ONCE(dev->mtu, mtu);
1520                 }
1521         }
1522 }
1523
1524 /**
1525  * ip6_tnl_change - update the tunnel parameters
1526  *   @t: tunnel to be changed
1527  *   @p: tunnel configuration parameters
1528  *
1529  * Description:
1530  *   ip6_tnl_change() updates the tunnel parameters
1531  **/
1532
1533 static void
1534 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p)
1535 {
1536         t->parms.laddr = p->laddr;
1537         t->parms.raddr = p->raddr;
1538         t->parms.flags = p->flags;
1539         t->parms.hop_limit = p->hop_limit;
1540         t->parms.encap_limit = p->encap_limit;
1541         t->parms.flowinfo = p->flowinfo;
1542         t->parms.link = p->link;
1543         t->parms.proto = p->proto;
1544         t->parms.fwmark = p->fwmark;
1545         dst_cache_reset(&t->dst_cache);
1546         ip6_tnl_link_config(t);
1547 }
1548
1549 static void ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1550 {
1551         struct net *net = t->net;
1552         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1553
1554         ip6_tnl_unlink(ip6n, t);
1555         synchronize_net();
1556         ip6_tnl_change(t, p);
1557         ip6_tnl_link(ip6n, t);
1558         netdev_state_change(t->dev);
1559 }
1560
1561 static void ip6_tnl0_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p)
1562 {
1563         /* for default tnl0 device allow to change only the proto */
1564         t->parms.proto = p->proto;
1565         netdev_state_change(t->dev);
1566 }
1567
1568 static void
1569 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u)
1570 {
1571         p->laddr = u->laddr;
1572         p->raddr = u->raddr;
1573         p->flags = u->flags;
1574         p->hop_limit = u->hop_limit;
1575         p->encap_limit = u->encap_limit;
1576         p->flowinfo = u->flowinfo;
1577         p->link = u->link;
1578         p->proto = u->proto;
1579         memcpy(p->name, u->name, sizeof(u->name));
1580 }
1581
1582 static void
1583 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p)
1584 {
1585         u->laddr = p->laddr;
1586         u->raddr = p->raddr;
1587         u->flags = p->flags;
1588         u->hop_limit = p->hop_limit;
1589         u->encap_limit = p->encap_limit;
1590         u->flowinfo = p->flowinfo;
1591         u->link = p->link;
1592         u->proto = p->proto;
1593         memcpy(u->name, p->name, sizeof(u->name));
1594 }
1595
1596 /**
1597  * ip6_tnl_siocdevprivate - configure ipv6 tunnels from userspace
1598  *   @dev: virtual device associated with tunnel
1599  *   @ifr: unused
1600  *   @data: parameters passed from userspace
1601  *   @cmd: command to be performed
1602  *
1603  * Description:
1604  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1605  *   from userspace.
1606  *
1607  *   The possible commands are the following:
1608  *     %SIOCGETTUNNEL: get tunnel parameters for device
1609  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1610  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1611  *     %SIOCDELTUNNEL: delete tunnel
1612  *
1613  *   The fallback device "ip6tnl0", created during module
1614  *   initialization, can be used for creating other tunnel devices.
