net/ipv6/sit.c

   1 /*
   2  *      IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *      Alexey Kuznetsov        <kuznet@ms2.inr.ac.ru>
   8  *
   9  *      This program is free software; you can redistribute it and/or
  10  *      modify it under the terms of the GNU General Public License
  11  *      as published by the Free Software Foundation; either version
  12  *      2 of the License, or (at your option) any later version.
  13  *
  14  *      Changes:
  15  * Roger Venning <r.venning@telstra.com>:       6to4 support
  16  * Nate Thompson <nate@thebog.net>:             6to4 support
  17  * Fred Templin <fred.l.templin@boeing.com>:    isatap support
  18  */
  19
  20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  21
  22 #include <linux/module.h>
  23 #include <linux/capability.h>
  24 #include <linux/errno.h>
  25 #include <linux/types.h>
  26 #include <linux/socket.h>
  27 #include <linux/sockios.h>
  28 #include <linux/net.h>
  29 #include <linux/in6.h>
  30 #include <linux/netdevice.h>
  31 #include <linux/if_arp.h>
  32 #include <linux/icmp.h>
  33 #include <linux/slab.h>
  34 #include <asm/uaccess.h>
  35 #include <linux/init.h>
  36 #include <linux/netfilter_ipv4.h>
  37 #include <linux/if_ether.h>
  38
  39 #include <net/sock.h>
  40 #include <net/snmp.h>
  41
  42 #include <net/ipv6.h>
  43 #include <net/protocol.h>
  44 #include <net/transp_v6.h>
  45 #include <net/ip6_fib.h>
  46 #include <net/ip6_route.h>
  47 #include <net/ndisc.h>
  48 #include <net/addrconf.h>
  49 #include <net/ip.h>
  50 #include <net/udp.h>
  51 #include <net/icmp.h>
  52 #include <net/ip_tunnels.h>
  53 #include <net/inet_ecn.h>
  54 #include <net/xfrm.h>
  55 #include <net/dsfield.h>
  56 #include <net/net_namespace.h>
  57 #include <net/netns/generic.h>
  58
  59 /*
  60    This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
  61
  62    For comments look at net/ipv4/ip_gre.c --ANK
  63  */
  64
  65 #define HASH_SIZE  16
  66 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
  67
  68 static bool log_ecn_error = true;
  69 module_param(log_ecn_error, bool, 0644);
  70 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  71
  72 static int ipip6_tunnel_init(struct net_device *dev);
  73 static void ipip6_tunnel_setup(struct net_device *dev);
  74 static void ipip6_dev_free(struct net_device *dev);
  75 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
  76                       __be32 *v4dst);
  77 static struct rtnl_link_ops sit_link_ops __read_mostly;
  78
  79 static int sit_net_id __read_mostly;
  80 struct sit_net {
  81         struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE];
  82         struct ip_tunnel __rcu *tunnels_r[HASH_SIZE];
  83         struct ip_tunnel __rcu *tunnels_l[HASH_SIZE];
  84         struct ip_tunnel __rcu *tunnels_wc[1];
  85         struct ip_tunnel __rcu **tunnels[4];
  86
  87         struct net_device *fb_tunnel_dev;
  88 };
  89
  90 /*
  91  * Must be invoked with rcu_read_lock
  92  */
  93 static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
  94                 struct net_device *dev, __be32 remote, __be32 local)
  95 {
  96         unsigned int h0 = HASH(remote);
  97         unsigned int h1 = HASH(local);
  98         struct ip_tunnel *t;
  99         struct sit_net *sitn = net_generic(net, sit_net_id);
 100
 101         for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
 102                 if (local == t->parms.iph.saddr &&
 103                     remote == t->parms.iph.daddr &&
 104                     (!dev || !t->parms.link || dev->ifindex == t->parms.link) &&
 105                     (t->dev->flags & IFF_UP))
 106                         return t;
 107         }
 108         for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) {
 109                 if (remote == t->parms.iph.daddr &&
 110                     (!dev || !t->parms.link || dev->ifindex == t->parms.link) &&
 111                     (t->dev->flags & IFF_UP))
 112                         return t;
 113         }
 114         for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
 115                 if (local == t->parms.iph.saddr &&
 116                     (!dev || !t->parms.link || dev->ifindex == t->parms.link) &&
 117                     (t->dev->flags & IFF_UP))
 118                         return t;
 119         }
 120         t = rcu_dereference(sitn->tunnels_wc[0]);
 121         if (t && (t->dev->flags & IFF_UP))
 122                 return t;
 123         return NULL;
 124 }
 125
 126 static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
 127                 struct ip_tunnel_parm *parms)
 128 {
 129         __be32 remote = parms->iph.daddr;
 130         __be32 local = parms->iph.saddr;
 131         unsigned int h = 0;
 132         int prio = 0;
 133
 134         if (remote) {
 135                 prio |= 2;
 136                 h ^= HASH(remote);
 137         }
 138         if (local) {
 139                 prio |= 1;
 140                 h ^= HASH(local);
 141         }
 142         return &sitn->tunnels[prio][h];
 143 }
 144
 145 static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
 146                 struct ip_tunnel *t)
 147 {
 148         return __ipip6_bucket(sitn, &t->parms);
 149 }
 150
 151 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
 152 {
 153         struct ip_tunnel __rcu **tp;
 154         struct ip_tunnel *iter;
 155
 156         for (tp = ipip6_bucket(sitn, t);
 157              (iter = rtnl_dereference(*tp)) != NULL;
 158              tp = &iter->next) {
 159                 if (t == iter) {
 160                         rcu_assign_pointer(*tp, t->next);
 161                         break;
 162                 }
 163         }
 164 }
 165
 166 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
 167 {
 168         struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
 169
 170         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 171         rcu_assign_pointer(*tp, t);
 172 }
 173
 174 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
 175 {
 176 #ifdef CONFIG_IPV6_SIT_6RD
 177         struct ip_tunnel *t = netdev_priv(dev);
 178
 179         if (t->dev == sitn->fb_tunnel_dev) {
 180                 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
 181                 t->ip6rd.relay_prefix = 0;
 182                 t->ip6rd.prefixlen = 16;
 183                 t->ip6rd.relay_prefixlen = 0;
 184         } else {
 185                 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
 186                 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
 187         }
 188 #endif
 189 }
 190
 191 static int ipip6_tunnel_create(struct net_device *dev)
 192 {
 193         struct ip_tunnel *t = netdev_priv(dev);
 194         struct net *net = dev_net(dev);
 195         struct sit_net *sitn = net_generic(net, sit_net_id);
 196         int err;
 197
 198         memcpy(dev->dev_addr, &t->parms.iph.saddr, 4);
 199         memcpy(dev->broadcast, &t->parms.iph.daddr, 4);
 200
 201         if ((__force u16)t->parms.i_flags & SIT_ISATAP)
 202                 dev->priv_flags |= IFF_ISATAP;
 203
 204         dev->rtnl_link_ops = &sit_link_ops;
 205
 206         err = register_netdevice(dev);
 207         if (err < 0)
 208                 goto out;
 209
 210         ipip6_tunnel_clone_6rd(dev, sitn);
 211
 212         dev_hold(dev);
 213
 214         ipip6_tunnel_link(sitn, t);
 215         return 0;
 216
 217 out:
 218         return err;
 219 }
 220
 221 static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
 222                 struct ip_tunnel_parm *parms, int create)
 223 {
 224         __be32 remote = parms->iph.daddr;
 225         __be32 local = parms->iph.saddr;
 226         struct ip_tunnel *t, *nt;
 227         struct ip_tunnel __rcu **tp;
 228         struct net_device *dev;
 229         char name[IFNAMSIZ];
 230         struct sit_net *sitn = net_generic(net, sit_net_id);
 231
 232         for (tp = __ipip6_bucket(sitn, parms);
 233             (t = rtnl_dereference(*tp)) != NULL;
 234              tp = &t->next) {
 235                 if (local == t->parms.iph.saddr &&
 236                     remote == t->parms.iph.daddr &&
 237                     parms->link == t->parms.link) {
 238                         if (create)
 239                                 return NULL;
 240                         else
 241                                 return t;
 242                 }
 243         }
 244         if (!create)
 245                 goto failed;
 246
 247         if (parms->name[0])
 248                 strlcpy(name, parms->name, IFNAMSIZ);
 249         else
 250                 strcpy(name, "sit%d");
 251
 252         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 253                            ipip6_tunnel_setup);
 254         if (!dev)
 255                 return NULL;
 256
 257         dev_net_set(dev, net);
 258
 259         nt = netdev_priv(dev);
 260
 261         nt->parms = *parms;
