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 #include <linux/module.h>
  21 #include <linux/capability.h>
  22 #include <linux/errno.h>
  23 #include <linux/types.h>
  24 #include <linux/socket.h>
  25 #include <linux/sockios.h>
  26 #include <linux/net.h>
  27 #include <linux/in6.h>
  28 #include <linux/netdevice.h>
  29 #include <linux/if_arp.h>
  30 #include <linux/icmp.h>
  31 #include <linux/slab.h>
  32 #include <asm/uaccess.h>
  33 #include <linux/init.h>
  34 #include <linux/netfilter_ipv4.h>
  35 #include <linux/if_ether.h>
  36
  37 #include <net/sock.h>
  38 #include <net/snmp.h>
  39
  40 #include <net/ipv6.h>
  41 #include <net/protocol.h>
  42 #include <net/transp_v6.h>
  43 #include <net/ip6_fib.h>
  44 #include <net/ip6_route.h>
  45 #include <net/ndisc.h>
  46 #include <net/addrconf.h>
  47 #include <net/ip.h>
  48 #include <net/udp.h>
  49 #include <net/icmp.h>
  50 #include <net/ipip.h>
  51 #include <net/inet_ecn.h>
  52 #include <net/xfrm.h>
  53 #include <net/dsfield.h>
  54 #include <net/net_namespace.h>
  55 #include <net/netns/generic.h>
  56
  57 /*
  58    This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
  59
  60    For comments look at net/ipv4/ip_gre.c --ANK
  61  */
  62
  63 #define HASH_SIZE  16
  64 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
  65
  66 static int ipip6_tunnel_init(struct net_device *dev);
  67 static void ipip6_tunnel_setup(struct net_device *dev);
  68 static void ipip6_dev_free(struct net_device *dev);
  69
  70 static int sit_net_id __read_mostly;
  71 struct sit_net {
  72         struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE];
  73         struct ip_tunnel __rcu *tunnels_r[HASH_SIZE];
  74         struct ip_tunnel __rcu *tunnels_l[HASH_SIZE];
  75         struct ip_tunnel __rcu *tunnels_wc[1];
  76         struct ip_tunnel __rcu **tunnels[4];
  77
  78         struct net_device *fb_tunnel_dev;
  79 };
  80
  81 /*
  82  * Locking : hash tables are protected by RCU and RTNL
  83  */
  84
  85 #define for_each_ip_tunnel_rcu(start) \
  86         for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
  87
  88 /* often modified stats are per cpu, other are shared (netdev->stats) */
  89 struct pcpu_tstats {
  90         unsigned long   rx_packets;
  91         unsigned long   rx_bytes;
  92         unsigned long   tx_packets;
  93         unsigned long   tx_bytes;
  94 };
  95
  96 static struct net_device_stats *ipip6_get_stats(struct net_device *dev)
  97 {
  98         struct pcpu_tstats sum = { 0 };
  99         int i;
 100
 101         for_each_possible_cpu(i) {
 102                 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
 103
 104                 sum.rx_packets += tstats->rx_packets;
 105                 sum.rx_bytes   += tstats->rx_bytes;
 106                 sum.tx_packets += tstats->tx_packets;
 107                 sum.tx_bytes   += tstats->tx_bytes;
 108         }
 109         dev->stats.rx_packets = sum.rx_packets;
 110         dev->stats.rx_bytes   = sum.rx_bytes;
 111         dev->stats.tx_packets = sum.tx_packets;
 112         dev->stats.tx_bytes   = sum.tx_bytes;
 113         return &dev->stats;
 114 }
 115 /*
 116  * Must be invoked with rcu_read_lock
 117  */
 118 static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net,
 119                 struct net_device *dev, __be32 remote, __be32 local)
 120 {
 121         unsigned int h0 = HASH(remote);
 122         unsigned int h1 = HASH(local);
 123         struct ip_tunnel *t;
 124         struct sit_net *sitn = net_generic(net, sit_net_id);
 125
 126         for_each_ip_tunnel_rcu(sitn->tunnels_r_l[h0 ^ h1]) {
 127                 if (local == t->parms.iph.saddr &&
 128                     remote == t->parms.iph.daddr &&
 129                     (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
 130                     (t->dev->flags & IFF_UP))
 131                         return t;
 132         }
 133         for_each_ip_tunnel_rcu(sitn->tunnels_r[h0]) {
 134                 if (remote == t->parms.iph.daddr &&
 135                     (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
 136                     (t->dev->flags & IFF_UP))
 137                         return t;
 138         }
 139         for_each_ip_tunnel_rcu(sitn->tunnels_l[h1]) {
 140                 if (local == t->parms.iph.saddr &&
 141                     (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
 142                     (t->dev->flags & IFF_UP))
 143                         return t;
 144         }
 145         t = rcu_dereference(sitn->tunnels_wc[0]);
 146         if ((t != NULL) && (t->dev->flags & IFF_UP))
 147                 return t;
 148         return NULL;
 149 }
 150
 151 static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
 152                 struct ip_tunnel_parm *parms)
 153 {
 154         __be32 remote = parms->iph.daddr;
 155         __be32 local = parms->iph.saddr;
 156         unsigned int h = 0;
 157         int prio = 0;
 158
 159         if (remote) {
 160                 prio |= 2;
 161                 h ^= HASH(remote);
 162         }
 163         if (local) {
 164                 prio |= 1;
 165                 h ^= HASH(local);
 166         }
 167         return &sitn->tunnels[prio][h];
 168 }
 169
 170 static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