1615  *
1616  * Return:
1617  *   0 on success,
1618  *   %-EFAULT if unable to copy data to or from userspace,
1619  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1620  *   %-EINVAL if passed tunnel parameters are invalid,
1621  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1622  *   %-ENODEV if attempting to change or delete a nonexisting device
1623  **/
1624
1625 static int
1626 ip6_tnl_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
1627                        void __user *data, int cmd)
1628 {
1629         int err = 0;
1630         struct ip6_tnl_parm p;
1631         struct __ip6_tnl_parm p1;
1632         struct ip6_tnl *t = netdev_priv(dev);
1633         struct net *net = t->net;
1634         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1635
1636         memset(&p1, 0, sizeof(p1));
1637
1638         switch (cmd) {
1639         case SIOCGETTUNNEL:
1640                 if (dev == ip6n->fb_tnl_dev) {
1641                         if (copy_from_user(&p, data, sizeof(p))) {
1642                                 err = -EFAULT;
1643                                 break;
1644                         }
1645                         ip6_tnl_parm_from_user(&p1, &p);
1646                         t = ip6_tnl_locate(net, &p1, 0);
1647                         if (IS_ERR(t))
1648                                 t = netdev_priv(dev);
1649                 } else {
1650                         memset(&p, 0, sizeof(p));
1651                 }
1652                 ip6_tnl_parm_to_user(&p, &t->parms);
1653                 if (copy_to_user(data, &p, sizeof(p)))
1654                         err = -EFAULT;
1655                 break;
1656         case SIOCADDTUNNEL:
1657         case SIOCCHGTUNNEL:
1658                 err = -EPERM;
1659                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1660                         break;
1661                 err = -EFAULT;
1662                 if (copy_from_user(&p, data, sizeof(p)))
1663                         break;
1664                 err = -EINVAL;
1665                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1666                     p.proto != 0)
1667                         break;
1668                 ip6_tnl_parm_from_user(&p1, &p);
1669                 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL);
1670                 if (cmd == SIOCCHGTUNNEL) {
1671                         if (!IS_ERR(t)) {
1672                                 if (t->dev != dev) {
1673                                         err = -EEXIST;
1674                                         break;
1675                                 }
1676                         } else
1677                                 t = netdev_priv(dev);
1678                         if (dev == ip6n->fb_tnl_dev)
1679                                 ip6_tnl0_update(t, &p1);
1680                         else
1681                                 ip6_tnl_update(t, &p1);
1682                 }
1683                 if (!IS_ERR(t)) {
1684                         err = 0;
1685                         ip6_tnl_parm_to_user(&p, &t->parms);
1686                         if (copy_to_user(data, &p, sizeof(p)))
1687                                 err = -EFAULT;
1688
1689                 } else {
1690                         err = PTR_ERR(t);
1691                 }
1692                 break;
1693         case SIOCDELTUNNEL:
1694                 err = -EPERM;
1695                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1696                         break;
1697
1698                 if (dev == ip6n->fb_tnl_dev) {
1699                         err = -EFAULT;
1700                         if (copy_from_user(&p, data, sizeof(p)))
1701                                 break;
1702                         err = -ENOENT;
1703                         ip6_tnl_parm_from_user(&p1, &p);
1704                         t = ip6_tnl_locate(net, &p1, 0);
1705                         if (IS_ERR(t))
1706                                 break;
1707                         err = -EPERM;
