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 != NULL) && (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         err = ipip6_tunnel_init(dev);
 199         if (err < 0)
 200                 goto out;
 201         ipip6_tunnel_clone_6rd(dev, sitn);
 202
 203         if ((__force u16)t->parms.i_flags & SIT_ISATAP)
 204                 dev->priv_flags |= IFF_ISATAP;
 205
 206         err = register_netdevice(dev);
 207         if (err < 0)
 208                 goto out;
 209
 210         strcpy(t->parms.name, dev->name);
 211         dev->rtnl_link_ops = &sit_link_ops;
 212
 213         dev_hold(dev);
 214
 215         ipip6_tunnel_link(sitn, t);
 216         return 0;
 217
 218 out:
 219         return err;
 220 }
 221
 222 static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
 223                 struct ip_tunnel_parm *parms, int create)
 224 {
 225         __be32 remote = parms->iph.daddr;
 226         __be32 local = parms->iph.saddr;
 227         struct ip_tunnel *t, *nt;
 228         struct ip_tunnel __rcu **tp;
 229         struct net_device *dev;
 230         char name[IFNAMSIZ];
 231         struct sit_net *sitn = net_generic(net, sit_net_id);
 232
 233         for (tp = __ipip6_bucket(sitn, parms);
 234             (t = rtnl_dereference(*tp)) != NULL;
 235              tp = &t->next) {
 236                 if (local == t->parms.iph.saddr &&
 237                     remote == t->parms.iph.daddr &&
 238                     parms->link == t->parms.link) {
 239                         if (create)
 240                                 return NULL;
 241                         else
 242                                 return t;
 243                 }
 244         }
 245         if (!create)
 246                 goto failed;
 247
 248         if (parms->name[0])
 249                 strlcpy(name, parms->name, IFNAMSIZ);
 250         else
 251                 strcpy(name, "sit%d");
 252
 253         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 254                            ipip6_tunnel_setup);
 255         if (dev == NULL)
 256                 return NULL;
 257
 258         dev_net_set(dev, net);
 259
 260         nt = netdev_priv(dev);
 261
 262         nt->parms = *parms;
 263         if (ipip6_tunnel_create(dev) < 0)
 264                 goto failed_free;
 265
 266         return nt;
 267
 268 failed_free:
 269         ipip6_dev_free(dev);
 270 failed:
 271         return NULL;
 272 }
 273
 274 #define for_each_prl_rcu(start)                 \
 275         for (prl = rcu_dereference(start);      \
 276              prl;                               \
 277              prl = rcu_dereference(prl->next))
 278
 279 static struct ip_tunnel_prl_entry *
 280 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
 281 {
 282         struct ip_tunnel_prl_entry *prl;
 283
 284         for_each_prl_rcu(t->prl)
 285                 if (prl->addr == addr)
 286                         break;
 287         return prl;
 288
 289 }
 290
 291 static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
 292                                 struct ip_tunnel_prl __user *a)
 293 {
 294         struct ip_tunnel_prl kprl, *kp;
 295         struct ip_tunnel_prl_entry *prl;
 296         unsigned int cmax, c = 0, ca, len;
 297         int ret = 0;
 298
 299         if (copy_from_user(&kprl, a, sizeof(kprl)))
 300                 return -EFAULT;
 301         cmax = kprl.datalen / sizeof(kprl);
 302         if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
 303                 cmax = 1;
 304
 305         /* For simple GET or for root users,
 306          * we try harder to allocate.
 307          */
 308         kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
 309                 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
 310                 NULL;
 311
 312         rcu_read_lock();
 313
 314         ca = t->prl_count < cmax ? t->prl_count : cmax;
 315
 316         if (!kp) {
 317                 /* We don't try hard to allocate much memory for
 318                  * non-root users.
 319                  * For root users, retry allocating enough memory for
 320                  * the answer.
 321                  */
 322                 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
 323                 if (!kp) {
 324                         ret = -ENOMEM;
 325                         goto out;
 326                 }
 327         }
 328
 329         c = 0;
 330         for_each_prl_rcu(t->prl) {
 331                 if (c >= cmax)
 332                         break;
 333                 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
 334                         continue;
 335                 kp[c].addr = prl->addr;
 336                 kp[c].flags = prl->flags;
 337                 c++;
 338                 if (kprl.addr != htonl(INADDR_ANY))
 339                         break;
 340         }
 341 out:
 342         rcu_read_unlock();
 343
 344         len = sizeof(*kp) * c;
 345         ret = 0;
 346         if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
 347                 ret = -EFAULT;
 348
 349         kfree(kp);
 350
 351         return ret;
 352 }
 353
 354 static int
 355 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
 356 {
 357         struct ip_tunnel_prl_entry *p;
 358         int err = 0;
 359
 360         if (a->addr == htonl(INADDR_ANY))
 361                 return -EINVAL;
 362
 363         ASSERT_RTNL();
 364
 365         for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
 366                 if (p->addr == a->addr) {
 367                         if (chg) {
 368                                 p->flags = a->flags;
 369                                 goto out;
 370                         }
 371                         err = -EEXIST;
 372                         goto out;
 373                 }
 374         }
 375
 376         if (chg) {
 377                 err = -ENXIO;
 378                 goto out;
 379         }
 380
 381         p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
 382         if (!p) {
 383                 err = -ENOBUFS;
 384                 goto out;
 385         }
 386
 387         p->next = t->prl;
 388         p->addr = a->addr;
 389         p->flags = a->flags;
 390         t->prl_count++;
 391         rcu_assign_pointer(t->prl, p);
 392 out:
 393         return err;
 394 }
 395
 396 static void prl_list_destroy_rcu(struct rcu_head *head)
 397 {
 398         struct ip_tunnel_prl_entry *p, *n;
 399
 400         p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
 401         do {
 402                 n = rcu_dereference_protected(p->next, 1);
 403                 kfree(p);
 404                 p = n;
 405         } while (p);
 406 }
 407
 408 static int
 409 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
 410 {
 411         struct ip_tunnel_prl_entry *x;
 412         struct ip_tunnel_prl_entry __rcu **p;
 413         int err = 0;
 414
 415         ASSERT_RTNL();
 416
 417         if (a && a->addr != htonl(INADDR_ANY)) {