 171                 struct ip_tunnel *t)
 172 {
 173         return __ipip6_bucket(sitn, &t->parms);
 174 }
 175
 176 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
 177 {
 178         struct ip_tunnel __rcu **tp;
 179         struct ip_tunnel *iter;
 180
 181         for (tp = ipip6_bucket(sitn, t);
 182              (iter = rtnl_dereference(*tp)) != NULL;
 183              tp = &iter->next) {
 184                 if (t == iter) {
 185                         rcu_assign_pointer(*tp, t->next);
 186                         break;
 187                 }
 188         }
 189 }
 190
 191 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
 192 {
 193         struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
 194
 195         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 196         rcu_assign_pointer(*tp, t);
 197 }
 198
 199 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
 200 {
 201 #ifdef CONFIG_IPV6_SIT_6RD
 202         struct ip_tunnel *t = netdev_priv(dev);
 203
 204         if (t->dev == sitn->fb_tunnel_dev) {
 205                 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
 206                 t->ip6rd.relay_prefix = 0;
 207                 t->ip6rd.prefixlen = 16;
 208                 t->ip6rd.relay_prefixlen = 0;
 209         } else {
 210                 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
 211                 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
 212         }
 213 #endif
 214 }
 215
 216 static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
 217                 struct ip_tunnel_parm *parms, int create)
 218 {
 219         __be32 remote = parms->iph.daddr;
 220         __be32 local = parms->iph.saddr;
 221         struct ip_tunnel *t, *nt;
 222         struct ip_tunnel __rcu **tp;
 223         struct net_device *dev;
 224         char name[IFNAMSIZ];
 225         struct sit_net *sitn = net_generic(net, sit_net_id);
 226
 227         for (tp = __ipip6_bucket(sitn, parms);
 228             (t = rtnl_dereference(*tp)) != NULL;
 229              tp = &t->next) {
 230                 if (local == t->parms.iph.saddr &&
 231                     remote == t->parms.iph.daddr &&
 232                     parms->link == t->parms.link) {
 233                         if (create)
 234                                 return NULL;
 235                         else
 236                                 return t;
 237                 }
 238         }
 239         if (!create)
 240                 goto failed;
 241
 242         if (parms->name[0])
 243                 strlcpy(name, parms->name, IFNAMSIZ);
 244         else
 245                 strcpy(name, "sit%d");
 246
 247         dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup);
 248         if (dev == NULL)
 249                 return NULL;
 250
 251         dev_net_set(dev, net);
 252
 253         if (strchr(name, '%')) {
 254                 if (dev_alloc_name(dev, name) < 0)
 255                         goto failed_free;
 256         }
 257
 258         nt = netdev_priv(dev);
 259
 260         nt->parms = *parms;
 261         if (ipip6_tunnel_init(dev) < 0)
 262                 goto failed_free;
 263         ipip6_tunnel_clone_6rd(dev, sitn);
 264
 265         if (parms->i_flags & SIT_ISATAP)
 266                 dev->priv_flags |= IFF_ISATAP;
 267
 268         if (register_netdevice(dev) < 0)
 269                 goto failed_free;
 270
 271         dev_hold(dev);
 272
 273         ipip6_tunnel_link(sitn, nt);
 274         return nt;
 275
 276 failed_free:
 277         ipip6_dev_free(dev);
 278 failed:
 279         return NULL;
 280 }
 281
 282 #define for_each_prl_rcu(start)                 \
 283         for (prl = rcu_dereference(start);      \
 284              prl;                               \
 285              prl = rcu_dereference(prl->next))
 286
 287 static struct ip_tunnel_prl_entry *
 288 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
 289 {
 290         struct ip_tunnel_prl_entry *prl;
 291
 292         for_each_prl_rcu(t->prl)
 293                 if (prl->addr == addr)
 294                         break;
 295         return prl;
 296
 297 }
 298
 299 static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
 300                                 struct ip_tunnel_prl __user *a)
 301 {
 302         struct ip_tunnel_prl kprl, *kp;
 303         struct ip_tunnel_prl_entry *prl;
 304         unsigned int cmax, c = 0, ca, len;
 305         int ret = 0;
 306
 307         if (copy_from_user(&kprl, a, sizeof(kprl)))
 308                 return -EFAULT;
 309         cmax = kprl.datalen / sizeof(kprl);
 310         if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
 311                 cmax = 1;
 312
 313         /* For simple GET or for root users,
 314          * we try harder to allocate.
 315          */
 316         kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
 317                 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
 318                 NULL;
 319
 320         rcu_read_lock();
 321
 322         ca = t->prl_count < cmax ? t->prl_count : cmax;
 323
 324         if (!kp) {
 325                 /* We don't try hard to allocate much memory for
 326                  * non-root users.
 327                  * For root users, retry allocating enough memory for
 328                  * the answer.