1708                         if (t->dev == ip6n->fb_tnl_dev)
1709                                 break;
1710                         dev = t->dev;
1711                 }
1712                 err = 0;
1713                 unregister_netdevice(dev);
1714                 break;
1715         default:
1716                 err = -EINVAL;
1717         }
1718         return err;
1719 }
1720
1721 /**
1722  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1723  *   @dev: virtual device associated with tunnel
1724  *   @new_mtu: the new mtu
1725  *
1726  * Return:
1727  *   0 on success,
1728  *   %-EINVAL if mtu too small
1729  **/
1730
1731 int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1732 {
1733         struct ip6_tnl *tnl = netdev_priv(dev);
1734
1735         if (tnl->parms.proto == IPPROTO_IPV6) {
1736                 if (new_mtu < IPV6_MIN_MTU)
1737                         return -EINVAL;
1738         } else {
1739                 if (new_mtu < ETH_MIN_MTU)
1740                         return -EINVAL;
1741         }
1742         if (tnl->parms.proto == IPPROTO_IPV6 || tnl->parms.proto == 0) {
1743                 if (new_mtu > IP6_MAX_MTU - dev->hard_header_len)
1744                         return -EINVAL;
1745         } else {
1746                 if (new_mtu > IP_MAX_MTU - dev->hard_header_len)
1747                         return -EINVAL;
1748         }
1749         WRITE_ONCE(dev->mtu, new_mtu);
1750         return 0;
1751 }
1752 EXPORT_SYMBOL(ip6_tnl_change_mtu);
1753
1754 int ip6_tnl_get_iflink(const struct net_device *dev)
1755 {
1756         struct ip6_tnl *t = netdev_priv(dev);
1757
1758         return READ_ONCE(t->parms.link);
1759 }
1760 EXPORT_SYMBOL(ip6_tnl_get_iflink);
1761
1762 int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
1763                           unsigned int num)
1764 {
1765         if (num >= MAX_IPTUN_ENCAP_OPS)
1766                 return -ERANGE;
1767
1768         return !cmpxchg((const struct ip6_tnl_encap_ops **)
1769                         &ip6tun_encaps[num],
1770                         NULL, ops) ? 0 : -1;
1771 }
1772 EXPORT_SYMBOL(ip6_tnl_encap_add_ops);
1773
1774 int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
1775                           unsigned int num)
1776 {
1777         int ret;
1778
1779         if (num >= MAX_IPTUN_ENCAP_OPS)
1780                 return -ERANGE;
1781
1782         ret = (cmpxchg((const struct ip6_tnl_encap_ops **)
1783                        &ip6tun_encaps[num],
1784                        ops, NULL) == ops) ? 0 : -1;
1785
1786         synchronize_net();
1787
1788         return ret;
1789 }
1790 EXPORT_SYMBOL(ip6_tnl_encap_del_ops);
1791
1792 int ip6_tnl_encap_setup(struct ip6_tnl *t,
1793                         struct ip_tunnel_encap *ipencap)
1794 {
1795         int hlen;
1796
1797         memset(&t->encap, 0, sizeof(t->encap));
1798
1799         hlen = ip6_encap_hlen(ipencap);
1800         if (hlen < 0)
1801                 return hlen;
1802
1803         t->encap.type = ipencap->type;
1804         t->encap.sport = ipencap->sport;
1805         t->encap.dport = ipencap->dport;
1806         t->encap.flags = ipencap->flags;
1807
1808         t->encap_hlen = hlen;
1809         t->hlen = t->encap_hlen + t->tun_hlen;
1810
1811         return 0;
1812 }
1813 EXPORT_SYMBOL_GPL(ip6_tnl_encap_setup);
1814
1815 static const struct net_device_ops ip6_tnl_netdev_ops = {
1816         .ndo_init       = ip6_tnl_dev_init,
1817         .ndo_uninit     = ip6_tnl_dev_uninit,
1818         .ndo_start_xmit = ip6_tnl_start_xmit,
1819         .ndo_siocdevprivate = ip6_tnl_siocdevprivate,
1820         .ndo_change_mtu = ip6_tnl_change_mtu,
1821         .ndo_get_stats64 = dev_get_tstats64,
1822         .ndo_get_iflink = ip6_tnl_get_iflink,
1823 };
1824
1825 #define IPXIPX_FEATURES (NETIF_F_SG |           \
1826                          NETIF_F_FRAGLIST |     \
1827                          NETIF_F_HIGHDMA |      \
1828                          NETIF_F_GSO_SOFTWARE | \
1829                          NETIF_F_HW_CSUM)