 262         if (ipip6_tunnel_create(dev) < 0)
 263                 goto failed_free;
 264
 265         return nt;
 266
 267 failed_free:
 268         ipip6_dev_free(dev);
 269 failed:
 270         return NULL;
 271 }
 272
 273 #define for_each_prl_rcu(start)                 \
 274         for (prl = rcu_dereference(start);      \
 275              prl;                               \
 276              prl = rcu_dereference(prl->next))
 277
 278 static struct ip_tunnel_prl_entry *
 279 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
 280 {
 281         struct ip_tunnel_prl_entry *prl;
 282
 283         for_each_prl_rcu(t->prl)
 284                 if (prl->addr == addr)
 285                         break;
 286         return prl;
 287
 288 }
 289
 290 static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
 291                                 struct ip_tunnel_prl __user *a)
 292 {
 293         struct ip_tunnel_prl kprl, *kp;
 294         struct ip_tunnel_prl_entry *prl;
 295         unsigned int cmax, c = 0, ca, len;
 296         int ret = 0;
 297
 298         if (copy_from_user(&kprl, a, sizeof(kprl)))
 299                 return -EFAULT;
 300         cmax = kprl.datalen / sizeof(kprl);
 301         if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
 302                 cmax = 1;
 303
 304         /* For simple GET or for root users,
 305          * we try harder to allocate.
 306          */
 307         kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
 308                 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
 309                 NULL;
 310
 311         rcu_read_lock();
 312
 313         ca = t->prl_count < cmax ? t->prl_count : cmax;
 314
 315         if (!kp) {
 316                 /* We don't try hard to allocate much memory for
 317                  * non-root users.
 318                  * For root users, retry allocating enough memory for
 319                  * the answer.
 320                  */
 321                 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
 322                 if (!kp) {
 323                         ret = -ENOMEM;
 324                         goto out;
 325                 }
 326         }
 327
 328         c = 0;
 329         for_each_prl_rcu(t->prl) {
 330                 if (c >= cmax)
 331                         break;
 332                 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
 333                         continue;
 334                 kp[c].addr = prl->addr;
 335                 kp[c].flags = prl->flags;
 336                 c++;
 337                 if (kprl.addr != htonl(INADDR_ANY))
 338                         break;
 339         }
 340 out:
 341         rcu_read_unlock();
 342
 343         len = sizeof(*kp) * c;
 344         ret = 0;
 345         if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
 346                 ret = -EFAULT;
 347
 348         kfree(kp);
 349
 350         return ret;
 351 }
 352
 353 static int
 354 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
 355 {
 356         struct ip_tunnel_prl_entry *p;
 357         int err = 0;
 358
 359         if (a->addr == htonl(INADDR_ANY))
 360                 return -EINVAL;
 361
 362         ASSERT_RTNL();
 363
 364         for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
 365                 if (p->addr == a->addr) {
 366                         if (chg) {
 367                                 p->flags = a->flags;
 368                                 goto out;
 369                         }
 370                         err = -EEXIST;
 371                         goto out;
 372                 }
 373         }
 374
 375         if (chg) {
 376                 err = -ENXIO;
 377                 goto out;
 378         }
 379
 380         p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
 381         if (!p) {
 382                 err = -ENOBUFS;
 383                 goto out;
 384         }
 385
 386         p->next = t->prl;
 387         p->addr = a->addr;
 388         p->flags = a->flags;
 389         t->prl_count++;
 390         rcu_assign_pointer(t->prl, p);
 391 out:
 392         return err;
 393 }
 394
 395 static void prl_list_destroy_rcu(struct rcu_head *head)
 396 {
 397         struct ip_tunnel_prl_entry *p, *n;
 398
 399         p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
 400         do {
 401                 n = rcu_dereference_protected(p->next, 1);
 402                 kfree(p);
 403                 p = n;
 404         } while (p);
 405 }
 406
 407 static int
 408 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
 409 {
 410         struct ip_tunnel_prl_entry *x;
 411         struct ip_tunnel_prl_entry __rcu **p;
 412         int err = 0;
 413
 414         ASSERT_RTNL();
 415
 416         if (a && a->addr != htonl(INADDR_ANY)) {
 417                 for (p = &t->prl;
 418                      (x = rtnl_dereference(*p)) != NULL;
 419                      p = &x->next) {
 420                         if (x->addr == a->addr) {
 421                                 *p = x->next;
 422                                 kfree_rcu(x, rcu_head);
 423                                 t->prl_count--;
 424                                 goto out;
 425                         }
 426                 }
 427                 err = -ENXIO;
 428         } else {
 429                 x = rtnl_dereference(t->prl);
 430                 if (x) {
 431                         t->prl_count = 0;
 432                         call_rcu(&x->rcu_head, prl_list_destroy_rcu);
 433                         t->prl = NULL;
 434                 }
 435         }
 436 out:
 437         return err;
 438 }
 439
 440 static int
 441 isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
 442 {
 443         struct ip_tunnel_prl_entry *p;
 444         int ok = 1;
 445
 446         rcu_read_lock();
 447         p = __ipip6_tunnel_locate_prl(t, iph->saddr);
 448         if (p) {
 449                 if (p->flags & PRL_DEFAULT)
 450                         skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
 451                 else
 452                         skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
 453         } else {
 454                 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
 455
 456                 if (ipv6_addr_is_isatap(addr6) &&
 457                     (addr6->s6_addr32[3] == iph->saddr) &&
 458                     ipv6_chk_prefix(addr6, t->dev))
 459                         skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
 460                 else
 461                         ok = 0;
 462         }
 463         rcu_read_unlock();
 464         return ok;
 465 }
 466
 467 static void ipip6_tunnel_uninit(struct net_device *dev)
 468 {
 469         struct ip_tunnel *tunnel = netdev_priv(dev);
 470         struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
 471
 472         if (dev == sitn->fb_tunnel_dev) {
 473                 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
 474         } else {
 475                 ipip6_tunnel_unlink(sitn, tunnel);
 476                 ipip6_tunnel_del_prl(tunnel, NULL);
 477         }
 478         dst_cache_reset(&tunnel->dst_cache);
 479         dev_put(dev);
 480 }
 481
 482 /* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
 483  * if sufficient data bytes are available
 484  */
 485 static int ipip6_err_gen_icmpv6_unreach(struct sk_buff *skb)
 486 {
 487         int ihl = ((const struct iphdr *)skb->data)->ihl*4;
 488         struct rt6_info *rt;
 489         struct sk_buff *skb2;
 490
 491         if (!pskb_may_pull(skb, ihl + sizeof(struct ipv6hdr) + 8))
 492                 return 1;
 493
 494         skb2 = skb_clone(skb, GFP_ATOMIC);
 495
 496         if (!skb2)
 497                 return 1;
 498
 499         skb_dst_drop(skb2);
 500         skb_pull(skb2, ihl);
 501         skb_reset_network_header(skb2);
 502
 503         rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0, 0);
 504
 505         if (rt && rt->dst.dev)
 506                 skb2->dev = rt->dst.dev;
 507
 508         icmpv6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
 509
 510         if (rt)
 511                 ip6_rt_put(rt);
 512
 513         kfree_skb(skb2);
 514
 515         return 0;
 516 }
 517
 518 static int ipip6_err(struct sk_buff *skb, u32 info)
 519 {
 520         const struct iphdr *iph = (const struct iphdr *)skb->data;
 521         const int type = icmp_hdr(skb)->type;
 522         const int code = icmp_hdr(skb)->code;
 523         struct ip_tunnel *t;
 524         int err;
 525
 526         switch (type) {
 527         default:
 528         case ICMP_PARAMETERPROB:
 529                 return 0;
 530
 531         case ICMP_DEST_UNREACH:
 532                 switch (code) {
 533                 case ICMP_SR_FAILED:
 534                         /* Impossible event. */
 535                         return 0;
 536                 default:
 537                         /* All others are translated to HOST_UNREACH.