 329                  */
 330                 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
 331                 if (!kp) {
 332                         ret = -ENOMEM;
 333                         goto out;
 334                 }
 335         }
 336
 337         c = 0;
 338         for_each_prl_rcu(t->prl) {
 339                 if (c >= cmax)
 340                         break;
 341                 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
 342                         continue;
 343                 kp[c].addr = prl->addr;
 344                 kp[c].flags = prl->flags;
 345                 c++;
 346                 if (kprl.addr != htonl(INADDR_ANY))
 347                         break;
 348         }
 349 out:
 350         rcu_read_unlock();
 351
 352         len = sizeof(*kp) * c;
 353         ret = 0;
 354         if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
 355                 ret = -EFAULT;
 356
 357         kfree(kp);
 358
 359         return ret;
 360 }
 361
 362 static int
 363 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
 364 {
 365         struct ip_tunnel_prl_entry *p;
 366         int err = 0;
 367
 368         if (a->addr == htonl(INADDR_ANY))
 369                 return -EINVAL;
 370
 371         ASSERT_RTNL();
 372
 373         for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
 374                 if (p->addr == a->addr) {
 375                         if (chg) {
 376                                 p->flags = a->flags;
 377                                 goto out;
 378                         }
 379                         err = -EEXIST;
 380                         goto out;
 381                 }
 382         }
 383
 384         if (chg) {
 385                 err = -ENXIO;
 386                 goto out;
 387         }
 388
 389         p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
 390         if (!p) {
 391                 err = -ENOBUFS;
 392                 goto out;
 393         }
 394
 395         p->next = t->prl;
 396         p->addr = a->addr;
 397         p->flags = a->flags;
 398         t->prl_count++;
 399         rcu_assign_pointer(t->prl, p);
 400 out:
 401         return err;
 402 }
 403
 404 static void prl_list_destroy_rcu(struct rcu_head *head)
 405 {
 406         struct ip_tunnel_prl_entry *p, *n;
 407
 408         p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
 409         do {
 410                 n = rcu_dereference_protected(p->next, 1);
 411                 kfree(p);
 412                 p = n;
 413         } while (p);
 414 }
 415
 416 static int
 417 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
 418 {
 419         struct ip_tunnel_prl_entry *x;
 420         struct ip_tunnel_prl_entry __rcu **p;
 421         int err = 0;
 422
 423         ASSERT_RTNL();
 424
 425         if (a && a->addr != htonl(INADDR_ANY)) {
 426                 for (p = &t->prl;
 427                      (x = rtnl_dereference(*p)) != NULL;
 428                      p = &x->next) {
 429                         if (x->addr == a->addr) {
 430                                 *p = x->next;
 431                                 kfree_rcu(x, rcu_head);
 432                                 t->prl_count--;
 433                                 goto out;
 434                         }
 435                 }
 436                 err = -ENXIO;
 437         } else {
 438                 x = rtnl_dereference(t->prl);
 439                 if (x) {
 440                         t->prl_count = 0;
 441                         call_rcu(&x->rcu_head, prl_list_destroy_rcu);
 442                         t->prl = NULL;
 443                 }
 444         }
 445 out:
 446         return err;
 447 }
 448
 449 static int
 450 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t)
 451 {
 452         struct ip_tunnel_prl_entry *p;
 453         int ok = 1;
 454
 455         rcu_read_lock();
 456         p = __ipip6_tunnel_locate_prl(t, iph->saddr);
 457         if (p) {
 458                 if (p->flags & PRL_DEFAULT)
 459                         skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
 460                 else
 461                         skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
 462         } else {
 463                 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
 464                 if (ipv6_addr_is_isatap(addr6) &&
 465                     (addr6->s6_addr32[3] == iph->saddr) &&
 466                     ipv6_chk_prefix(addr6, t->dev))
 467                         skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
 468                 else
 469                         ok = 0;
 470         }
 471         rcu_read_unlock();
 472         return ok;
 473 }
 474
 475 static void ipip6_tunnel_uninit(struct net_device *dev)
 476 {
 477         struct net *net = dev_net(dev);
 478         struct sit_net *sitn = net_generic(net, sit_net_id);
 479
 480         if (dev == sitn->fb_tunnel_dev) {
 481                 rcu_assign_pointer(sitn->tunnels_wc[0], NULL);
 482         } else {
 483                 ipip6_tunnel_unlink(sitn, netdev_priv(dev));
 484                 ipip6_tunnel_del_prl(netdev_priv(dev), NULL);
 485         }
 486         dev_put(dev);
 487 }
 488
 489
 490 static int ipip6_err(struct sk_buff *skb, u32 info)
 491 {
 492
 493 /* All the routers (except for Linux) return only
 494    8 bytes of packet payload. It means, that precise relaying of
 495    ICMP in the real Internet is absolutely infeasible.
 496  */
 497         struct iphdr *iph = (struct iphdr*)skb->data;
 498         const int type = icmp_hdr(skb)->type;
 499         const int code = icmp_hdr(skb)->code;
 500         struct ip_tunnel *t;
 501         int err;
 502
 503         switch (type) {
 504         default:
 505         case ICMP_PARAMETERPROB:
 506                 return 0;
 507
 508         case ICMP_DEST_UNREACH:
 509                 switch (code) {
 510                 case ICMP_SR_FAILED:
 511                 case ICMP_PORT_UNREACH:
 512                         /* Impossible event. */
 513                         return 0;
 514                 case ICMP_FRAG_NEEDED:
 515                         /* Soft state for pmtu is maintained by IP core. */
 516                         return 0;
 517                 default:
 518                         /* All others are translated to HOST_UNREACH.