1830
1831 /**
1832  * ip6_tnl_dev_setup - setup virtual tunnel device
1833  *   @dev: virtual device associated with tunnel
1834  *
1835  * Description:
1836  *   Initialize function pointers and device parameters
1837  **/
1838
1839 static void ip6_tnl_dev_setup(struct net_device *dev)
1840 {
1841         dev->netdev_ops = &ip6_tnl_netdev_ops;
1842         dev->header_ops = &ip_tunnel_header_ops;
1843         dev->needs_free_netdev = true;
1844         dev->priv_destructor = ip6_dev_free;
1845
1846         dev->type = ARPHRD_TUNNEL6;
1847         dev->flags |= IFF_NOARP;
1848         dev->addr_len = sizeof(struct in6_addr);
1849         dev->features |= NETIF_F_LLTX;
1850         dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
1851         netif_keep_dst(dev);
1852
1853         dev->features           |= IPXIPX_FEATURES;
1854         dev->hw_features        |= IPXIPX_FEATURES;
1855
1856         /* This perm addr will be used as interface identifier by IPv6 */
1857         dev->addr_assign_type = NET_ADDR_RANDOM;
1858         eth_random_addr(dev->perm_addr);
1859 }
1860
1861
1862 /**
1863  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1864  *   @dev: virtual device associated with tunnel
1865  **/
1866
1867 static inline int
1868 ip6_tnl_dev_init_gen(struct net_device *dev)
1869 {
1870         struct ip6_tnl *t = netdev_priv(dev);
1871         int ret;
1872         int t_hlen;
1873
1874         t->dev = dev;
1875         t->net = dev_net(dev);
1876
1877         ret = dst_cache_init(&t->dst_cache, GFP_KERNEL);
1878         if (ret)
1879                 return ret;
1880
1881         ret = gro_cells_init(&t->gro_cells, dev);
1882         if (ret)
1883                 goto destroy_dst;
1884
1885         t->tun_hlen = 0;
1886         t->hlen = t->encap_hlen + t->tun_hlen;
1887         t_hlen = t->hlen + sizeof(struct ipv6hdr);
1888
1889         dev->type = ARPHRD_TUNNEL6;
1890         dev->hard_header_len = LL_MAX_HEADER + t_hlen;
1891         dev->mtu = ETH_DATA_LEN - t_hlen;
1892         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1893                 dev->mtu -= 8;
1894         dev->min_mtu = ETH_MIN_MTU;
1895         dev->max_mtu = IP6_MAX_MTU - dev->hard_header_len;
1896
1897         netdev_hold(dev, &t->dev_tracker, GFP_KERNEL);
1898         netdev_lockdep_set_classes(dev);
1899         return 0;
1900
1901 destroy_dst:
1902         dst_cache_destroy(&t->dst_cache);
1903
1904         return ret;
1905 }
1906
1907 /**
1908  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1909  *   @dev: virtual device associated with tunnel
1910  **/
1911
1912 static int ip6_tnl_dev_init(struct net_device *dev)
1913 {
1914         struct ip6_tnl *t = netdev_priv(dev);
1915         int err = ip6_tnl_dev_init_gen(dev);
1916
1917         if (err)
1918                 return err;
1919         ip6_tnl_link_config(t);
1920         if (t->parms.collect_md)
1921                 netif_keep_dst(dev);
1922         return 0;
1923 }
1924
1925 /**
1926  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1927  *   @dev: fallback device
1928  *
1929  * Return: 0
1930  **/
1931
1932 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev)
1933 {
1934         struct ip6_tnl *t = netdev_priv(dev);
1935         struct net *net = dev_net(dev);
1936         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
1937
1938         t->parms.proto = IPPROTO_IPV6;
1939
1940         rcu_assign_pointer(ip6n->tnls_wc[0], t);
1941         return 0;
1942 }
1943
1944 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[],
1945                             struct netlink_ext_ack *extack)
1946 {
1947         u8 proto;
1948
1949         if (!data || !data[IFLA_IPTUN_PROTO])
1950                 return 0;
1951
1952         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1953         if (proto != IPPROTO_IPV6 &&
1954             proto != IPPROTO_IPIP &&
1955             proto != 0)
1956                 return -EINVAL;
1957
1958         return 0;
1959 }
1960