 538                            rfc2003 contains "deep thoughts" about NET_UNREACH,
 539                            I believe they are just ether pollution. --ANK
 540                          */
 541                         break;
 542                 }
 543                 break;
 544         case ICMP_TIME_EXCEEDED:
 545                 if (code != ICMP_EXC_TTL)
 546                         return 0;
 547                 break;
 548         case ICMP_REDIRECT:
 549                 break;
 550         }
 551
 552         err = -ENOENT;
 553
 554         t = ipip6_tunnel_lookup(dev_net(skb->dev),
 555                                 skb->dev,
 556                                 iph->daddr,
 557                                 iph->saddr);
 558         if (!t)
 559                 goto out;
 560
 561         if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
 562                 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
 563                                  t->parms.link, 0, iph->protocol, 0);
 564                 err = 0;
 565                 goto out;
 566         }
 567         if (type == ICMP_REDIRECT) {
 568                 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
 569                               iph->protocol, 0);
 570                 err = 0;
 571                 goto out;
 572         }
 573
 574         if (t->parms.iph.daddr == 0)
 575                 goto out;
 576
 577         err = 0;
 578         if (!ipip6_err_gen_icmpv6_unreach(skb))
 579                 goto out;
 580
 581         if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
 582                 goto out;
 583
 584         if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
 585                 t->err_count++;
 586         else
 587                 t->err_count = 1;
 588         t->err_time = jiffies;
 589 out:
 590         return err;
 591 }
 592
 593 static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
 594                                   const struct in6_addr *v6addr)
 595 {
 596         __be32 v4embed = 0;
 597         if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
 598                 return true;
 599         return false;
 600 }
 601
 602 /* Checks if an address matches an address on the tunnel interface.
 603  * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
 604  * Long story:
 605  * This function is called after we considered the packet as spoofed
 606  * in is_spoofed_6rd.
 607  * We may have a router that is doing NAT for proto 41 packets
 608  * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
 609  * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
 610  * function will return true, dropping the packet.
 611  * But, we can still check if is spoofed against the IP
 612  * addresses associated with the interface.
 613  */
 614 static bool only_dnatted(const struct ip_tunnel *tunnel,
 615         const struct in6_addr *v6dst)
 616 {
 617         int prefix_len;
 618
 619 #ifdef CONFIG_IPV6_SIT_6RD
 620         prefix_len = tunnel->ip6rd.prefixlen + 32
 621                 - tunnel->ip6rd.relay_prefixlen;
 622 #else
 623         prefix_len = 48;
 624 #endif
 625         return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
 626 }
 627
 628 /* Returns true if a packet is spoofed */
 629 static bool packet_is_spoofed(struct sk_buff *skb,
 630                               const struct iphdr *iph,
 631                               struct ip_tunnel *tunnel)
 632 {
 633         const struct ipv6hdr *ipv6h;
 634
 635         if (tunnel->dev->priv_flags & IFF_ISATAP) {
 636                 if (!isatap_chksrc(skb, iph, tunnel))
 637                         return true;
 638
 639                 return false;
 640         }
 641
 642         if (tunnel->dev->flags & IFF_POINTOPOINT)
 643                 return false;
 644
 645         ipv6h = ipv6_hdr(skb);
 646
 647         if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
 648                 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
 649                                      &iph->saddr, &ipv6h->saddr,
 650                                      &iph->daddr, &ipv6h->daddr);
 651                 return true;
 652         }
 653
 654         if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
 655                 return false;
 656
 657         if (only_dnatted(tunnel, &ipv6h->daddr))
 658                 return false;
 659
 660         net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
 661                              &iph->saddr, &ipv6h->saddr,
 662                              &iph->daddr, &ipv6h->daddr);
 663         return true;
 664 }
 665
 666 static int ipip6_rcv(struct sk_buff *skb)
 667 {
 668         const struct iphdr *iph = ip_hdr(skb);
 669         struct ip_tunnel *tunnel;
 670         int err;
 671
 672         tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 673                                      iph->saddr, iph->daddr);
 674         if (tunnel) {
 675                 struct pcpu_sw_netstats *tstats;
 676
 677                 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
 678                     tunnel->parms.iph.protocol != 0)
 679                         goto out;
 680
 681                 skb->mac_header = skb->network_header;
 682                 skb_reset_network_header(skb);
 683                 IPCB(skb)->flags = 0;
 684                 skb->dev = tunnel->dev;
 685
 686                 if (packet_is_spoofed(skb, iph, tunnel)) {
 687                         tunnel->dev->stats.rx_errors++;
 688                         goto out;
 689                 }
 690
 691                 if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
 692                     !net_eq(tunnel->net, dev_net(tunnel->dev))))
 693                         goto out;
 694
 695                 err = IP_ECN_decapsulate(iph, skb);
 696                 if (unlikely(err)) {
 697                         if (log_ecn_error)
 698                                 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
 699                                                      &iph->saddr, iph->tos);
 700                         if (err > 1) {
 701                                 ++tunnel->dev->stats.rx_frame_errors;
 702                                 ++tunnel->dev->stats.rx_errors;
 703                                 goto out;
 704                         }
 705                 }
 706
 707                 tstats = this_cpu_ptr(tunnel->dev->tstats);
 708                 u64_stats_update_begin(&tstats->syncp);
 709                 tstats->rx_packets++;
 710                 tstats->rx_bytes += skb->len;
 711                 u64_stats_update_end(&tstats->syncp);
 712
 713                 netif_rx(skb);
 714
 715                 return 0;
 716         }
 717
 718         /* no tunnel matched,  let upstream know, ipsec may handle it */
 719         return 1;
 720 out:
 721         kfree_skb(skb);
 722         return 0;
 723 }
 724
 725 static const struct tnl_ptk_info tpi = {
 726         /* no tunnel info required for ipip. */
 727         .proto = htons(ETH_P_IP),
 728 };
 729
 730 static int ipip_rcv(struct sk_buff *skb)
 731 {
 732         const struct iphdr *iph;
 733         struct ip_tunnel *tunnel;
 734
 735         iph = ip_hdr(skb);
 736         tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 737                                      iph->saddr, iph->daddr);
 738         if (tunnel) {
 739                 if (tunnel->parms.iph.protocol != IPPROTO_IPIP &&
 740                     tunnel->parms.iph.protocol != 0)
 741                         goto drop;
 742
 743                 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
 744                         goto drop;
 745                 if (iptunnel_pull_header(skb, 0, tpi.proto, false))
 746                         goto drop;
 747                 return ip_tunnel_rcv(tunnel, skb, &tpi, NULL, log_ecn_error);
 748         }
 749
 750         return 1;
 751
 752 drop:
 753         kfree_skb(skb);
 754         return 0;
 755 }
 756
 757 /*
 758  * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
 759  * stores the embedded IPv4 address in v4dst and returns true.