 519                            rfc2003 contains "deep thoughts" about NET_UNREACH,
 520                            I believe they are just ether pollution. --ANK
 521                          */
 522                         break;
 523                 }
 524                 break;
 525         case ICMP_TIME_EXCEEDED:
 526                 if (code != ICMP_EXC_TTL)
 527                         return 0;
 528                 break;
 529         }
 530
 531         err = -ENOENT;
 532
 533         rcu_read_lock();
 534         t = ipip6_tunnel_lookup(dev_net(skb->dev),
 535                                 skb->dev,
 536                                 iph->daddr,
 537                                 iph->saddr);
 538         if (t == NULL || t->parms.iph.daddr == 0)
 539                 goto out;
 540
 541         err = 0;
 542         if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
 543                 goto out;
 544
 545         if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
 546                 t->err_count++;
 547         else
 548                 t->err_count = 1;
 549         t->err_time = jiffies;
 550 out:
 551         rcu_read_unlock();
 552         return err;
 553 }
 554
 555 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
 556 {
 557         if (INET_ECN_is_ce(iph->tos))
 558                 IP6_ECN_set_ce(ipv6_hdr(skb));
 559 }
 560
 561 static int ipip6_rcv(struct sk_buff *skb)
 562 {
 563         struct iphdr *iph;
 564         struct ip_tunnel *tunnel;
 565
 566         if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 567                 goto out;
 568
 569         iph = ip_hdr(skb);
 570
 571         rcu_read_lock();
 572         tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 573                                      iph->saddr, iph->daddr);
 574         if (tunnel != NULL) {
 575                 struct pcpu_tstats *tstats;
 576
 577                 secpath_reset(skb);
 578                 skb->mac_header = skb->network_header;
 579                 skb_reset_network_header(skb);
 580                 IPCB(skb)->flags = 0;
 581                 skb->protocol = htons(ETH_P_IPV6);
 582                 skb->pkt_type = PACKET_HOST;
 583
 584                 if ((tunnel->dev->priv_flags & IFF_ISATAP) &&
 585                     !isatap_chksrc(skb, iph, tunnel)) {
 586                         tunnel->dev->stats.rx_errors++;
 587                         rcu_read_unlock();
 588                         kfree_skb(skb);
 589                         return 0;
 590                 }
 591
 592                 tstats = this_cpu_ptr(tunnel->dev->tstats);
 593                 tstats->rx_packets++;
 594                 tstats->rx_bytes += skb->len;
 595
 596                 __skb_tunnel_rx(skb, tunnel->dev);
 597
 598                 ipip6_ecn_decapsulate(iph, skb);
 599
 600                 netif_rx(skb);
 601
 602                 rcu_read_unlock();
 603                 return 0;
 604         }
 605
 606         /* no tunnel matched,  let upstream know, ipsec may handle it */
 607         rcu_read_unlock();
 608         return 1;
 609 out:
 610         kfree_skb(skb);
 611         return 0;
 612 }
 613
 614 /*
 615  * Returns the embedded IPv4 address if the IPv6 address
 616  * comes from 6rd / 6to4 (RFC 3056) addr space.
 617  */
 618 static inline
 619 __be32 try_6rd(struct in6_addr *v6dst, struct ip_tunnel *tunnel)
 620 {
 621         __be32 dst = 0;
 622
 623 #ifdef CONFIG_IPV6_SIT_6RD
 624         if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
 625                               tunnel->ip6rd.prefixlen)) {
 626                 unsigned int pbw0, pbi0;
 627                 int pbi1;
 628                 u32 d;
 629
 630                 pbw0 = tunnel->ip6rd.prefixlen >> 5;
 631                 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
 632
 633                 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
 634                     tunnel->ip6rd.relay_prefixlen;
 635
 636                 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
 637                 if (pbi1 > 0)
 638                         d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
 639                              (32 - pbi1);
 640
 641                 dst = tunnel->ip6rd.relay_prefix | htonl(d);
 642         }
 643 #else
 644         if (v6dst->s6_addr16[0] == htons(0x2002)) {
 645                 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
 646                 memcpy(&dst, &v6dst->s6_addr16[1], 4);
 647         }
 648 #endif
 649         return dst;
 650 }
 651
 652 /*
 653  *      This function assumes it is being called from dev_queue_xmit()
 654  *      and that skb is filled properly by that function.