1961 static void ip6_tnl_netlink_parms(struct nlattr *data[],
1962                                   struct __ip6_tnl_parm *parms)
1963 {
1964         memset(parms, 0, sizeof(*parms));
1965
1966         if (!data)
1967                 return;
1968
1969         if (data[IFLA_IPTUN_LINK])
1970                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1971
1972         if (data[IFLA_IPTUN_LOCAL])
1973                 parms->laddr = nla_get_in6_addr(data[IFLA_IPTUN_LOCAL]);
1974
1975         if (data[IFLA_IPTUN_REMOTE])
1976                 parms->raddr = nla_get_in6_addr(data[IFLA_IPTUN_REMOTE]);
1977
1978         if (data[IFLA_IPTUN_TTL])
1979                 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]);
1980
1981         if (data[IFLA_IPTUN_ENCAP_LIMIT])
1982                 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]);
1983
1984         if (data[IFLA_IPTUN_FLOWINFO])
1985                 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]);
1986
1987         if (data[IFLA_IPTUN_FLAGS])
1988                 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]);
1989
1990         if (data[IFLA_IPTUN_PROTO])
1991                 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1992
1993         if (data[IFLA_IPTUN_COLLECT_METADATA])
1994                 parms->collect_md = true;
1995
1996         if (data[IFLA_IPTUN_FWMARK])
1997                 parms->fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1998 }
1999
2000 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev,
2001                            struct nlattr *tb[], struct nlattr *data[],
2002                            struct netlink_ext_ack *extack)
2003 {
2004         struct net *net = dev_net(dev);
2005         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2006         struct ip_tunnel_encap ipencap;
2007         struct ip6_tnl *nt, *t;
2008         int err;
2009
2010         nt = netdev_priv(dev);
2011
2012         if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
2013                 err = ip6_tnl_encap_setup(nt, &ipencap);
2014                 if (err < 0)
2015                         return err;
2016         }
2017
2018         ip6_tnl_netlink_parms(data, &nt->parms);
2019
2020         if (nt->parms.collect_md) {
2021                 if (rtnl_dereference(ip6n->collect_md_tun))
2022                         return -EEXIST;
2023         } else {
2024                 t = ip6_tnl_locate(net, &nt->parms, 0);
2025                 if (!IS_ERR(t))
2026                         return -EEXIST;
2027         }
2028
2029         err = ip6_tnl_create2(dev);
2030         if (!err && tb[IFLA_MTU])
2031                 ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
2032
2033         return err;
2034 }
2035
2036 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[],
2037                               struct nlattr *data[],
2038                               struct netlink_ext_ack *extack)
2039 {
2040         struct ip6_tnl *t = netdev_priv(dev);
2041         struct __ip6_tnl_parm p;
2042         struct net *net = t->net;
2043         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2044         struct ip_tunnel_encap ipencap;
2045
2046         if (dev == ip6n->fb_tnl_dev)
2047                 return -EINVAL;
2048
2049         if (ip_tunnel_netlink_encap_parms(data, &ipencap)) {
2050                 int err = ip6_tnl_encap_setup(t, &ipencap);
2051
2052                 if (err < 0)
2053                         return err;
2054         }
2055         ip6_tnl_netlink_parms(data, &p);
2056         if (p.collect_md)
2057                 return -EINVAL;
2058
2059         t = ip6_tnl_locate(net, &p, 0);
2060         if (!IS_ERR(t)) {
2061                 if (t->dev != dev)
2062                         return -EEXIST;
2063         } else
2064                 t = netdev_priv(dev);
2065
2066         ip6_tnl_update(t, &p);
2067         return 0;
2068 }
2069
2070 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head)
2071 {
2072         struct net *net = dev_net(dev);