 760  */
 761 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
 762                       __be32 *v4dst)
 763 {
 764 #ifdef CONFIG_IPV6_SIT_6RD
 765         if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
 766                               tunnel->ip6rd.prefixlen)) {
 767                 unsigned int pbw0, pbi0;
 768                 int pbi1;
 769                 u32 d;
 770
 771                 pbw0 = tunnel->ip6rd.prefixlen >> 5;
 772                 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
 773
 774                 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
 775                     tunnel->ip6rd.relay_prefixlen;
 776
 777                 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
 778                 if (pbi1 > 0)
 779                         d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
 780                              (32 - pbi1);
 781
 782                 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
 783                 return true;
 784         }
 785 #else
 786         if (v6dst->s6_addr16[0] == htons(0x2002)) {
 787                 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
 788                 memcpy(v4dst, &v6dst->s6_addr16[1], 4);
 789                 return true;
 790         }
 791 #endif
 792         return false;
 793 }
 794
 795 static inline __be32 try_6rd(struct ip_tunnel *tunnel,
 796                              const struct in6_addr *v6dst)
 797 {
 798         __be32 dst = 0;
 799         check_6rd(tunnel, v6dst, &dst);
 800         return dst;
 801 }
 802
 803 /*
 804  *      This function assumes it is being called from dev_queue_xmit()
 805  *      and that skb is filled properly by that function.
 806  */
 807
 808 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 809                                      struct net_device *dev)
 810 {
 811         struct ip_tunnel *tunnel = netdev_priv(dev);
 812         const struct iphdr  *tiph = &tunnel->parms.iph;
 813         const struct ipv6hdr *iph6 = ipv6_hdr(skb);
 814         u8     tos = tunnel->parms.iph.tos;
 815         __be16 df = tiph->frag_off;
 816         struct rtable *rt;              /* Route to the other host */
 817         struct net_device *tdev;        /* Device to other host */
 818         unsigned int max_headroom;      /* The extra header space needed */
 819         __be32 dst = tiph->daddr;
 820         struct flowi4 fl4;
 821         int    mtu;
 822         const struct in6_addr *addr6;
 823         int addr_type;
 824         u8 ttl;
 825         u8 protocol = IPPROTO_IPV6;
 826         int t_hlen = tunnel->hlen + sizeof(struct iphdr);
 827
 828         if (skb->protocol != htons(ETH_P_IPV6))
 829                 goto tx_error;
 830
 831         if (tos == 1)
 832                 tos = ipv6_get_dsfield(iph6);
 833
 834         /* ISATAP (RFC4214) - must come before 6to4 */
 835         if (dev->priv_flags & IFF_ISATAP) {
 836                 struct neighbour *neigh = NULL;
 837                 bool do_tx_error = false;
 838
 839                 if (skb_dst(skb))
 840                         neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 841
 842                 if (!neigh) {
 843                         net_dbg_ratelimited("nexthop == NULL\n");
 844                         goto tx_error;
 845                 }
 846
 847                 addr6 = (const struct in6_addr *)&neigh->primary_key;
 848                 addr_type = ipv6_addr_type(addr6);
 849
 850                 if ((addr_type & IPV6_ADDR_UNICAST) &&
 851                      ipv6_addr_is_isatap(addr6))
 852                         dst = addr6->s6_addr32[3];
 853                 else
 854                         do_tx_error = true;
 855
 856                 neigh_release(neigh);
 857                 if (do_tx_error)
 858                         goto tx_error;
 859         }
 860
 861         if (!dst)
 862                 dst = try_6rd(tunnel, &iph6->daddr);
 863
 864         if (!dst) {
 865                 struct neighbour *neigh = NULL;
 866                 bool do_tx_error = false;
 867
 868                 if (skb_dst(skb))
 869                         neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 870
 871                 if (!neigh) {
 872                         net_dbg_ratelimited("nexthop == NULL\n");
 873                         goto tx_error;
 874                 }
 875
 876                 addr6 = (const struct in6_addr *)&neigh->primary_key;
 877                 addr_type = ipv6_addr_type(addr6);
 878
 879                 if (addr_type == IPV6_ADDR_ANY) {
 880                         addr6 = &ipv6_hdr(skb)->daddr;
 881                         addr_type = ipv6_addr_type(addr6);
 882                 }
 883
 884                 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
 885                         dst = addr6->s6_addr32[3];
 886                 else
 887                         do_tx_error = true;
 888
 889                 neigh_release(neigh);
 890                 if (do_tx_error)
 891                         goto tx_error;
 892         }
 893
 894         rt = ip_route_output_ports(tunnel->net, &fl4, NULL,
 895                                    dst, tiph->saddr,
 896                                    0, 0,
 897                                    IPPROTO_IPV6, RT_TOS(tos),
 898                                    tunnel->parms.link);
 899         if (IS_ERR(rt)) {
 900                 dev->stats.tx_carrier_errors++;
 901                 goto tx_error_icmp;
 902         }
 903         if (rt->rt_type != RTN_UNICAST) {
 904                 ip_rt_put(rt);
 905                 dev->stats.tx_carrier_errors++;
 906                 goto tx_error_icmp;
 907         }
 908         tdev = rt->dst.dev;
 909
 910         if (tdev == dev) {
 911                 ip_rt_put(rt);
 912                 dev->stats.collisions++;
 913                 goto tx_error;
 914         }
 915
 916         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) {
 917                 ip_rt_put(rt);
 918                 goto tx_error;
 919         }
 920
 921         if (df) {
 922                 mtu = dst_mtu(&rt->dst) - t_hlen;
 923
 924                 if (mtu < 68) {
 925                         dev->stats.collisions++;
 926                         ip_rt_put(rt);
 927                         goto tx_error;
 928                 }
 929
 930                 if (mtu < IPV6_MIN_MTU) {
 931                         mtu = IPV6_MIN_MTU;
 932                         df = 0;
 933                 }
 934
 935                 if (tunnel->parms.iph.daddr && skb_dst(skb))
 936                         skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 937
 938                 if (skb->len > mtu && !skb_is_gso(skb)) {
 939                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 940                         ip_rt_put(rt);
 941                         goto tx_error;
 942                 }
 943         }
 944
 945         if (tunnel->err_count > 0) {
 946                 if (time_before(jiffies,
 947                                 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
 948                         tunnel->err_count--;
 949                         dst_link_failure(skb);
 950                 } else
 951                         tunnel->err_count = 0;
 952         }
 953
 954         /*
 955          * Okay, now see if we can stuff it in the buffer as-is.