 655  */
 656
 657 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 658                                      struct net_device *dev)
 659 {
 660         struct ip_tunnel *tunnel = netdev_priv(dev);
 661         struct pcpu_tstats *tstats;
 662         struct iphdr  *tiph = &tunnel->parms.iph;
 663         struct ipv6hdr *iph6 = ipv6_hdr(skb);
 664         u8     tos = tunnel->parms.iph.tos;
 665         __be16 df = tiph->frag_off;
 666         struct rtable *rt;                      /* Route to the other host */
 667         struct net_device *tdev;                /* Device to other host */
 668         struct iphdr  *iph;                     /* Our new IP header */
 669         unsigned int max_headroom;              /* The extra header space needed */
 670         __be32 dst = tiph->daddr;
 671         int    mtu;
 672         struct in6_addr *addr6;
 673         int addr_type;
 674
 675         if (skb->protocol != htons(ETH_P_IPV6))
 676                 goto tx_error;
 677
 678         /* ISATAP (RFC4214) - must come before 6to4 */
 679         if (dev->priv_flags & IFF_ISATAP) {
 680                 struct neighbour *neigh = NULL;
 681
 682                 if (skb_dst(skb))
 683                         neigh = skb_dst(skb)->neighbour;
 684
 685                 if (neigh == NULL) {
 686                         if (net_ratelimit())
 687                                 printk(KERN_DEBUG "sit: nexthop == NULL\n");
 688                         goto tx_error;
 689                 }
 690
 691                 addr6 = (struct in6_addr*)&neigh->primary_key;
 692                 addr_type = ipv6_addr_type(addr6);
 693
 694                 if ((addr_type & IPV6_ADDR_UNICAST) &&
 695                      ipv6_addr_is_isatap(addr6))
 696                         dst = addr6->s6_addr32[3];
 697                 else
 698                         goto tx_error;
 699         }
 700
 701         if (!dst)
 702                 dst = try_6rd(&iph6->daddr, tunnel);
 703
 704         if (!dst) {
 705                 struct neighbour *neigh = NULL;
 706
 707                 if (skb_dst(skb))
 708                         neigh = skb_dst(skb)->neighbour;
 709
 710                 if (neigh == NULL) {
 711                         if (net_ratelimit())
 712                                 printk(KERN_DEBUG "sit: nexthop == NULL\n");
 713                         goto tx_error;
 714                 }
 715
 716                 addr6 = (struct in6_addr*)&neigh->primary_key;
 717                 addr_type = ipv6_addr_type(addr6);
 718
 719                 if (addr_type == IPV6_ADDR_ANY) {
 720                         addr6 = &ipv6_hdr(skb)->daddr;
 721                         addr_type = ipv6_addr_type(addr6);
 722                 }
 723
 724                 if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
 725                         goto tx_error_icmp;
 726
 727                 dst = addr6->s6_addr32[3];
 728         }
 729
 730         rt = ip_route_output_ports(dev_net(dev), NULL,
 731                                    dst, tiph->saddr,
 732                                    0, 0,
 733                                    IPPROTO_IPV6, RT_TOS(tos),
 734                                    tunnel->parms.link);
 735         if (IS_ERR(rt)) {
 736                 dev->stats.tx_carrier_errors++;
 737                 goto tx_error_icmp;
 738         }
 739         if (rt->rt_type != RTN_UNICAST) {
 740                 ip_rt_put(rt);
 741                 dev->stats.tx_carrier_errors++;
 742                 goto tx_error_icmp;
 743         }
 744         tdev = rt->dst.dev;
 745
 746         if (tdev == dev) {
 747                 ip_rt_put(rt);
 748                 dev->stats.collisions++;
 749                 goto tx_error;
 750         }
 751
 752         if (df) {
 753                 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
 754
 755                 if (mtu < 68) {
 756                         dev->stats.collisions++;
 757                         ip_rt_put(rt);
 758                         goto tx_error;
 759                 }
 760
 761                 if (mtu < IPV6_MIN_MTU) {
 762                         mtu = IPV6_MIN_MTU;
 763                         df = 0;
 764                 }
 765
 766                 if (tunnel->parms.iph.daddr && skb_dst(skb))
 767                         skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
 768
 769                 if (skb->len > mtu) {
 770                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 771                         ip_rt_put(rt);
 772                         goto tx_error;
 773                 }
 774         }
 775
 776         if (tunnel->err_count > 0) {
 777                 if (time_before(jiffies,
 778                                 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
 779                         tunnel->err_count--;
 780                         dst_link_failure(skb);
 781                 } else
 782                         tunnel->err_count = 0;
 783         }
 784
 785         /*
 786          * Okay, now see if we can stuff it in the buffer as-is.
 787          */
 788         max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
 789
 790         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 791             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 792                 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
 793                 if (!new_skb) {
 794                         ip_rt_put(rt);
 795                         dev->stats.tx_dropped++;
 796                         dev_kfree_skb(skb);
 797                         return NETDEV_TX_OK;
 798                 }
 799                 if (skb->sk)
 800                         skb_set_owner_w(new_skb, skb->sk);
 801                 dev_kfree_skb(skb);
 802                 skb = new_skb;
 803                 iph6 = ipv6_hdr(skb);
 804         }
 805
 806         skb->transport_header = skb->network_header;
 807         skb_push(skb, sizeof(struct iphdr));
 808         skb_reset_network_header(skb);
 809         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 810         IPCB(skb)->flags = 0;
 811         skb_dst_drop(skb);
 812         skb_dst_set(skb, &rt->dst);
 813
 814         /*
 815          *      Push down and install the IPIP header.