 418                 for (p = &t->prl;
 419                      (x = rtnl_dereference(*p)) != NULL;
 420                      p = &x->next) {
 421                         if (x->addr == a->addr) {
 422                                 *p = x->next;
 423                                 kfree_rcu(x, rcu_head);
 424                                 t->prl_count--;
 425                                 goto out;
 426                         }
 427                 }
 428                 err = -ENXIO;
 429         } else {
 430                 x = rtnl_dereference(t->prl);
 431                 if (x) {
 432                         t->prl_count = 0;
 433                         call_rcu(&x->rcu_head, prl_list_destroy_rcu);
 434                         t->prl = NULL;
 435                 }
 436         }
 437 out:
 438         return err;
 439 }
 440
 441 static int
 442 isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
 443 {
 444         struct ip_tunnel_prl_entry *p;
 445         int ok = 1;
 446
 447         rcu_read_lock();
 448         p = __ipip6_tunnel_locate_prl(t, iph->saddr);
 449         if (p) {
 450                 if (p->flags & PRL_DEFAULT)
 451                         skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
 452                 else
 453                         skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
 454         } else {
 455                 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
 456
 457                 if (ipv6_addr_is_isatap(addr6) &&
 458                     (addr6->s6_addr32[3] == iph->saddr) &&
 459                     ipv6_chk_prefix(addr6, t->dev))
 460                         skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
 461                 else
 462                         ok = 0;
 463         }
 464         rcu_read_unlock();
 465         return ok;
 466 }
 467
 468 static void ipip6_tunnel_uninit(struct net_device *dev)
 469 {
 470         struct ip_tunnel *tunnel = netdev_priv(dev);
 471         struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
 472
 473         if (dev == sitn->fb_tunnel_dev) {
 474                 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
 475         } else {
 476                 ipip6_tunnel_unlink(sitn, tunnel);
 477                 ipip6_tunnel_del_prl(tunnel, NULL);
 478         }
 479         ip_tunnel_dst_reset_all(tunnel);
 480         dev_put(dev);
 481 }
 482
 483 /* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH
 484  * if sufficient data bytes are available
 485  */
 486 static int ipip6_err_gen_icmpv6_unreach(struct sk_buff *skb)
 487 {
 488         const struct iphdr *iph = (const struct iphdr *) skb->data;
 489         struct rt6_info *rt;
 490         struct sk_buff *skb2;
 491
 492         if (!pskb_may_pull(skb, iph->ihl * 4 + sizeof(struct ipv6hdr) + 8))
 493                 return 1;
 494
 495         skb2 = skb_clone(skb, GFP_ATOMIC);
 496
 497         if (!skb2)
 498                 return 1;
 499
 500         skb_dst_drop(skb2);
 501         skb_pull(skb2, iph->ihl * 4);
 502         skb_reset_network_header(skb2);
 503
 504         rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0, 0);
 505
 506         if (rt && rt->dst.dev)
 507                 skb2->dev = rt->dst.dev;
 508
 509         icmpv6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
 510
 511         if (rt)
 512                 ip6_rt_put(rt);
 513
 514         kfree_skb(skb2);
 515
 516         return 0;
 517 }
 518
 519 static int ipip6_err(struct sk_buff *skb, u32 info)
 520 {
 521         const struct iphdr *iph = (const struct iphdr *)skb->data;
 522         const int type = icmp_hdr(skb)->type;
 523         const int code = icmp_hdr(skb)->code;
 524         struct ip_tunnel *t;
 525         int err;
 526
 527         switch (type) {
 528         default:
 529         case ICMP_PARAMETERPROB:
 530                 return 0;
 531
 532         case ICMP_DEST_UNREACH:
 533                 switch (code) {
 534                 case ICMP_SR_FAILED:
 535                         /* Impossible event. */
 536                         return 0;
 537                 default:
 538                         /* All others are translated to HOST_UNREACH.
 539                            rfc2003 contains "deep thoughts" about NET_UNREACH,
 540                            I believe they are just ether pollution. --ANK
 541                          */
 542                         break;
 543                 }
 544                 break;
 545         case ICMP_TIME_EXCEEDED:
 546                 if (code != ICMP_EXC_TTL)
 547                         return 0;
 548                 break;
 549         case ICMP_REDIRECT:
 550                 break;
 551         }
 552
 553         err = -ENOENT;
 554
 555         t = ipip6_tunnel_lookup(dev_net(skb->dev),
 556                                 skb->dev,
 557                                 iph->daddr,
 558                                 iph->saddr);
 559         if (t == NULL)
 560                 goto out;
 561
 562         if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
 563                 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
 564                                  t->parms.link, 0, IPPROTO_IPV6, 0);
 565                 err = 0;
 566                 goto out;
 567         }
 568         if (type == ICMP_REDIRECT) {
 569                 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
 570                               IPPROTO_IPV6, 0);
 571                 err = 0;
 572                 goto out;
 573         }
 574
 575         if (t->parms.iph.daddr == 0)
 576                 goto out;
 577
 578         err = 0;
 579         if (!ipip6_err_gen_icmpv6_unreach(skb))
 580                 goto out;
 581
 582         if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
 583                 goto out;
 584
 585         if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
 586                 t->err_count++;
 587         else
 588                 t->err_count = 1;
 589         t->err_time = jiffies;
 590 out:
 591         return err;
 592 }
 593
 594 static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
 595                                   const struct in6_addr *v6addr)
 596 {
 597         __be32 v4embed = 0;
 598         if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
 599                 return true;
 600         return false;
 601 }
 602
 603 /* Checks if an address matches an address on the tunnel interface.
 604  * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
 605  * Long story:
 606  * This function is called after we considered the packet as spoofed
 607  * in is_spoofed_6rd.
 608  * We may have a router that is doing NAT for proto 41 packets
 609  * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
 610  * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
 611  * function will return true, dropping the packet.
 612  * But, we can still check if is spoofed against the IP
 613  * addresses associated with the interface.