 956          */
 957         max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
 958
 959         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 960             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 961                 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
 962                 if (!new_skb) {
 963                         ip_rt_put(rt);
 964                         dev->stats.tx_dropped++;
 965                         kfree_skb(skb);
 966                         return NETDEV_TX_OK;
 967                 }
 968                 if (skb->sk)
 969                         skb_set_owner_w(new_skb, skb->sk);
 970                 dev_kfree_skb(skb);
 971                 skb = new_skb;
 972                 iph6 = ipv6_hdr(skb);
 973         }
 974         ttl = tiph->ttl;
 975         if (ttl == 0)
 976                 ttl = iph6->hop_limit;
 977         tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
 978
 979         if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) {
 980                 ip_rt_put(rt);
 981                 goto tx_error;
 982         }
 983
 984         skb_set_inner_ipproto(skb, IPPROTO_IPV6);
 985
 986         iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
 987                       df, !net_eq(tunnel->net, dev_net(dev)));
 988         return NETDEV_TX_OK;
 989
 990 tx_error_icmp:
 991         dst_link_failure(skb);
 992 tx_error:
 993         kfree_skb(skb);
 994         dev->stats.tx_errors++;
 995         return NETDEV_TX_OK;
 996 }
 997
 998 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 999 {
1000         struct ip_tunnel *tunnel = netdev_priv(dev);
1001         const struct iphdr  *tiph = &tunnel->parms.iph;
1002
1003         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
1004                 goto tx_error;
1005
1006         skb_set_inner_ipproto(skb, IPPROTO_IPIP);
1007
1008         ip_tunnel_xmit(skb, dev, tiph, IPPROTO_IPIP);
1009         return NETDEV_TX_OK;
1010 tx_error:
1011         kfree_skb(skb);
1012         dev->stats.tx_errors++;
1013         return NETDEV_TX_OK;
1014 }
1015
1016 static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1017                                    struct net_device *dev)
1018 {
1019         switch (skb->protocol) {
1020         case htons(ETH_P_IP):
1021                 ipip_tunnel_xmit(skb, dev);
1022                 break;
1023         case htons(ETH_P_IPV6):
1024                 ipip6_tunnel_xmit(skb, dev);
1025                 break;
1026         default:
1027                 goto tx_err;
1028         }
1029
1030         return NETDEV_TX_OK;
1031
1032 tx_err:
1033         dev->stats.tx_errors++;
1034         kfree_skb(skb);
1035         return NETDEV_TX_OK;
1036
1037 }
1038
1039 static void ipip6_tunnel_bind_dev(struct net_device *dev)
1040 {
1041         struct net_device *tdev = NULL;
1042         struct ip_tunnel *tunnel;
1043         const struct iphdr *iph;
1044         struct flowi4 fl4;
1045
1046         tunnel = netdev_priv(dev);
1047         iph = &tunnel->parms.iph;
1048
1049         if (iph->daddr) {
1050                 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1051                                                           NULL,
1052                                                           iph->daddr, iph->saddr,
1053                                                           0, 0,
1054                                                           IPPROTO_IPV6,
1055                                                           RT_TOS(iph->tos),
1056                                                           tunnel->parms.link);
1057
1058                 if (!IS_ERR(rt)) {
1059                         tdev = rt->dst.dev;
1060                         ip_rt_put(rt);
1061                 }
1062                 dev->flags |= IFF_POINTOPOINT;
1063         }
1064
1065         if (!tdev && tunnel->parms.link)
1066                 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1067
1068         if (tdev) {
1069                 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1070
1071                 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
1072                 dev->mtu = tdev->mtu - t_hlen;
1073                 if (dev->mtu < IPV6_MIN_MTU)
1074                         dev->mtu = IPV6_MIN_MTU;
1075         }
1076 }
1077
1078 static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p)
1079 {
1080         struct net *net = t->net;
1081         struct sit_net *sitn = net_generic(net, sit_net_id);
1082
1083         ipip6_tunnel_unlink(sitn, t);
1084         synchronize_net();
1085         t->parms.iph.saddr = p->iph.saddr;
1086         t->parms.iph.daddr = p->iph.daddr;
1087         memcpy(t->dev->dev_addr, &p->iph.saddr, 4);
1088         memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1089         ipip6_tunnel_link(sitn, t);
1090         t->parms.iph.ttl = p->iph.ttl;
1091         t->parms.iph.tos = p->iph.tos;
1092         if (t->parms.link != p->link) {
1093                 t->parms.link = p->link;
1094                 ipip6_tunnel_bind_dev(t->dev);
1095         }
1096         dst_cache_reset(&t->dst_cache);
1097         netdev_state_change(t->dev);
1098 }
1099
1100 #ifdef CONFIG_IPV6_SIT_6RD
1101 static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1102                                    struct ip_tunnel_6rd *ip6rd)
1103 {
1104         struct in6_addr prefix;
1105         __be32 relay_prefix;
1106
1107         if (ip6rd->relay_prefixlen > 32 ||
1108             ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1109                 return -EINVAL;
1110
1111         ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1112         if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1113                 return -EINVAL;
1114         if (ip6rd->relay_prefixlen)
1115                 relay_prefix = ip6rd->relay_prefix &
1116                                htonl(0xffffffffUL <<
1117                                      (32 - ip6rd->relay_prefixlen));
1118         else
1119                 relay_prefix = 0;
1120         if (relay_prefix != ip6rd->relay_prefix)
1121                 return -EINVAL;
1122
1123         t->ip6rd.prefix = prefix;
1124         t->ip6rd.relay_prefix = relay_prefix;
1125         t->ip6rd.prefixlen = ip6rd->prefixlen;
1126         t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1127         dst_cache_reset(&t->dst_cache);
1128         netdev_state_change(t->dev);
1129         return 0;
1130 }
1131 #endif
1132
1133 static int
1134 ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1135 {
1136         int err = 0;
1137         struct ip_tunnel_parm p;
1138         struct ip_tunnel_prl prl;
1139         struct ip_tunnel *t = netdev_priv(dev);
1140         struct net *net = t->net;
1141         struct sit_net *sitn = net_generic(net, sit_net_id);
1142 #ifdef CONFIG_IPV6_SIT_6RD
1143         struct ip_tunnel_6rd ip6rd;
1144 #endif
1145
1146         switch (cmd) {
1147         case SIOCGETTUNNEL:
1148 #ifdef CONFIG_IPV6_SIT_6RD
1149         case SIOCGET6RD:
1150 #endif
1151                 if (dev == sitn->fb_tunnel_dev) {
1152                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1153                                 err = -EFAULT;
1154                                 break;
1155                         }
1156                         t = ipip6_tunnel_locate(net, &p, 0);
1157                         if (!t)
1158                                 t = netdev_priv(dev);
1159                 }
1160
1161                 err = -EFAULT;
1162                 if (cmd == SIOCGETTUNNEL) {
1163                         memcpy(&p, &t->parms, sizeof(p));
1164                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
1165                                          sizeof(p)))
1166                                 goto done;
1167 #ifdef CONFIG_IPV6_SIT_6RD
1168                 } else {
1169                         ip6rd.prefix = t->ip6rd.prefix;
1170                         ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1171                         ip6rd.prefixlen = t->ip6rd.prefixlen;
1172                         ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1173                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
1174                                          sizeof(ip6rd)))
1175                                 goto done;
1176 #endif
1177                 }
1178                 err = 0;
1179                 break;
1180
1181         case SIOCADDTUNNEL:
1182         case SIOCCHGTUNNEL:
1183                 err = -EPERM;
1184                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1185                         goto done;
1186
1187                 err = -EFAULT;
1188                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1189                         goto done;
1190
1191                 err = -EINVAL;
1192                 if (p.iph.protocol != IPPROTO_IPV6 &&