 816          */
 817
 818         iph                     =       ip_hdr(skb);
 819         iph->version            =       4;
 820         iph->ihl                =       sizeof(struct iphdr)>>2;
 821         iph->frag_off           =       df;
 822         iph->protocol           =       IPPROTO_IPV6;
 823         iph->tos                =       INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
 824         iph->daddr              =       rt->rt_dst;
 825         iph->saddr              =       rt->rt_src;
 826
 827         if ((iph->ttl = tiph->ttl) == 0)
 828                 iph->ttl        =       iph6->hop_limit;
 829
 830         nf_reset(skb);
 831         tstats = this_cpu_ptr(dev->tstats);
 832         __IPTUNNEL_XMIT(tstats, &dev->stats);
 833         return NETDEV_TX_OK;
 834
 835 tx_error_icmp:
 836         dst_link_failure(skb);
 837 tx_error:
 838         dev->stats.tx_errors++;
 839         dev_kfree_skb(skb);
 840         return NETDEV_TX_OK;
 841 }
 842
 843 static void ipip6_tunnel_bind_dev(struct net_device *dev)
 844 {
 845         struct net_device *tdev = NULL;
 846         struct ip_tunnel *tunnel;
 847         struct iphdr *iph;
 848
 849         tunnel = netdev_priv(dev);
 850         iph = &tunnel->parms.iph;
 851
 852         if (iph->daddr) {
 853                 struct rtable *rt = ip_route_output_ports(dev_net(dev), NULL,
 854                                                           iph->daddr, iph->saddr,
 855                                                           0, 0,
 856                                                           IPPROTO_IPV6,
 857                                                           RT_TOS(iph->tos),
 858                                                           tunnel->parms.link);
 859
 860                 if (!IS_ERR(rt)) {
 861                         tdev = rt->dst.dev;
 862                         ip_rt_put(rt);
 863                 }
 864                 dev->flags |= IFF_POINTOPOINT;
 865         }
 866
 867         if (!tdev && tunnel->parms.link)
 868                 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
 869
 870         if (tdev) {
 871                 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
 872                 dev->mtu = tdev->mtu - sizeof(struct iphdr);
 873                 if (dev->mtu < IPV6_MIN_MTU)
 874                         dev->mtu = IPV6_MIN_MTU;
 875         }
 876         dev->iflink = tunnel->parms.link;
 877 }
 878
 879 static int
 880 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
 881 {
 882         int err = 0;
 883         struct ip_tunnel_parm p;
 884         struct ip_tunnel_prl prl;
 885         struct ip_tunnel *t;
 886         struct net *net = dev_net(dev);
 887         struct sit_net *sitn = net_generic(net, sit_net_id);
 888 #ifdef CONFIG_IPV6_SIT_6RD
 889         struct ip_tunnel_6rd ip6rd;
 890 #endif
 891
 892         switch (cmd) {
 893         case SIOCGETTUNNEL:
 894 #ifdef CONFIG_IPV6_SIT_6RD
 895         case SIOCGET6RD:
 896 #endif
 897                 t = NULL;
 898                 if (dev == sitn->fb_tunnel_dev) {
 899                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
 900                                 err = -EFAULT;
 901                                 break;
 902                         }
 903                         t = ipip6_tunnel_locate(net, &p, 0);
 904                 }
 905                 if (t == NULL)
 906                         t = netdev_priv(dev);
 907
 908                 err = -EFAULT;
 909                 if (cmd == SIOCGETTUNNEL) {
 910                         memcpy(&p, &t->parms, sizeof(p));
 911                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
 912                                          sizeof(p)))
 913                                 goto done;
 914 #ifdef CONFIG_IPV6_SIT_6RD
 915                 } else {
 916                         ipv6_addr_copy(&ip6rd.prefix, &t->ip6rd.prefix);
 917                         ip6rd.relay_prefix = t->ip6rd.relay_prefix;
 918                         ip6rd.prefixlen = t->ip6rd.prefixlen;
 919                         ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
 920                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
 921                                          sizeof(ip6rd)))
 922                                 goto done;
 923 #endif
 924                 }
 925                 err = 0;
 926                 break;
 927
 928         case SIOCADDTUNNEL:
 929         case SIOCCHGTUNNEL:
 930                 err = -EPERM;
 931                 if (!capable(CAP_NET_ADMIN))
 932                         goto done;
 933
 934                 err = -EFAULT;
 935                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 936                         goto done;
 937
 938                 err = -EINVAL;
 939                 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
 940                     p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
 941                         goto done;
 942                 if (p.iph.ttl)
 943                         p.iph.frag_off |= htons(IP_DF);
 944
 945                 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
 946
 947                 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
 948                         if (t != NULL) {
 949                                 if (t->dev != dev) {
 950                                         err = -EEXIST;
 951                                         break;
 952                                 }
 953                         } else {
 954                                 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
 955                                     (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
 956                                         err = -EINVAL;
 957                                         break;
 958                                 }
 959                                 t = netdev_priv(dev);
 960                                 ipip6_tunnel_unlink(sitn, t);
 961                                 synchronize_net();
 962                                 t->parms.iph.saddr = p.iph.saddr;