2073         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2074
2075         if (dev != ip6n->fb_tnl_dev)
2076                 unregister_netdevice_queue(dev, head);
2077 }
2078
2079 static size_t ip6_tnl_get_size(const struct net_device *dev)
2080 {
2081         return
2082                 /* IFLA_IPTUN_LINK */
2083                 nla_total_size(4) +
2084                 /* IFLA_IPTUN_LOCAL */
2085                 nla_total_size(sizeof(struct in6_addr)) +
2086                 /* IFLA_IPTUN_REMOTE */
2087                 nla_total_size(sizeof(struct in6_addr)) +
2088                 /* IFLA_IPTUN_TTL */
2089                 nla_total_size(1) +
2090                 /* IFLA_IPTUN_ENCAP_LIMIT */
2091                 nla_total_size(1) +
2092                 /* IFLA_IPTUN_FLOWINFO */
2093                 nla_total_size(4) +
2094                 /* IFLA_IPTUN_FLAGS */
2095                 nla_total_size(4) +
2096                 /* IFLA_IPTUN_PROTO */
2097                 nla_total_size(1) +
2098                 /* IFLA_IPTUN_ENCAP_TYPE */
2099                 nla_total_size(2) +
2100                 /* IFLA_IPTUN_ENCAP_FLAGS */
2101                 nla_total_size(2) +
2102                 /* IFLA_IPTUN_ENCAP_SPORT */
2103                 nla_total_size(2) +
2104                 /* IFLA_IPTUN_ENCAP_DPORT */
2105                 nla_total_size(2) +
2106                 /* IFLA_IPTUN_COLLECT_METADATA */
2107                 nla_total_size(0) +
2108                 /* IFLA_IPTUN_FWMARK */
2109                 nla_total_size(4) +
2110                 0;
2111 }
2112
2113 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev)
2114 {
2115         struct ip6_tnl *tunnel = netdev_priv(dev);
2116         struct __ip6_tnl_parm *parm = &tunnel->parms;
2117
2118         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
2119             nla_put_in6_addr(skb, IFLA_IPTUN_LOCAL, &parm->laddr) ||
2120             nla_put_in6_addr(skb, IFLA_IPTUN_REMOTE, &parm->raddr) ||
2121             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) ||
2122             nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) ||
2123             nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) ||
2124             nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) ||
2125             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto) ||
2126             nla_put_u32(skb, IFLA_IPTUN_FWMARK, parm->fwmark))
2127                 goto nla_put_failure;
2128
2129         if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, tunnel->encap.type) ||
2130             nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, tunnel->encap.sport) ||
2131             nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, tunnel->encap.dport) ||
2132             nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, tunnel->encap.flags))
2133                 goto nla_put_failure;
2134
2135         if (parm->collect_md)
2136                 if (nla_put_flag(skb, IFLA_IPTUN_COLLECT_METADATA))
2137                         goto nla_put_failure;
2138
2139         return 0;
2140
2141 nla_put_failure:
2142         return -EMSGSIZE;
2143 }
2144
2145 struct net *ip6_tnl_get_link_net(const struct net_device *dev)
2146 {
2147         struct ip6_tnl *tunnel = netdev_priv(dev);
2148
2149         return READ_ONCE(tunnel->net);
2150 }
2151 EXPORT_SYMBOL(ip6_tnl_get_link_net);
2152
2153 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = {
2154         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
2155         [IFLA_IPTUN_LOCAL]              = { .len = sizeof(struct in6_addr) },
2156         [IFLA_IPTUN_REMOTE]             = { .len = sizeof(struct in6_addr) },
2157         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
2158         [IFLA_IPTUN_ENCAP_LIMIT]        = { .type = NLA_U8 },
2159         [IFLA_IPTUN_FLOWINFO]           = { .type = NLA_U32 },
2160         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U32 },
2161         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