1193                     p.iph.protocol != IPPROTO_IPIP &&
1194                     p.iph.protocol != 0)
1195                         goto done;
1196                 if (p.iph.version != 4 ||
1197                     p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
1198                         goto done;
1199                 if (p.iph.ttl)
1200                         p.iph.frag_off |= htons(IP_DF);
1201
1202                 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1203
1204                 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1205                         if (t) {
1206                                 if (t->dev != dev) {
1207                                         err = -EEXIST;
1208                                         break;
1209                                 }
1210                         } else {
1211                                 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
1212                                     (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
1213                                         err = -EINVAL;
1214                                         break;
1215                                 }
1216                                 t = netdev_priv(dev);
1217                         }
1218
1219                         ipip6_tunnel_update(t, &p);
1220                 }
1221
1222                 if (t) {
1223                         err = 0;
1224                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1225                                 err = -EFAULT;
1226                 } else
1227                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1228                 break;
1229
1230         case SIOCDELTUNNEL:
1231                 err = -EPERM;
1232                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1233                         goto done;
1234
1235                 if (dev == sitn->fb_tunnel_dev) {
1236                         err = -EFAULT;
1237                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1238                                 goto done;
1239                         err = -ENOENT;
1240                         t = ipip6_tunnel_locate(net, &p, 0);
1241                         if (!t)
1242                                 goto done;
1243                         err = -EPERM;
1244                         if (t == netdev_priv(sitn->fb_tunnel_dev))
1245                                 goto done;
1246                         dev = t->dev;
1247                 }
1248                 unregister_netdevice(dev);
1249                 err = 0;
1250                 break;
1251
1252         case SIOCGETPRL:
1253                 err = -EINVAL;
1254                 if (dev == sitn->fb_tunnel_dev)
1255                         goto done;
1256                 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1257                 break;
1258
1259         case SIOCADDPRL:
1260         case SIOCDELPRL:
1261         case SIOCCHGPRL:
1262                 err = -EPERM;
1263                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1264                         goto done;
1265                 err = -EINVAL;
1266                 if (dev == sitn->fb_tunnel_dev)
1267                         goto done;
1268                 err = -EFAULT;
1269                 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1270                         goto done;
1271
1272                 switch (cmd) {
1273                 case SIOCDELPRL:
1274                         err = ipip6_tunnel_del_prl(t, &prl);
1275                         break;
1276                 case SIOCADDPRL:
1277                 case SIOCCHGPRL:
1278                         err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1279                         break;
1280                 }
1281                 dst_cache_reset(&t->dst_cache);
1282                 netdev_state_change(dev);
1283                 break;
1284
1285 #ifdef CONFIG_IPV6_SIT_6RD
1286         case SIOCADD6RD:
1287         case SIOCCHG6RD:
1288         case SIOCDEL6RD:
1289                 err = -EPERM;
1290                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1291                         goto done;
1292
1293                 err = -EFAULT;
1294                 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1295                                    sizeof(ip6rd)))
1296                         goto done;
1297
1298                 if (cmd != SIOCDEL6RD) {
1299                         err = ipip6_tunnel_update_6rd(t, &ip6rd);
1300                         if (err < 0)
1301                                 goto done;
1302                 } else
1303                         ipip6_tunnel_clone_6rd(dev, sitn);
1304
1305                 err = 0;
1306                 break;
1307 #endif
1308
1309         default:
1310                 err = -EINVAL;
1311         }
1312
1313 done:
1314         return err;
1315 }
1316
1317 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1318 {
1319         struct ip_tunnel *tunnel = netdev_priv(dev);
1320         int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1321
1322         if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - t_hlen)
1323                 return -EINVAL;
1324         dev->mtu = new_mtu;
1325         return 0;
1326 }
1327
1328 static const struct net_device_ops ipip6_netdev_ops = {
1329         .ndo_init       = ipip6_tunnel_init,
1330         .ndo_uninit     = ipip6_tunnel_uninit,
1331         .ndo_start_xmit = sit_tunnel_xmit,
1332         .ndo_do_ioctl   = ipip6_tunnel_ioctl,
1333         .ndo_change_mtu = ipip6_tunnel_change_mtu,
1334         .ndo_get_stats64 = ip_tunnel_get_stats64,
1335         .ndo_get_iflink = ip_tunnel_get_iflink,
1336 };
1337
1338 static void ipip6_dev_free(struct net_device *dev)
1339 {
1340         struct ip_tunnel *tunnel = netdev_priv(dev);
1341
1342         dst_cache_destroy(&tunnel->dst_cache);
1343         free_percpu(dev->tstats);
1344         free_netdev(dev);
1345 }
1346
1347 #define SIT_FEATURES (NETIF_F_SG           | \
1348                       NETIF_F_FRAGLIST     | \
1349                       NETIF_F_HIGHDMA      | \
1350                       NETIF_F_GSO_SOFTWARE | \
1351                       NETIF_F_HW_CSUM)
1352
1353 static void ipip6_tunnel_setup(struct net_device *dev)
1354 {
1355         struct ip_tunnel *tunnel = netdev_priv(dev);
1356         int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1357
1358         dev->netdev_ops         = &ipip6_netdev_ops;
1359         dev->destructor         = ipip6_dev_free;
1360
1361         dev->type               = ARPHRD_SIT;
1362         dev->hard_header_len    = LL_MAX_HEADER + t_hlen;
1363         dev->mtu                = ETH_DATA_LEN - t_hlen;
1364         dev->flags              = IFF_NOARP;
1365         netif_keep_dst(dev);
1366         dev->addr_len           = 4;
1367         dev->features           |= NETIF_F_LLTX;
1368         dev->features           |= SIT_FEATURES;
1369         dev->hw_features        |= SIT_FEATURES;
1370 }
1371
1372 static int ipip6_tunnel_init(struct net_device *dev)
1373 {
1374         struct ip_tunnel *tunnel = netdev_priv(dev);
1375         int err;
1376
1377         tunnel->dev = dev;
1378         tunnel->net = dev_net(dev);
1379         strcpy(tunnel->parms.name, dev->name);
1380
1381         ipip6_tunnel_bind_dev(dev);
1382         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1383         if (!dev->tstats)
1384                 return -ENOMEM;
1385
1386         err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1387         if (err) {
1388                 free_percpu(dev->tstats);
1389                 return err;
1390         }
1391
1392         return 0;
1393 }
1394
1395 static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1396 {
1397         struct ip_tunnel *tunnel = netdev_priv(dev);
1398         struct iphdr *iph = &tunnel->parms.iph;
1399         struct net *net = dev_net(dev);
1400         struct sit_net *sitn = net_generic(net, sit_net_id);
1401
1402         iph->version            = 4;
1403         iph->protocol           = IPPROTO_IPV6;
1404         iph->ihl                = 5;
1405         iph->ttl                = 64;
1406
1407         dev_hold(dev);
1408         rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1409 }
1410
1411 static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[])
1412 {
1413         u8 proto;
1414
1415         if (!data || !data[IFLA_IPTUN_PROTO])
1416                 return 0;
1417
1418         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1419         if (proto != IPPROTO_IPV6 &&
1420             proto != IPPROTO_IPIP &&
1421             proto != 0)
1422                 return -EINVAL;
1423
1424         return 0;
1425 }
1426
1427 static void ipip6_netlink_parms(struct nlattr *data[],
1428                                 struct ip_tunnel_parm *parms)
1429 {
1430         memset(parms, 0, sizeof(*parms));
1431