 963                                 t->parms.iph.daddr = p.iph.daddr;
 964                                 memcpy(dev->dev_addr, &p.iph.saddr, 4);
 965                                 memcpy(dev->broadcast, &p.iph.daddr, 4);
 966                                 ipip6_tunnel_link(sitn, t);
 967                                 netdev_state_change(dev);
 968                         }
 969                 }
 970
 971                 if (t) {
 972                         err = 0;
 973                         if (cmd == SIOCCHGTUNNEL) {
 974                                 t->parms.iph.ttl = p.iph.ttl;
 975                                 t->parms.iph.tos = p.iph.tos;
 976                                 if (t->parms.link != p.link) {
 977                                         t->parms.link = p.link;
 978                                         ipip6_tunnel_bind_dev(dev);
 979                                         netdev_state_change(dev);
 980                                 }
 981                         }
 982                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
 983                                 err = -EFAULT;
 984                 } else
 985                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
 986                 break;
 987
 988         case SIOCDELTUNNEL:
 989                 err = -EPERM;
 990                 if (!capable(CAP_NET_ADMIN))
 991                         goto done;
 992
 993                 if (dev == sitn->fb_tunnel_dev) {
 994                         err = -EFAULT;
 995                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 996                                 goto done;
 997                         err = -ENOENT;
 998                         if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
 999                                 goto done;
1000                         err = -EPERM;
1001                         if (t == netdev_priv(sitn->fb_tunnel_dev))
1002                                 goto done;
1003                         dev = t->dev;
1004                 }
1005                 unregister_netdevice(dev);
1006                 err = 0;
1007                 break;
1008
1009         case SIOCGETPRL:
1010                 err = -EINVAL;
1011                 if (dev == sitn->fb_tunnel_dev)
1012                         goto done;
1013                 err = -ENOENT;
1014                 if (!(t = netdev_priv(dev)))
1015                         goto done;
1016                 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1017                 break;
1018
1019         case SIOCADDPRL:
1020         case SIOCDELPRL:
1021         case SIOCCHGPRL:
1022                 err = -EPERM;
1023                 if (!capable(CAP_NET_ADMIN))
1024                         goto done;
1025                 err = -EINVAL;
1026                 if (dev == sitn->fb_tunnel_dev)
1027                         goto done;
1028                 err = -EFAULT;
1029                 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1030                         goto done;
1031                 err = -ENOENT;
1032                 if (!(t = netdev_priv(dev)))
1033                         goto done;
1034
1035                 switch (cmd) {
1036                 case SIOCDELPRL:
1037                         err = ipip6_tunnel_del_prl(t, &prl);
1038                         break;
1039                 case SIOCADDPRL:
1040                 case SIOCCHGPRL:
1041                         err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1042                         break;
1043                 }
1044                 netdev_state_change(dev);
1045                 break;
1046
1047 #ifdef CONFIG_IPV6_SIT_6RD
1048         case SIOCADD6RD:
1049         case SIOCCHG6RD:
1050         case SIOCDEL6RD:
1051                 err = -EPERM;
1052                 if (!capable(CAP_NET_ADMIN))
1053                         goto done;
1054
1055                 err = -EFAULT;
1056                 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1057                                    sizeof(ip6rd)))
1058                         goto done;
1059
1060                 t = netdev_priv(dev);
1061
1062                 if (cmd != SIOCDEL6RD) {
1063                         struct in6_addr prefix;
1064                         __be32 relay_prefix;
1065
1066                         err = -EINVAL;
1067                         if (ip6rd.relay_prefixlen > 32 ||
1068                             ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64)
1069                                 goto done;
1070
1071                         ipv6_addr_prefix(&prefix, &ip6rd.prefix,
1072                                          ip6rd.prefixlen);
1073                         if (!ipv6_addr_equal(&prefix, &ip6rd.prefix))
1074                                 goto done;
1075                         if (ip6rd.relay_prefixlen)
1076                                 relay_prefix = ip6rd.relay_prefix &
1077                                                htonl(0xffffffffUL <<
1078                                                      (32 - ip6rd.relay_prefixlen));
1079                         else
1080                                 relay_prefix = 0;
1081                         if (relay_prefix != ip6rd.relay_prefix)
1082                                 goto done;
1083
1084                         ipv6_addr_copy(&t->ip6rd.prefix, &prefix);
1085                         t->ip6rd.relay_prefix = relay_prefix;
1086                         t->ip6rd.prefixlen = ip6rd.prefixlen;
1087                         t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen;
1088                 } else
1089                         ipip6_tunnel_clone_6rd(dev, sitn);
1090
1091                 err = 0;
1092                 break;
1093 #endif
1094
1095         default:
1096                 err = -EINVAL;
1097         }
1098
1099 done:
1100         return err;
1101 }
1102
1103 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1104 {
1105         if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1106                 return -EINVAL;
1107         dev->mtu = new_mtu;
1108         return 0;
1109 }