 614  */
 615 static bool only_dnatted(const struct ip_tunnel *tunnel,
 616         const struct in6_addr *v6dst)
 617 {
 618         int prefix_len;
 619
 620 #ifdef CONFIG_IPV6_SIT_6RD
 621         prefix_len = tunnel->ip6rd.prefixlen + 32
 622                 - tunnel->ip6rd.relay_prefixlen;
 623 #else
 624         prefix_len = 48;
 625 #endif
 626         return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
 627 }
 628
 629 /* Returns true if a packet is spoofed */
 630 static bool packet_is_spoofed(struct sk_buff *skb,
 631                               const struct iphdr *iph,
 632                               struct ip_tunnel *tunnel)
 633 {
 634         const struct ipv6hdr *ipv6h;
 635
 636         if (tunnel->dev->priv_flags & IFF_ISATAP) {
 637                 if (!isatap_chksrc(skb, iph, tunnel))
 638                         return true;
 639
 640                 return false;
 641         }
 642
 643         if (tunnel->dev->flags & IFF_POINTOPOINT)
 644                 return false;
 645
 646         ipv6h = ipv6_hdr(skb);
 647
 648         if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
 649                 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
 650                                      &iph->saddr, &ipv6h->saddr,
 651                                      &iph->daddr, &ipv6h->daddr);
 652                 return true;
 653         }
 654
 655         if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
 656                 return false;
 657
 658         if (only_dnatted(tunnel, &ipv6h->daddr))
 659                 return false;
 660
 661         net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
 662                              &iph->saddr, &ipv6h->saddr,
 663                              &iph->daddr, &ipv6h->daddr);
 664         return true;
 665 }
 666
 667 static int ipip6_rcv(struct sk_buff *skb)
 668 {
 669         const struct iphdr *iph = ip_hdr(skb);
 670         struct ip_tunnel *tunnel;
 671         int err;
 672
 673         tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 674                                      iph->saddr, iph->daddr);
 675         if (tunnel != NULL) {
 676                 struct pcpu_sw_netstats *tstats;
 677
 678                 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
 679                     tunnel->parms.iph.protocol != 0)
 680                         goto out;
 681
 682                 skb->mac_header = skb->network_header;
 683                 skb_reset_network_header(skb);
 684                 IPCB(skb)->flags = 0;
 685                 skb->protocol = htons(ETH_P_IPV6);
 686
 687                 if (packet_is_spoofed(skb, iph, tunnel)) {
 688                         tunnel->dev->stats.rx_errors++;
 689                         goto out;
 690                 }
 691
 692                 __skb_tunnel_rx(skb, tunnel->dev, tunnel->net);
 693
 694                 err = IP_ECN_decapsulate(iph, skb);
 695                 if (unlikely(err)) {
 696                         if (log_ecn_error)
 697                                 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
 698                                                      &iph->saddr, iph->tos);
 699                         if (err > 1) {
 700                                 ++tunnel->dev->stats.rx_frame_errors;
 701                                 ++tunnel->dev->stats.rx_errors;
 702                                 goto out;
 703                         }
 704                 }
 705
 706                 tstats = this_cpu_ptr(tunnel->dev->tstats);
 707                 u64_stats_update_begin(&tstats->syncp);
 708                 tstats->rx_packets++;
 709                 tstats->rx_bytes += skb->len;
 710                 u64_stats_update_end(&tstats->syncp);
 711
 712                 netif_rx(skb);
 713
 714                 return 0;
 715         }
 716
 717         /* no tunnel matched,  let upstream know, ipsec may handle it */
 718         return 1;
 719 out:
 720         kfree_skb(skb);
 721         return 0;
 722 }
 723
 724 static const struct tnl_ptk_info tpi = {
 725         /* no tunnel info required for ipip. */
 726         .proto = htons(ETH_P_IP),
 727 };
 728
 729 static int ipip_rcv(struct sk_buff *skb)
 730 {
 731         const struct iphdr *iph;
 732         struct ip_tunnel *tunnel;
 733
 734         iph = ip_hdr(skb);
 735         tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 736                                      iph->saddr, iph->daddr);
 737         if (tunnel != NULL) {
 738                 if (tunnel->parms.iph.protocol != IPPROTO_IPIP &&
 739                     tunnel->parms.iph.protocol != 0)
 740                         goto drop;
 741
 742                 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
 743                         goto drop;
 744                 if (iptunnel_pull_header(skb, 0, tpi.proto))
 745                         goto drop;
 746                 return ip_tunnel_rcv(tunnel, skb, &tpi, log_ecn_error);
 747         }
 748
 749         return 1;
 750
 751 drop:
 752         kfree_skb(skb);
 753         return 0;
 754 }
 755
 756 /*
 757  * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
 758  * stores the embedded IPv4 address in v4dst and returns true.
 759  */
 760 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
 761                       __be32 *v4dst)
 762 {
 763 #ifdef CONFIG_IPV6_SIT_6RD
 764         if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
 765                               tunnel->ip6rd.prefixlen)) {
 766                 unsigned int pbw0, pbi0;
 767                 int pbi1;
 768                 u32 d;
 769
 770                 pbw0 = tunnel->ip6rd.prefixlen >> 5;
 771                 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
 772
 773                 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
 774                     tunnel->ip6rd.relay_prefixlen;
 775
 776                 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
 777                 if (pbi1 > 0)
 778                         d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
 779                              (32 - pbi1);
 780
 781                 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
 782                 return true;
 783         }
 784 #else
 785         if (v6dst->s6_addr16[0] == htons(0x2002)) {
 786                 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
 787                 memcpy(v4dst, &v6dst->s6_addr16[1], 4);
 788                 return true;
 789         }
 790 #endif
 791         return false;
 792 }
 793
 794 static inline __be32 try_6rd(struct ip_tunnel *tunnel,
 795                              const struct in6_addr *v6dst)
 796 {
 797         __be32 dst = 0;
 798         check_6rd(tunnel, v6dst, &dst);
 799         return dst;
 800 }
 801
 802 /*
 803  *      This function assumes it is being called from dev_queue_xmit()
 804  *      and that skb is filled properly by that function.
 805  */
 806
 807 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 808                                      struct net_device *dev)
 809 {
 810         struct ip_tunnel *tunnel = netdev_priv(dev);
 811         const struct iphdr  *tiph = &tunnel->parms.iph;
 812         const struct ipv6hdr *iph6 = ipv6_hdr(skb);
 813         u8     tos = tunnel->parms.iph.tos;
 814         __be16 df = tiph->frag_off;
 815         struct rtable *rt;              /* Route to the other host */
 816         struct net_device *tdev;        /* Device to other host */
 817         unsigned int max_headroom;      /* The extra header space needed */
 818         __be32 dst = tiph->daddr;
 819         struct flowi4 fl4;
 820         int    mtu;
 821         const struct in6_addr *addr6;
 822         int addr_type;
 823         u8 ttl;
 824         int err;
 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 == NULL) {
 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 == NULL) {
 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         skb = iptunnel_handle_offloads(skb, false, SKB_GSO_SIT);
 917         if (IS_ERR(skb)) {
 918                 ip_rt_put(rt);
 919                 goto out;
 920         }
 921
 922         if (df) {
 923                 mtu = dst_mtu(&rt->dst) - t_hlen;
 924
 925                 if (mtu < 68) {
 926                         dev->stats.collisions++;
 927                         ip_rt_put(rt);
 928                         goto tx_error;
 929                 }
 930
 931                 if (mtu < IPV6_MIN_MTU) {
 932                         mtu = IPV6_MIN_MTU;
 933                         df = 0;
 934                 }
 935
 936                 if (tunnel->parms.iph.daddr && skb_dst(skb))
 937                         skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 938
 939                 if (skb->len > mtu && !skb_is_gso(skb)) {
 940                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 941                         ip_rt_put(rt);
 942                         goto tx_error;
 943                 }
 944         }
 945
 946         if (tunnel->err_count > 0) {
 947                 if (time_before(jiffies,
 948                                 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
 949                         tunnel->err_count--;
 950                         dst_link_failure(skb);
 951                 } else
 952                         tunnel->err_count = 0;
 953         }
 954
 955         /*
 956          * Okay, now see if we can stuff it in the buffer as-is.