1432         parms->iph.version = 4;
1433         parms->iph.protocol = IPPROTO_IPV6;
1434         parms->iph.ihl = 5;
1435         parms->iph.ttl = 64;
1436
1437         if (!data)
1438                 return;
1439
1440         if (data[IFLA_IPTUN_LINK])
1441                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1442
1443         if (data[IFLA_IPTUN_LOCAL])
1444                 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1445
1446         if (data[IFLA_IPTUN_REMOTE])
1447                 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1448
1449         if (data[IFLA_IPTUN_TTL]) {
1450                 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1451                 if (parms->iph.ttl)
1452                         parms->iph.frag_off = htons(IP_DF);
1453         }
1454
1455         if (data[IFLA_IPTUN_TOS])
1456                 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1457
1458         if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1459                 parms->iph.frag_off = htons(IP_DF);
1460
1461         if (data[IFLA_IPTUN_FLAGS])
1462                 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1463
1464         if (data[IFLA_IPTUN_PROTO])
1465                 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1466
1467 }
1468
1469 /* This function returns true when ENCAP attributes are present in the nl msg */
1470 static bool ipip6_netlink_encap_parms(struct nlattr *data[],
1471                                       struct ip_tunnel_encap *ipencap)
1472 {
1473         bool ret = false;
1474
1475         memset(ipencap, 0, sizeof(*ipencap));
1476
1477         if (!data)
1478                 return ret;
1479
1480         if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1481                 ret = true;
1482                 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1483         }
1484
1485         if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1486                 ret = true;
1487                 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1488         }
1489
1490         if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1491                 ret = true;
1492                 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1493         }
1494
1495         if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1496                 ret = true;
1497                 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1498         }
1499
1500         return ret;
1501 }
1502
1503 #ifdef CONFIG_IPV6_SIT_6RD
1504 /* This function returns true when 6RD attributes are present in the nl msg */
1505 static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1506                                     struct ip_tunnel_6rd *ip6rd)
1507 {
1508         bool ret = false;
1509         memset(ip6rd, 0, sizeof(*ip6rd));
1510
1511         if (!data)
1512                 return ret;
1513
1514         if (data[IFLA_IPTUN_6RD_PREFIX]) {
1515                 ret = true;
1516                 ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]);
1517         }
1518
1519         if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1520                 ret = true;
1521                 ip6rd->relay_prefix =
1522                         nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1523         }
1524
1525         if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1526                 ret = true;
1527                 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1528         }
1529
1530         if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1531                 ret = true;
1532                 ip6rd->relay_prefixlen =
1533                         nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1534         }
1535
1536         return ret;
1537 }
1538 #endif
1539
1540 static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1541                          struct nlattr *tb[], struct nlattr *data[])
1542 {
1543         struct net *net = dev_net(dev);
1544         struct ip_tunnel *nt;
1545         struct ip_tunnel_encap ipencap;
1546 #ifdef CONFIG_IPV6_SIT_6RD
1547         struct ip_tunnel_6rd ip6rd;
1548 #endif
1549         int err;
1550
1551         nt = netdev_priv(dev);
1552
1553         if (ipip6_netlink_encap_parms(data, &ipencap)) {
1554                 err = ip_tunnel_encap_setup(nt, &ipencap);
1555                 if (err < 0)
1556                         return err;
1557         }
1558
1559         ipip6_netlink_parms(data, &nt->parms);
1560
1561         if (ipip6_tunnel_locate(net, &nt->parms, 0))
1562                 return -EEXIST;
1563
1564         err = ipip6_tunnel_create(dev);
1565         if (err < 0)
1566                 return err;
1567
1568 #ifdef CONFIG_IPV6_SIT_6RD
1569         if (ipip6_netlink_6rd_parms(data, &ip6rd))
1570                 err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1571 #endif
1572
1573         return err;
1574 }
1575
1576 static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1577                           struct nlattr *data[])
1578 {
1579         struct ip_tunnel *t = netdev_priv(dev);
1580         struct ip_tunnel_parm p;
1581         struct ip_tunnel_encap ipencap;
1582         struct net *net = t->net;
1583         struct sit_net *sitn = net_generic(net, sit_net_id);
1584 #ifdef CONFIG_IPV6_SIT_6RD
1585         struct ip_tunnel_6rd ip6rd;
1586 #endif
1587         int err;
1588
1589         if (dev == sitn->fb_tunnel_dev)
1590                 return -EINVAL;
1591
1592         if (ipip6_netlink_encap_parms(data, &ipencap)) {
1593                 err = ip_tunnel_encap_setup(t, &ipencap);
1594                 if (err < 0)
1595                         return err;
1596         }
1597
1598         ipip6_netlink_parms(data, &p);
1599
1600         if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1601             (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1602                 return -EINVAL;
1603
1604         t = ipip6_tunnel_locate(net, &p, 0);
1605
1606         if (t) {
1607                 if (t->dev != dev)
1608                         return -EEXIST;
1609         } else
1610                 t = netdev_priv(dev);
1611
1612         ipip6_tunnel_update(t, &p);
1613
1614 #ifdef CONFIG_IPV6_SIT_6RD
1615         if (ipip6_netlink_6rd_parms(data, &ip6rd))
1616                 return ipip6_tunnel_update_6rd(t, &ip6rd);
1617 #endif
1618
1619         return 0;
1620 }
1621
1622 static size_t ipip6_get_size(const struct net_device *dev)
1623 {
1624         return
1625                 /* IFLA_IPTUN_LINK */
1626                 nla_total_size(4) +
1627                 /* IFLA_IPTUN_LOCAL */
1628                 nla_total_size(4) +
1629                 /* IFLA_IPTUN_REMOTE */
1630                 nla_total_size(4) +
1631                 /* IFLA_IPTUN_TTL */
1632                 nla_total_size(1) +
1633                 /* IFLA_IPTUN_TOS */
1634                 nla_total_size(1) +
1635                 /* IFLA_IPTUN_PMTUDISC */
1636                 nla_total_size(1) +
1637                 /* IFLA_IPTUN_FLAGS */
1638                 nla_total_size(2) +
1639                 /* IFLA_IPTUN_PROTO */
1640                 nla_total_size(1) +
1641 #ifdef CONFIG_IPV6_SIT_6RD
1642                 /* IFLA_IPTUN_6RD_PREFIX */
1643                 nla_total_size(sizeof(struct in6_addr)) +
1644                 /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1645                 nla_total_size(4) +
1646                 /* IFLA_IPTUN_6RD_PREFIXLEN */
1647                 nla_total_size(2) +
1648                 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1649                 nla_total_size(2) +
1650 #endif
1651                 /* IFLA_IPTUN_ENCAP_TYPE */
1652                 nla_total_size(2) +
1653                 /* IFLA_IPTUN_ENCAP_FLAGS */
1654                 nla_total_size(2) +
1655                 /* IFLA_IPTUN_ENCAP_SPORT */
1656                 nla_total_size(2) +
1657                 /* IFLA_IPTUN_ENCAP_DPORT */
1658                 nla_total_size(2) +
1659                 0;
1660 }
1661
1662 static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1663 {
1664         struct ip_tunnel *tunnel = netdev_priv(dev);
1665         struct ip_tunnel_parm *parm = &tunnel->parms;
1666
1667         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1668             nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1669             nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1670             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1671             nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1672             nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1673                        !!(parm->iph.frag_off & htons(IP_DF))) ||
1674             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1675             nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags))
1676                 goto nla_put_failure;
1677