2162         [IFLA_IPTUN_ENCAP_TYPE]         = { .type = NLA_U16 },
2163         [IFLA_IPTUN_ENCAP_FLAGS]        = { .type = NLA_U16 },
2164         [IFLA_IPTUN_ENCAP_SPORT]        = { .type = NLA_U16 },
2165         [IFLA_IPTUN_ENCAP_DPORT]        = { .type = NLA_U16 },
2166         [IFLA_IPTUN_COLLECT_METADATA]   = { .type = NLA_FLAG },
2167         [IFLA_IPTUN_FWMARK]             = { .type = NLA_U32 },
2168 };
2169
2170 static struct rtnl_link_ops ip6_link_ops __read_mostly = {
2171         .kind           = "ip6tnl",
2172         .maxtype        = IFLA_IPTUN_MAX,
2173         .policy         = ip6_tnl_policy,
2174         .priv_size      = sizeof(struct ip6_tnl),
2175         .setup          = ip6_tnl_dev_setup,
2176         .validate       = ip6_tnl_validate,
2177         .newlink        = ip6_tnl_newlink,
2178         .changelink     = ip6_tnl_changelink,
2179         .dellink        = ip6_tnl_dellink,
2180         .get_size       = ip6_tnl_get_size,
2181         .fill_info      = ip6_tnl_fill_info,
2182         .get_link_net   = ip6_tnl_get_link_net,
2183 };
2184
2185 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = {
2186         .handler        = ip4ip6_rcv,
2187         .err_handler    = ip4ip6_err,
2188         .priority       =       1,
2189 };
2190
2191 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = {
2192         .handler        = ip6ip6_rcv,
2193         .err_handler    = ip6ip6_err,
2194         .priority       =       1,
2195 };
2196
2197 static struct xfrm6_tunnel mplsip6_handler __read_mostly = {
2198         .handler        = mplsip6_rcv,
2199         .err_handler    = mplsip6_err,
2200         .priority       =       1,
2201 };
2202
2203 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net, struct list_head *list)
2204 {
2205         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2206         struct net_device *dev, *aux;
2207         int h;
2208         struct ip6_tnl *t;
2209
2210         for_each_netdev_safe(net, dev, aux)
2211                 if (dev->rtnl_link_ops == &ip6_link_ops)
2212                         unregister_netdevice_queue(dev, list);
2213
2214         for (h = 0; h < IP6_TUNNEL_HASH_SIZE; h++) {
2215                 t = rtnl_dereference(ip6n->tnls_r_l[h]);
2216                 while (t) {
2217                         /* If dev is in the same netns, it has already
2218                          * been added to the list by the previous loop.
2219                          */
2220                         if (!net_eq(dev_net(t->dev), net))
2221                                 unregister_netdevice_queue(t->dev, list);
2222                         t = rtnl_dereference(t->next);
2223                 }
2224         }
2225
2226         t = rtnl_dereference(ip6n->tnls_wc[0]);
2227         while (t) {
2228                 /* If dev is in the same netns, it has already
2229                  * been added to the list by the previous loop.
2230                  */
2231                 if (!net_eq(dev_net(t->dev), net))
2232                         unregister_netdevice_queue(t->dev, list);
2233                 t = rtnl_dereference(t->next);
2234         }
2235 }
2236
2237 static int __net_init ip6_tnl_init_net(struct net *net)
2238 {
2239         struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
2240         struct ip6_tnl *t = NULL;
2241         int err;
2242
2243         ip6n->tnls[0] = ip6n->tnls_wc;
2244         ip6n->tnls[1] = ip6n->tnls_r_l;
2245
2246         if (!net_has_fallback_tunnels(net))
2247                 return 0;
2248         err = -ENOMEM;
2249         ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
2250                                         NET_NAME_UNKNOWN, ip6_tnl_dev_setup);
2251
2252         if (!ip6n->fb_tnl_dev)
2253                 goto err_alloc_dev;
2254         dev_net_set(ip6n->fb_tnl_dev, net);
2255         ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops;
2256         /* FB netdevice is special: we have one, and only one per netns.
2257          * Allowing to move it to another netns is clearly unsafe.