 957          */
 958         max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
 959
 960         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 961             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 962                 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
 963                 if (!new_skb) {
 964                         ip_rt_put(rt);
 965                         dev->stats.tx_dropped++;
 966                         kfree_skb(skb);
 967                         return NETDEV_TX_OK;
 968                 }
 969                 if (skb->sk)
 970                         skb_set_owner_w(new_skb, skb->sk);
 971                 dev_kfree_skb(skb);
 972                 skb = new_skb;
 973                 iph6 = ipv6_hdr(skb);
 974         }
 975         ttl = tiph->ttl;
 976         if (ttl == 0)
 977                 ttl = iph6->hop_limit;
 978         tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
 979
 980         if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) {
 981                 ip_rt_put(rt);
 982                 goto tx_error;
 983         }
 984
 985         skb_set_inner_ipproto(skb, IPPROTO_IPV6);
 986
 987         err = iptunnel_xmit(skb->sk, rt, skb, fl4.saddr, fl4.daddr,
 988                             protocol, tos, ttl, df,
 989                             !net_eq(tunnel->net, dev_net(dev)));
 990         iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
 991         return NETDEV_TX_OK;
 992
 993 tx_error_icmp:
 994         dst_link_failure(skb);
 995 tx_error:
 996         kfree_skb(skb);
 997 out:
 998         dev->stats.tx_errors++;
 999         return NETDEV_TX_OK;
1000 }
1001
1002 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
1003 {
1004         struct ip_tunnel *tunnel = netdev_priv(dev);
1005         const struct iphdr  *tiph = &tunnel->parms.iph;
1006
1007         skb = iptunnel_handle_offloads(skb, false, SKB_GSO_IPIP);
1008         if (IS_ERR(skb))
1009                 goto out;
1010
1011         skb_set_inner_ipproto(skb, IPPROTO_IPIP);
1012
1013         ip_tunnel_xmit(skb, dev, tiph, IPPROTO_IPIP);
1014         return NETDEV_TX_OK;
1015 out:
1016         dev->stats.tx_errors++;
1017         return NETDEV_TX_OK;
1018 }
1019
1020 static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1021                                    struct net_device *dev)
1022 {
1023         switch (skb->protocol) {
1024         case htons(ETH_P_IP):
1025                 ipip_tunnel_xmit(skb, dev);
1026                 break;
1027         case htons(ETH_P_IPV6):
1028                 ipip6_tunnel_xmit(skb, dev);
1029                 break;
1030         default:
1031                 goto tx_err;
1032         }
1033
1034         return NETDEV_TX_OK;
1035
1036 tx_err:
1037         dev->stats.tx_errors++;
1038         kfree_skb(skb);
1039         return NETDEV_TX_OK;
1040
1041 }
1042
1043 static void ipip6_tunnel_bind_dev(struct net_device *dev)
1044 {
1045         struct net_device *tdev = NULL;
1046         struct ip_tunnel *tunnel;
1047         const struct iphdr *iph;
1048         struct flowi4 fl4;
1049
1050         tunnel = netdev_priv(dev);
1051         iph = &tunnel->parms.iph;
1052
1053         if (iph->daddr) {
1054                 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1055                                                           NULL,
1056                                                           iph->daddr, iph->saddr,
1057                                                           0, 0,
1058                                                           IPPROTO_IPV6,
1059                                                           RT_TOS(iph->tos),
1060                                                           tunnel->parms.link);
1061
1062                 if (!IS_ERR(rt)) {
1063                         tdev = rt->dst.dev;
1064                         ip_rt_put(rt);
1065                 }
1066                 dev->flags |= IFF_POINTOPOINT;
1067         }
1068
1069         if (!tdev && tunnel->parms.link)
1070                 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1071
1072         if (tdev) {
1073                 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1074
1075                 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
1076                 dev->mtu = tdev->mtu - t_hlen;
1077                 if (dev->mtu < IPV6_MIN_MTU)
1078                         dev->mtu = IPV6_MIN_MTU;
1079         }
1080         dev->iflink = tunnel->parms.link;
1081 }
1082
1083 static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p)
1084 {
1085         struct net *net = t->net;
1086         struct sit_net *sitn = net_generic(net, sit_net_id);
1087
1088         ipip6_tunnel_unlink(sitn, t);
1089         synchronize_net();
1090         t->parms.iph.saddr = p->iph.saddr;
1091         t->parms.iph.daddr = p->iph.daddr;
1092         memcpy(t->dev->dev_addr, &p->iph.saddr, 4);
1093         memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1094         ipip6_tunnel_link(sitn, t);
1095         t->parms.iph.ttl = p->iph.ttl;
1096         t->parms.iph.tos = p->iph.tos;
1097         if (t->parms.link != p->link) {
1098                 t->parms.link = p->link;
1099                 ipip6_tunnel_bind_dev(t->dev);
1100         }
1101         ip_tunnel_dst_reset_all(t);
1102         netdev_state_change(t->dev);
1103 }
1104
1105 #ifdef CONFIG_IPV6_SIT_6RD
1106 static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1107                                    struct ip_tunnel_6rd *ip6rd)
1108 {
1109         struct in6_addr prefix;
1110         __be32 relay_prefix;
1111
1112         if (ip6rd->relay_prefixlen > 32 ||
1113             ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1114                 return -EINVAL;
1115
1116         ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1117         if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1118                 return -EINVAL;
1119         if (ip6rd->relay_prefixlen)
1120                 relay_prefix = ip6rd->relay_prefix &
1121                                htonl(0xffffffffUL <<
1122                                      (32 - ip6rd->relay_prefixlen));
1123         else
1124                 relay_prefix = 0;
1125         if (relay_prefix != ip6rd->relay_prefix)
1126                 return -EINVAL;
1127
1128         t->ip6rd.prefix = prefix;
1129         t->ip6rd.relay_prefix = relay_prefix;
1130         t->ip6rd.prefixlen = ip6rd->prefixlen;
1131         t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1132         ip_tunnel_dst_reset_all(t);
1133         netdev_state_change(t->dev);
1134         return 0;
1135 }
1136 #endif
1137
1138 static int
1139 ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1140 {
1141         int err = 0;
1142         struct ip_tunnel_parm p;
1143         struct ip_tunnel_prl prl;
1144         struct ip_tunnel *t = netdev_priv(dev);
1145         struct net *net = t->net;
1146         struct sit_net *sitn = net_generic(net, sit_net_id);
1147 #ifdef CONFIG_IPV6_SIT_6RD
1148         struct ip_tunnel_6rd ip6rd;
1149 #endif
1150
1151         switch (cmd) {
1152         case SIOCGETTUNNEL:
1153 #ifdef CONFIG_IPV6_SIT_6RD
1154         case SIOCGET6RD:
1155 #endif
1156                 if (dev == sitn->fb_tunnel_dev) {