1678 #ifdef CONFIG_IPV6_SIT_6RD
1679         if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX,
1680                              &tunnel->ip6rd.prefix) ||
1681             nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1682                             tunnel->ip6rd.relay_prefix) ||
1683             nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1684                         tunnel->ip6rd.prefixlen) ||
1685             nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1686                         tunnel->ip6rd.relay_prefixlen))
1687                 goto nla_put_failure;
1688 #endif
1689
1690         if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
1691                         tunnel->encap.type) ||
1692             nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
1693                         tunnel->encap.sport) ||
1694             nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
1695                         tunnel->encap.dport) ||
1696             nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
1697                         tunnel->encap.flags))
1698                 goto nla_put_failure;
1699
1700         return 0;
1701
1702 nla_put_failure:
1703         return -EMSGSIZE;
1704 }
1705
1706 static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1707         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
1708         [IFLA_IPTUN_LOCAL]              = { .type = NLA_U32 },
1709         [IFLA_IPTUN_REMOTE]             = { .type = NLA_U32 },
1710         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
1711         [IFLA_IPTUN_TOS]                = { .type = NLA_U8 },
1712         [IFLA_IPTUN_PMTUDISC]           = { .type = NLA_U8 },
1713         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U16 },
1714         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
1715 #ifdef CONFIG_IPV6_SIT_6RD
1716         [IFLA_IPTUN_6RD_PREFIX]         = { .len = sizeof(struct in6_addr) },
1717         [IFLA_IPTUN_6RD_RELAY_PREFIX]   = { .type = NLA_U32 },
1718         [IFLA_IPTUN_6RD_PREFIXLEN]      = { .type = NLA_U16 },
1719         [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1720 #endif
1721         [IFLA_IPTUN_ENCAP_TYPE]         = { .type = NLA_U16 },
1722         [IFLA_IPTUN_ENCAP_FLAGS]        = { .type = NLA_U16 },
1723         [IFLA_IPTUN_ENCAP_SPORT]        = { .type = NLA_U16 },
1724         [IFLA_IPTUN_ENCAP_DPORT]        = { .type = NLA_U16 },
1725 };
1726
1727 static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1728 {
1729         struct net *net = dev_net(dev);
1730         struct sit_net *sitn = net_generic(net, sit_net_id);
1731
1732         if (dev != sitn->fb_tunnel_dev)
1733                 unregister_netdevice_queue(dev, head);
1734 }
1735
1736 static struct rtnl_link_ops sit_link_ops __read_mostly = {
1737         .kind           = "sit",
1738         .maxtype        = IFLA_IPTUN_MAX,
1739         .policy         = ipip6_policy,
1740         .priv_size      = sizeof(struct ip_tunnel),
1741         .setup          = ipip6_tunnel_setup,
1742         .validate       = ipip6_validate,
1743         .newlink        = ipip6_newlink,
1744         .changelink     = ipip6_changelink,
1745         .get_size       = ipip6_get_size,
1746         .fill_info      = ipip6_fill_info,
1747         .dellink        = ipip6_dellink,
1748         .get_link_net   = ip_tunnel_get_link_net,
1749 };
1750
1751 static struct xfrm_tunnel sit_handler __read_mostly = {
1752         .handler        =       ipip6_rcv,
1753         .err_handler    =       ipip6_err,
1754         .priority       =       1,
1755 };
1756
1757 static struct xfrm_tunnel ipip_handler __read_mostly = {
1758         .handler        =       ipip_rcv,
1759         .err_handler    =       ipip6_err,
1760         .priority       =       2,
1761 };
1762
1763 static void __net_exit sit_destroy_tunnels(struct net *net,
1764                                            struct list_head *head)
1765 {
1766         struct sit_net *sitn = net_generic(net, sit_net_id);
1767         struct net_device *dev, *aux;
1768         int prio;
1769
1770         for_each_netdev_safe(net, dev, aux)
1771                 if (dev->rtnl_link_ops == &sit_link_ops)
1772                         unregister_netdevice_queue(dev, head);
1773
1774         for (prio = 1; prio < 4; prio++) {
1775                 int h;
1776                 for (h = 0; h < HASH_SIZE; h++) {
1777                         struct ip_tunnel *t;
1778
1779                         t = rtnl_dereference(sitn->tunnels[prio][h]);
1780                         while (t) {
1781                                 /* If dev is in the same netns, it has already
1782                                  * been added to the list by the previous loop.
1783                                  */
1784                                 if (!net_eq(dev_net(t->dev), net))
1785                                         unregister_netdevice_queue(t->dev,
1786                                                                    head);
1787                                 t = rtnl_dereference(t->next);
1788                         }
1789                 }
1790         }
1791 }
1792
1793 static int __net_init sit_init_net(struct net *net)
1794 {
1795         struct sit_net *sitn = net_generic(net, sit_net_id);
1796         struct ip_tunnel *t;
1797         int err;
1798
1799         sitn->tunnels[0] = sitn->tunnels_wc;
1800         sitn->tunnels[1] = sitn->tunnels_l;
1801         sitn->tunnels[2] = sitn->tunnels_r;
1802         sitn->tunnels[3] = sitn->tunnels_r_l;
1803
1804         sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1805                                            NET_NAME_UNKNOWN,
1806                                            ipip6_tunnel_setup);
1807         if (!sitn->fb_tunnel_dev) {
1808                 err = -ENOMEM;
1809                 goto err_alloc_dev;
1810         }
1811         dev_net_set(sitn->fb_tunnel_dev, net);
1812         sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1813         /* FB netdevice is special: we have one, and only one per netns.
1814          * Allowing to move it to another netns is clearly unsafe.
1815          */
1816         sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1817
1818         err = register_netdev(sitn->fb_tunnel_dev);
1819         if (err)
1820                 goto err_reg_dev;
1821
1822         ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1823         ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1824
1825         t = netdev_priv(sitn->fb_tunnel_dev);
1826
1827         strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1828         return 0;
1829
1830 err_reg_dev:
1831         ipip6_dev_free(sitn->fb_tunnel_dev);
1832 err_alloc_dev:
1833         return err;
1834 }
1835
1836 static void __net_exit sit_exit_net(struct net *net)
1837 {
1838         LIST_HEAD(list);
1839
1840         rtnl_lock();
1841         sit_destroy_tunnels(net, &list);
1842         unregister_netdevice_many(&list);
1843         rtnl_unlock();
1844 }
1845
1846 static struct pernet_operations sit_net_ops = {
1847         .init = sit_init_net,
1848         .exit = sit_exit_net,
1849         .id   = &sit_net_id,
1850         .size = sizeof(struct sit_net),
1851 };
1852
1853 static void __exit sit_cleanup(void)
1854 {
1855         rtnl_link_unregister(&sit_link_ops);
1856         xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1857         xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1858
1859         unregister_pernet_device(&sit_net_ops);
1860         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1861 }
1862
1863 static int __init sit_init(void)
1864 {
1865         int err;
1866
1867         pr_info("IPv6 over IPv4 tunneling driver\n");
1868
1869         err = register_pernet_device(&sit_net_ops);
1870         if (err < 0)
1871                 return err;
1872         err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1873         if (err < 0) {
1874                 pr_info("%s: can't register ip6ip4\n", __func__);
1875                 goto xfrm_tunnel_failed;
1876         }
1877         err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1878         if (err < 0) {
1879                 pr_info("%s: can't register ip4ip4\n", __func__);
1880                 goto xfrm_tunnel4_failed;
1881         }
1882         err = rtnl_link_register(&sit_link_ops);
1883         if (err < 0)
1884                 goto rtnl_link_failed;
1885
1886 out:
1887         return err;
1888
1889 rtnl_link_failed:
1890         xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1891 xfrm_tunnel4_failed:
1892         xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1893 xfrm_tunnel_failed:
1894         unregister_pernet_device(&sit_net_ops);
1895         goto out;
1896 }
1897
1898 module_init(sit_init);
1899 module_exit(sit_cleanup);
1900 MODULE_LICENSE("GPL");
1901 MODULE_ALIAS_RTNL_LINK("sit");
1902 MODULE_ALIAS_NETDEV("sit0");