2258          */
2259         ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL;
2260
2261         err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev);
2262         if (err < 0)
2263                 goto err_register;
2264
2265         err = register_netdev(ip6n->fb_tnl_dev);
2266         if (err < 0)
2267                 goto err_register;
2268
2269         t = netdev_priv(ip6n->fb_tnl_dev);
2270
2271         strcpy(t->parms.name, ip6n->fb_tnl_dev->name);
2272         return 0;
2273
2274 err_register:
2275         free_netdev(ip6n->fb_tnl_dev);
2276 err_alloc_dev:
2277         return err;
2278 }
2279
2280 static void __net_exit ip6_tnl_exit_batch_rtnl(struct list_head *net_list,
2281                                                struct list_head *dev_to_kill)
2282 {
2283         struct net *net;
2284
2285         ASSERT_RTNL();
2286         list_for_each_entry(net, net_list, exit_list)
2287                 ip6_tnl_destroy_tunnels(net, dev_to_kill);
2288 }
2289
2290 static struct pernet_operations ip6_tnl_net_ops = {
2291         .init = ip6_tnl_init_net,
2292         .exit_batch_rtnl = ip6_tnl_exit_batch_rtnl,
2293         .id   = &ip6_tnl_net_id,
2294         .size = sizeof(struct ip6_tnl_net),
2295 };
2296
2297 /**
2298  * ip6_tunnel_init - register protocol and reserve needed resources
2299  *
2300  * Return: 0 on success
2301  **/
2302
2303 static int __init ip6_tunnel_init(void)
2304 {
2305         int  err;
2306
2307         if (!ipv6_mod_enabled())
2308                 return -EOPNOTSUPP;
2309
2310         err = register_pernet_device(&ip6_tnl_net_ops);
2311         if (err < 0)
2312                 goto out_pernet;
2313
2314         err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET);
2315         if (err < 0) {
2316                 pr_err("%s: can't register ip4ip6\n", __func__);
2317                 goto out_ip4ip6;
2318         }
2319
2320         err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6);
2321         if (err < 0) {
2322                 pr_err("%s: can't register ip6ip6\n", __func__);
2323                 goto out_ip6ip6;
2324         }
2325
2326         if (ip6_tnl_mpls_supported()) {
2327                 err = xfrm6_tunnel_register(&mplsip6_handler, AF_MPLS);
2328                 if (err < 0) {
2329                         pr_err("%s: can't register mplsip6\n", __func__);
2330                         goto out_mplsip6;
2331                 }
2332         }
2333
2334         err = rtnl_link_register(&ip6_link_ops);
2335         if (err < 0)
2336                 goto rtnl_link_failed;
2337
2338         return 0;
2339
2340 rtnl_link_failed:
2341         if (ip6_tnl_mpls_supported())
2342                 xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS);
2343 out_mplsip6:
2344         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
2345 out_ip6ip6:
2346         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
2347 out_ip4ip6:
2348         unregister_pernet_device(&ip6_tnl_net_ops);
2349 out_pernet:
2350         return err;
2351 }
2352
2353 /**
2354  * ip6_tunnel_cleanup - free resources and unregister protocol
2355  **/
2356
2357 static void __exit ip6_tunnel_cleanup(void)
2358 {
2359         rtnl_link_unregister(&ip6_link_ops);
2360         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
2361                 pr_info("%s: can't deregister ip4ip6\n", __func__);
2362
2363         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
2364                 pr_info("%s: can't deregister ip6ip6\n", __func__);
2365
2366         if (ip6_tnl_mpls_supported() &&
2367             xfrm6_tunnel_deregister(&mplsip6_handler, AF_MPLS))
2368                 pr_info("%s: can't deregister mplsip6\n", __func__);
2369         unregister_pernet_device(&ip6_tnl_net_ops);
2370 }
2371
2372 module_init(ip6_tunnel_init);
2373 module_exit(ip6_tunnel_cleanup);