1157                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1158                                 err = -EFAULT;
1159                                 break;
1160                         }
1161                         t = ipip6_tunnel_locate(net, &p, 0);
1162                         if (t == NULL)
1163                                 t = netdev_priv(dev);
1164                 }
1165
1166                 err = -EFAULT;
1167                 if (cmd == SIOCGETTUNNEL) {
1168                         memcpy(&p, &t->parms, sizeof(p));
1169                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
1170                                          sizeof(p)))
1171                                 goto done;
1172 #ifdef CONFIG_IPV6_SIT_6RD
1173                 } else {
1174                         ip6rd.prefix = t->ip6rd.prefix;
1175                         ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1176                         ip6rd.prefixlen = t->ip6rd.prefixlen;
1177                         ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1178                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
1179                                          sizeof(ip6rd)))
1180                                 goto done;
1181 #endif
1182                 }
1183                 err = 0;
1184                 break;
1185
1186         case SIOCADDTUNNEL:
1187         case SIOCCHGTUNNEL:
1188                 err = -EPERM;
1189                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1190                         goto done;
1191
1192                 err = -EFAULT;
1193                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1194                         goto done;
1195
1196                 err = -EINVAL;
1197                 if (p.iph.protocol != IPPROTO_IPV6 &&
1198                     p.iph.protocol != IPPROTO_IPIP &&
1199                     p.iph.protocol != 0)
1200                         goto done;
1201                 if (p.iph.version != 4 ||
1202                     p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
1203                         goto done;
1204                 if (p.iph.ttl)
1205                         p.iph.frag_off |= htons(IP_DF);
1206
1207                 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1208
1209                 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1210                         if (t != NULL) {
1211                                 if (t->dev != dev) {
1212                                         err = -EEXIST;
1213                                         break;
1214                                 }
1215                         } else {
1216                                 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
1217                                     (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
1218                                         err = -EINVAL;
1219                                         break;
1220                                 }
1221                                 t = netdev_priv(dev);
1222                         }
1223
1224                         ipip6_tunnel_update(t, &p);
1225                 }
1226
1227                 if (t) {
1228                         err = 0;
1229                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1230                                 err = -EFAULT;
1231                 } else
1232                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1233                 break;
1234
1235         case SIOCDELTUNNEL:
1236                 err = -EPERM;
1237                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1238                         goto done;
1239
1240                 if (dev == sitn->fb_tunnel_dev) {
1241                         err = -EFAULT;
1242                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1243                                 goto done;
1244                         err = -ENOENT;
1245                         if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
1246                                 goto done;
1247                         err = -EPERM;
1248                         if (t == netdev_priv(sitn->fb_tunnel_dev))
1249                                 goto done;
1250                         dev = t->dev;
1251                 }
1252                 unregister_netdevice(dev);
1253                 err = 0;
1254                 break;
1255
1256         case SIOCGETPRL:
1257                 err = -EINVAL;
1258                 if (dev == sitn->fb_tunnel_dev)
1259                         goto done;
1260                 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1261                 break;
1262
1263         case SIOCADDPRL:
1264         case SIOCDELPRL:
1265         case SIOCCHGPRL:
1266                 err = -EPERM;
1267                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1268                         goto done;
1269                 err = -EINVAL;
1270                 if (dev == sitn->fb_tunnel_dev)
1271                         goto done;
1272                 err = -EFAULT;
1273                 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1274                         goto done;
1275
1276                 switch (cmd) {
1277                 case SIOCDELPRL:
1278                         err = ipip6_tunnel_del_prl(t, &prl);
1279                         break;
1280                 case SIOCADDPRL:
1281                 case SIOCCHGPRL:
1282                         err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1283                         break;
1284                 }
1285                 ip_tunnel_dst_reset_all(t);
1286                 netdev_state_change(dev);
1287                 break;
1288
1289 #ifdef CONFIG_IPV6_SIT_6RD
1290         case SIOCADD6RD:
1291         case SIOCCHG6RD:
1292         case SIOCDEL6RD:
1293                 err = -EPERM;
1294                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1295                         goto done;
1296
1297                 err = -EFAULT;
1298                 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1299                                    sizeof(ip6rd)))
1300                         goto done;
1301
1302                 if (cmd != SIOCDEL6RD) {
1303                         err = ipip6_tunnel_update_6rd(t, &ip6rd);
1304                         if (err < 0)
1305                                 goto done;
1306                 } else
1307                         ipip6_tunnel_clone_6rd(dev, sitn);
1308
1309                 err = 0;
1310                 break;
1311 #endif
1312
1313         default:
1314                 err = -EINVAL;
1315         }
1316
1317 done:
1318         return err;
1319 }
1320
1321 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1322 {
1323         struct ip_tunnel *tunnel = netdev_priv(dev);
1324         int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1325
1326         if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - t_hlen)
1327                 return -EINVAL;
1328         dev->mtu = new_mtu;
1329         return 0;
1330 }
1331
1332 static const struct net_device_ops ipip6_netdev_ops = {
1333         .ndo_uninit     = ipip6_tunnel_uninit,
1334         .ndo_start_xmit = sit_tunnel_xmit,
1335         .ndo_do_ioctl   = ipip6_tunnel_ioctl,