1110
1111 static const struct net_device_ops ipip6_netdev_ops = {
1112         .ndo_uninit     = ipip6_tunnel_uninit,
1113         .ndo_start_xmit = ipip6_tunnel_xmit,
1114         .ndo_do_ioctl   = ipip6_tunnel_ioctl,
1115         .ndo_change_mtu = ipip6_tunnel_change_mtu,
1116         .ndo_get_stats  = ipip6_get_stats,
1117 };
1118
1119 static void ipip6_dev_free(struct net_device *dev)
1120 {
1121         free_percpu(dev->tstats);
1122         free_netdev(dev);
1123 }
1124
1125 static void ipip6_tunnel_setup(struct net_device *dev)
1126 {
1127         dev->netdev_ops         = &ipip6_netdev_ops;
1128         dev->destructor         = ipip6_dev_free;
1129
1130         dev->type               = ARPHRD_SIT;
1131         dev->hard_header_len    = LL_MAX_HEADER + sizeof(struct iphdr);
1132         dev->mtu                = ETH_DATA_LEN - sizeof(struct iphdr);
1133         dev->flags              = IFF_NOARP;
1134         dev->priv_flags        &= ~IFF_XMIT_DST_RELEASE;
1135         dev->iflink             = 0;
1136         dev->addr_len           = 4;
1137         dev->features           |= NETIF_F_NETNS_LOCAL;
1138         dev->features           |= NETIF_F_LLTX;
1139 }
1140
1141 static int ipip6_tunnel_init(struct net_device *dev)
1142 {
1143         struct ip_tunnel *tunnel = netdev_priv(dev);
1144
1145         tunnel->dev = dev;
1146         strcpy(tunnel->parms.name, dev->name);
1147
1148         memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1149         memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1150
1151         ipip6_tunnel_bind_dev(dev);
1152         dev->tstats = alloc_percpu(struct pcpu_tstats);
1153         if (!dev->tstats)
1154                 return -ENOMEM;
1155
1156         return 0;
1157 }
1158
1159 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1160 {
1161         struct ip_tunnel *tunnel = netdev_priv(dev);
1162         struct iphdr *iph = &tunnel->parms.iph;
1163         struct net *net = dev_net(dev);
1164         struct sit_net *sitn = net_generic(net, sit_net_id);
1165
1166         tunnel->dev = dev;
1167         strcpy(tunnel->parms.name, dev->name);
1168
1169         iph->version            = 4;
1170         iph->protocol           = IPPROTO_IPV6;
1171         iph->ihl                = 5;
1172         iph->ttl                = 64;
1173
1174         dev->tstats = alloc_percpu(struct pcpu_tstats);
1175         if (!dev->tstats)
1176                 return -ENOMEM;
1177         dev_hold(dev);
1178         rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1179         return 0;
1180 }
1181
1182 static struct xfrm_tunnel sit_handler __read_mostly = {
1183         .handler        =       ipip6_rcv,
1184         .err_handler    =       ipip6_err,
1185         .priority       =       1,
1186 };
1187
1188 static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head)
1189 {
1190         int prio;
1191
1192         for (prio = 1; prio < 4; prio++) {
1193                 int h;
1194                 for (h = 0; h < HASH_SIZE; h++) {
1195                         struct ip_tunnel *t;
1196
1197                         t = rtnl_dereference(sitn->tunnels[prio][h]);
1198                         while (t != NULL) {
1199                                 unregister_netdevice_queue(t->dev, head);
1200                                 t = rtnl_dereference(t->next);
1201                         }
1202                 }
1203         }
1204 }
1205
1206 static int __net_init sit_init_net(struct net *net)
1207 {
1208         struct sit_net *sitn = net_generic(net, sit_net_id);
1209         int err;
1210
1211         sitn->tunnels[0] = sitn->tunnels_wc;
1212         sitn->tunnels[1] = sitn->tunnels_l;
1213         sitn->tunnels[2] = sitn->tunnels_r;
1214         sitn->tunnels[3] = sitn->tunnels_r_l;
1215
1216         sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1217                                            ipip6_tunnel_setup);
1218         if (!sitn->fb_tunnel_dev) {
1219                 err = -ENOMEM;
1220                 goto err_alloc_dev;
1221         }
1222         dev_net_set(sitn->fb_tunnel_dev, net);
1223
1224         err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1225         if (err)
1226                 goto err_dev_free;
1227
1228         ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1229
1230         if ((err = register_netdev(sitn->fb_tunnel_dev)))
1231                 goto err_reg_dev;
1232
1233         return 0;
1234
1235 err_reg_dev:
1236         dev_put(sitn->fb_tunnel_dev);
1237 err_dev_free:
1238         ipip6_dev_free(sitn->fb_tunnel_dev);
1239 err_alloc_dev:
1240         return err;
1241 }
1242
1243 static void __net_exit sit_exit_net(struct net *net)
1244 {
1245         struct sit_net *sitn = net_generic(net, sit_net_id);
1246         LIST_HEAD(list);
1247
1248         rtnl_lock();
1249         sit_destroy_tunnels(sitn, &list);
1250         unregister_netdevice_queue(sitn->fb_tunnel_dev, &list);
1251         unregister_netdevice_many(&list);
1252         rtnl_unlock();
1253 }
1254
1255 static struct pernet_operations sit_net_ops = {
1256         .init = sit_init_net,
1257         .exit = sit_exit_net,
1258         .id   = &sit_net_id,
1259         .size = sizeof(struct sit_net),
1260 };
1261
1262 static void __exit sit_cleanup(void)
1263 {
1264         xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1265
1266         unregister_pernet_device(&sit_net_ops);
1267         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1268 }
1269
1270 static int __init sit_init(void)
1271 {
1272         int err;
1273
1274         printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
1275
1276         err = register_pernet_device(&sit_net_ops);
1277         if (err < 0)
1278                 return err;
1279         err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1280         if (err < 0) {
1281                 unregister_pernet_device(&sit_net_ops);
1282                 printk(KERN_INFO "sit init: Can't add protocol\n");
1283         }
1284         return err;
1285 }
1286
1287 module_init(sit_init);
1288 module_exit(sit_cleanup);
1289 MODULE_LICENSE("GPL");
1290 MODULE_ALIAS_NETDEV("sit0");