1336         .ndo_change_mtu = ipip6_tunnel_change_mtu,
1337         .ndo_get_stats64 = ip_tunnel_get_stats64,
1338 };
1339
1340 static void ipip6_dev_free(struct net_device *dev)
1341 {
1342         struct ip_tunnel *tunnel = netdev_priv(dev);
1343
1344         free_percpu(tunnel->dst_cache);
1345         free_percpu(dev->tstats);
1346         free_netdev(dev);
1347 }
1348
1349 #define SIT_FEATURES (NETIF_F_SG           | \
1350                       NETIF_F_FRAGLIST     | \
1351                       NETIF_F_HIGHDMA      | \
1352                       NETIF_F_GSO_SOFTWARE | \
1353                       NETIF_F_HW_CSUM)
1354
1355 static void ipip6_tunnel_setup(struct net_device *dev)
1356 {
1357         struct ip_tunnel *tunnel = netdev_priv(dev);
1358         int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1359
1360         dev->netdev_ops         = &ipip6_netdev_ops;
1361         dev->destructor         = ipip6_dev_free;
1362
1363         dev->type               = ARPHRD_SIT;
1364         dev->hard_header_len    = LL_MAX_HEADER + t_hlen;
1365         dev->mtu                = ETH_DATA_LEN - t_hlen;
1366         dev->flags              = IFF_NOARP;
1367         netif_keep_dst(dev);
1368         dev->iflink             = 0;
1369         dev->addr_len           = 4;
1370         dev->features           |= NETIF_F_LLTX;
1371         dev->features           |= SIT_FEATURES;
1372         dev->hw_features        |= SIT_FEATURES;
1373 }
1374
1375 static int ipip6_tunnel_init(struct net_device *dev)
1376 {
1377         struct ip_tunnel *tunnel = netdev_priv(dev);
1378
1379         tunnel->dev = dev;
1380         tunnel->net = dev_net(dev);
1381
1382         memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1383         memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1384
1385         ipip6_tunnel_bind_dev(dev);
1386         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1387         if (!dev->tstats)
1388                 return -ENOMEM;
1389
1390         tunnel->dst_cache = alloc_percpu(struct ip_tunnel_dst);
1391         if (!tunnel->dst_cache) {
1392                 free_percpu(dev->tstats);
1393                 return -ENOMEM;
1394         }
1395
1396         return 0;
1397 }
1398
1399 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1400 {
1401         struct ip_tunnel *tunnel = netdev_priv(dev);
1402         struct iphdr *iph = &tunnel->parms.iph;
1403         struct net *net = dev_net(dev);
1404         struct sit_net *sitn = net_generic(net, sit_net_id);
1405
1406         tunnel->dev = dev;
1407         tunnel->net = dev_net(dev);
1408         strcpy(tunnel->parms.name, dev->name);
1409
1410         iph->version            = 4;
1411         iph->protocol           = IPPROTO_IPV6;
1412         iph->ihl                = 5;
1413         iph->ttl                = 64;
1414
1415         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1416         if (!dev->tstats)
1417                 return -ENOMEM;
1418
1419         tunnel->dst_cache = alloc_percpu(struct ip_tunnel_dst);
1420         if (!tunnel->dst_cache) {
1421                 free_percpu(dev->tstats);
1422                 return -ENOMEM;
1423         }
1424
1425         dev_hold(dev);
1426         rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1427         return 0;
1428 }
1429
1430 static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[])
1431 {
1432         u8 proto;
1433
1434         if (!data || !data[IFLA_IPTUN_PROTO])
1435                 return 0;
1436
1437         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1438         if (proto != IPPROTO_IPV6 &&
1439             proto != IPPROTO_IPIP &&
1440             proto != 0)
1441                 return -EINVAL;
1442
1443         return 0;
1444 }
1445
1446 static void ipip6_netlink_parms(struct nlattr *data[],
1447                                 struct ip_tunnel_parm *parms)
1448 {
1449         memset(parms, 0, sizeof(*parms));
1450
1451         parms->iph.version = 4;
1452         parms->iph.protocol = IPPROTO_IPV6;
1453         parms->iph.ihl = 5;
1454         parms->iph.ttl = 64;
1455
1456         if (!data)
1457                 return;
1458
1459         if (data[IFLA_IPTUN_LINK])
1460                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1461
1462         if (data[IFLA_IPTUN_LOCAL])
1463                 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1464
1465         if (data[IFLA_IPTUN_REMOTE])
1466                 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1467
1468         if (data[IFLA_IPTUN_TTL]) {
1469                 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1470                 if (parms->iph.ttl)
1471                         parms->iph.frag_off = htons(IP_DF);
1472         }
1473
1474         if (data[IFLA_IPTUN_TOS])
1475                 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1476
1477         if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1478                 parms->iph.frag_off = htons(IP_DF);
1479
1480         if (data[IFLA_IPTUN_FLAGS])
1481                 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1482
1483         if (data[IFLA_IPTUN_PROTO])
1484                 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1485
1486 }
1487
1488 /* This function returns true when ENCAP attributes are present in the nl msg */
1489 static bool ipip6_netlink_encap_parms(struct nlattr *data[],
1490                                       struct ip_tunnel_encap *ipencap)
1491 {
1492         bool ret = false;
1493
1494         memset(ipencap, 0, sizeof(*ipencap));
1495
1496         if (!data)
1497                 return ret;
1498
1499         if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1500                 ret = true;
1501                 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1502         }
1503
1504         if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1505                 ret = true;
1506                 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1507         }
1508
1509         if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1510                 ret = true;
1511                 ipencap->sport = nla_get_u16(data[IFLA_IPTUN_ENCAP_SPORT]);
1512         }
1513
1514         if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1515                 ret = true;
1516                 ipencap->dport = nla_get_u16(data[IFLA_IPTUN_ENCAP_DPORT]);
1517         }
1518
1519         return ret;
1520 }
1521
1522 #ifdef CONFIG_IPV6_SIT_6RD
1523 /* This function returns true when 6RD attributes are present in the nl msg */
1524 static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1525                                     struct ip_tunnel_6rd *ip6rd)
1526 {
1527         bool ret = false;
1528         memset(ip6rd, 0, sizeof(*ip6rd));
1529
1530         if (!data)
1531                 return ret;
1532
1533         if (data[IFLA_IPTUN_6RD_PREFIX]) {
1534                 ret = true;
1535                 nla_memcpy(&ip6rd->prefix, data[IFLA_IPTUN_6RD_PREFIX],
1536                            sizeof(struct in6_addr));
1537         }
1538
1539         if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1540                 ret = true;
1541                 ip6rd->relay_prefix =
1542                         nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1543         }
1544
1545         if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1546                 ret = true;
1547                 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1548         }
1549
1550         if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1551                 ret = true;
1552                 ip6rd->relay_prefixlen =
1553                         nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1554         }
1555
1556         return ret;
1557 }
1558 #endif
1559
1560 static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1561                          struct nlattr *tb[], struct nlattr *data[])
1562 {
1563         struct net *net = dev_net(dev);
1564         struct ip_tunnel *nt;
1565         struct ip_tunnel_encap ipencap;
1566 #ifdef CONFIG_IPV6_SIT_6RD
1567         struct ip_tunnel_6rd ip6rd;
1568 #endif
1569         int err;
1570
1571         nt = netdev_priv(dev);
1572
1573         if (ipip6_netlink_encap_parms(data, &ipencap)) {
1574                 err = ip_tunnel_encap_setup(nt, &ipencap);
1575                 if (err < 0)
1576                         return err;
1577         }
1578
1579         ipip6_netlink_parms(data, &nt->parms);
1580
1581         if (ipip6_tunnel_locate(net, &nt->parms, 0))
1582                 return -EEXIST;
1583
1584         err = ipip6_tunnel_create(dev);
1585         if (err < 0)
1586                 return err;
1587
1588 #ifdef CONFIG_IPV6_SIT_6RD
1589         if (ipip6_netlink_6rd_parms(data, &ip6rd))
1590                 err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1591 #endif
1592
1593         return err;
1594 }
1595
1596 static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1597                           struct nlattr *data[])
1598 {
1599         struct ip_tunnel *t = netdev_priv(dev);
1600         struct ip_tunnel_parm p;
1601         struct ip_tunnel_encap ipencap;
1602         struct net *net = t->net;
1603         struct sit_net *sitn = net_generic(net, sit_net_id);
1604 #ifdef CONFIG_IPV6_SIT_6RD
1605         struct ip_tunnel_6rd ip6rd;
1606 #endif
1607         int err;
1608
1609         if (dev == sitn->fb_tunnel_dev)
1610                 return -EINVAL;
1611
1612         if (ipip6_netlink_encap_parms(data, &ipencap)) {
1613                 err = ip_tunnel_encap_setup(t, &ipencap);
1614                 if (err < 0)
1615                         return err;
1616         }
1617
1618         ipip6_netlink_parms(data, &p);
1619
1620         if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1621             (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1622                 return -EINVAL;
1623
1624         t = ipip6_tunnel_locate(net, &p, 0);
1625
1626         if (t) {
1627                 if (t->dev != dev)
1628                         return -EEXIST;
1629         } else
1630                 t = netdev_priv(dev);
1631
1632         ipip6_tunnel_update(t, &p);
1633
1634 #ifdef CONFIG_IPV6_SIT_6RD
1635         if (ipip6_netlink_6rd_parms(data, &ip6rd))
1636                 return ipip6_tunnel_update_6rd(t, &ip6rd);
1637 #endif
1638
1639         return 0;
1640 }
1641
1642 static size_t ipip6_get_size(const struct net_device *dev)
1643 {
1644         return
1645                 /* IFLA_IPTUN_LINK */
1646                 nla_total_size(4) +
1647                 /* IFLA_IPTUN_LOCAL */
1648                 nla_total_size(4) +
1649                 /* IFLA_IPTUN_REMOTE */
1650                 nla_total_size(4) +
1651                 /* IFLA_IPTUN_TTL */
1652                 nla_total_size(1) +
1653                 /* IFLA_IPTUN_TOS */
1654                 nla_total_size(1) +
1655                 /* IFLA_IPTUN_PMTUDISC */
1656                 nla_total_size(1) +
1657                 /* IFLA_IPTUN_FLAGS */
1658                 nla_total_size(2) +
1659                 /* IFLA_IPTUN_PROTO */
1660                 nla_total_size(1) +
1661 #ifdef CONFIG_IPV6_SIT_6RD
1662                 /* IFLA_IPTUN_6RD_PREFIX */
1663                 nla_total_size(sizeof(struct in6_addr)) +
1664                 /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1665                 nla_total_size(4) +
1666                 /* IFLA_IPTUN_6RD_PREFIXLEN */
1667                 nla_total_size(2) +
1668                 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1669                 nla_total_size(2) +
1670 #endif
1671                 /* IFLA_IPTUN_ENCAP_TYPE */
1672                 nla_total_size(2) +
1673                 /* IFLA_IPTUN_ENCAP_FLAGS */
1674                 nla_total_size(2) +
1675                 /* IFLA_IPTUN_ENCAP_SPORT */
1676                 nla_total_size(2) +
1677                 /* IFLA_IPTUN_ENCAP_DPORT */
1678                 nla_total_size(2) +
1679                 0;
1680 }
1681
1682 static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1683 {
1684         struct ip_tunnel *tunnel = netdev_priv(dev);
1685         struct ip_tunnel_parm *parm = &tunnel->parms;
1686
1687         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1688             nla_put_be32(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1689             nla_put_be32(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1690             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1691             nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1692             nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1693                        !!(parm->iph.frag_off & htons(IP_DF))) ||
1694             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1695             nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags))
1696                 goto nla_put_failure;
1697
1698 #ifdef CONFIG_IPV6_SIT_6RD
1699         if (nla_put(skb, IFLA_IPTUN_6RD_PREFIX, sizeof(struct in6_addr),
1700                     &tunnel->ip6rd.prefix) ||
1701             nla_put_be32(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1702                          tunnel->ip6rd.relay_prefix) ||
1703             nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1704                         tunnel->ip6rd.prefixlen) ||
1705             nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1706                         tunnel->ip6rd.relay_prefixlen))
1707                 goto nla_put_failure;
1708 #endif
1709
1710         if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
1711                         tunnel->encap.type) ||
1712             nla_put_u16(skb, IFLA_IPTUN_ENCAP_SPORT,
1713                         tunnel->encap.sport) ||
1714             nla_put_u16(skb, IFLA_IPTUN_ENCAP_DPORT,
1715                         tunnel->encap.dport) ||
1716             nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
1717                         tunnel->encap.dport))
1718                 goto nla_put_failure;
1719
1720         return 0;
1721
1722 nla_put_failure:
1723         return -EMSGSIZE;
1724 }
1725
1726 static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1727         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
1728         [IFLA_IPTUN_LOCAL]              = { .type = NLA_U32 },
1729         [IFLA_IPTUN_REMOTE]             = { .type = NLA_U32 },
1730         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
1731         [IFLA_IPTUN_TOS]                = { .type = NLA_U8 },
1732         [IFLA_IPTUN_PMTUDISC]           = { .type = NLA_U8 },
1733         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U16 },
1734         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
1735 #ifdef CONFIG_IPV6_SIT_6RD
1736         [IFLA_IPTUN_6RD_PREFIX]         = { .len = sizeof(struct in6_addr) },
1737         [IFLA_IPTUN_6RD_RELAY_PREFIX]   = { .type = NLA_U32 },
1738         [IFLA_IPTUN_6RD_PREFIXLEN]      = { .type = NLA_U16 },
1739         [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1740 #endif
1741         [IFLA_IPTUN_ENCAP_TYPE]         = { .type = NLA_U16 },
1742         [IFLA_IPTUN_ENCAP_FLAGS]        = { .type = NLA_U16 },
1743         [IFLA_IPTUN_ENCAP_SPORT]        = { .type = NLA_U16 },
1744         [IFLA_IPTUN_ENCAP_DPORT]        = { .type = NLA_U16 },
1745 };
1746
1747 static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1748 {
1749         struct net *net = dev_net(dev);
1750         struct sit_net *sitn = net_generic(net, sit_net_id);
1751
1752         if (dev != sitn->fb_tunnel_dev)
1753                 unregister_netdevice_queue(dev, head);
1754 }
1755
1756 static struct rtnl_link_ops sit_link_ops __read_mostly = {
1757         .kind           = "sit",
1758         .maxtype        = IFLA_IPTUN_MAX,
1759         .policy         = ipip6_policy,
1760         .priv_size      = sizeof(struct ip_tunnel),
1761         .setup          = ipip6_tunnel_setup,
1762         .validate       = ipip6_validate,
1763         .newlink        = ipip6_newlink,
1764         .changelink     = ipip6_changelink,
1765         .get_size       = ipip6_get_size,
1766         .fill_info      = ipip6_fill_info,
1767         .dellink        = ipip6_dellink,
1768 };
1769
1770 static struct xfrm_tunnel sit_handler __read_mostly = {
1771         .handler        =       ipip6_rcv,
1772         .err_handler    =       ipip6_err,
1773         .priority       =       1,
1774 };
1775
1776 static struct xfrm_tunnel ipip_handler __read_mostly = {
1777         .handler        =       ipip_rcv,
1778         .err_handler    =       ipip6_err,
1779         .priority       =       2,
1780 };
1781
1782 static void __net_exit sit_destroy_tunnels(struct net *net,
1783                                            struct list_head *head)
1784 {
1785         struct sit_net *sitn = net_generic(net, sit_net_id);
1786         struct net_device *dev, *aux;
1787         int prio;
1788
1789         for_each_netdev_safe(net, dev, aux)
1790                 if (dev->rtnl_link_ops == &sit_link_ops)
1791                         unregister_netdevice_queue(dev, head);
1792
1793         for (prio = 1; prio < 4; prio++) {
1794                 int h;
1795                 for (h = 0; h < HASH_SIZE; h++) {
1796                         struct ip_tunnel *t;
1797
1798                         t = rtnl_dereference(sitn->tunnels[prio][h]);
1799                         while (t != NULL) {
1800                                 /* If dev is in the same netns, it has already
1801                                  * been added to the list by the previous loop.
1802                                  */
1803                                 if (!net_eq(dev_net(t->dev), net))
1804                                         unregister_netdevice_queue(t->dev,
1805                                                                    head);
1806                                 t = rtnl_dereference(t->next);
1807                         }
1808                 }
1809         }
1810 }
1811
1812 static int __net_init sit_init_net(struct net *net)
1813 {
1814         struct sit_net *sitn = net_generic(net, sit_net_id);
1815         struct ip_tunnel *t;
1816         int err;
1817
1818         sitn->tunnels[0] = sitn->tunnels_wc;
1819         sitn->tunnels[1] = sitn->tunnels_l;
1820         sitn->tunnels[2] = sitn->tunnels_r;
1821         sitn->tunnels[3] = sitn->tunnels_r_l;
1822
1823         sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1824                                            NET_NAME_UNKNOWN,
1825                                            ipip6_tunnel_setup);
1826         if (!sitn->fb_tunnel_dev) {
1827                 err = -ENOMEM;
1828                 goto err_alloc_dev;
1829         }
1830         dev_net_set(sitn->fb_tunnel_dev, net);
1831         sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1832         /* FB netdevice is special: we have one, and only one per netns.
1833          * Allowing to move it to another netns is clearly unsafe.
1834          */
1835         sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1836
1837         err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1838         if (err)
1839                 goto err_dev_free;
1840
1841         ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1842
1843         if ((err = register_netdev(sitn->fb_tunnel_dev)))
1844                 goto err_reg_dev;
1845
1846         t = netdev_priv(sitn->fb_tunnel_dev);
1847
1848         strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1849         return 0;
1850
1851 err_reg_dev:
1852         dev_put(sitn->fb_tunnel_dev);
1853 err_dev_free:
1854         ipip6_dev_free(sitn->fb_tunnel_dev);
1855 err_alloc_dev:
1856         return err;
1857 }
1858
1859 static void __net_exit sit_exit_net(struct net *net)
1860 {
1861         LIST_HEAD(list);
1862
1863         rtnl_lock();
1864         sit_destroy_tunnels(net, &list);
1865         unregister_netdevice_many(&list);
1866         rtnl_unlock();
1867 }
1868
1869 static struct pernet_operations sit_net_ops = {
1870         .init = sit_init_net,
1871         .exit = sit_exit_net,
1872         .id   = &sit_net_id,
1873         .size = sizeof(struct sit_net),
1874 };
1875
1876 static void __exit sit_cleanup(void)
1877 {
1878         rtnl_link_unregister(&sit_link_ops);
1879         xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1880         xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1881
1882         unregister_pernet_device(&sit_net_ops);
1883         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1884 }
1885
1886 static int __init sit_init(void)
1887 {
1888         int err;
1889
1890         pr_info("IPv6 over IPv4 tunneling driver\n");
1891
1892         err = register_pernet_device(&sit_net_ops);
1893         if (err < 0)
1894                 return err;
1895         err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1896         if (err < 0) {
1897                 pr_info("%s: can't register ip6ip4\n", __func__);
1898                 goto xfrm_tunnel_failed;
1899         }
1900         err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1901         if (err < 0) {
1902                 pr_info("%s: can't register ip4ip4\n", __func__);
1903                 goto xfrm_tunnel4_failed;
1904         }
1905         err = rtnl_link_register(&sit_link_ops);
1906         if (err < 0)
1907                 goto rtnl_link_failed;
1908
1909 out:
1910         return err;
1911
1912 rtnl_link_failed:
1913         xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1914 xfrm_tunnel4_failed:
1915         xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1916 xfrm_tunnel_failed:
1917         unregister_pernet_device(&sit_net_ops);
1918         goto out;
1919 }
1920
1921 module_init(sit_init);
1922 module_exit(sit_cleanup);
1923 MODULE_LICENSE("GPL");
1924 MODULE_ALIAS_RTNL_LINK("sit");
1925 MODULE_ALIAS_NETDEV("sit0");