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 <linux/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 IP6_SIT_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 unsigned int sit_net_id __read_mostly;
  80 struct sit_net {
  81         struct ip_tunnel __rcu *tunnels_r_l[IP6_SIT_HASH_SIZE];
  82         struct ip_tunnel __rcu *tunnels_r[IP6_SIT_HASH_SIZE];
  83         struct ip_tunnel __rcu *tunnels_l[IP6_SIT_HASH_SIZE];
  84         struct ip_tunnel __rcu *tunnels_wc[1];
  85         struct ip_tunnel __rcu **tunnels[4];
  86
  87         struct net_device *fb_tunnel_dev;
  88 };
  89
  90 /*
  91  * Must be invoked with rcu_read_lock
  92  */
  93 static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
  94                 struct net_device *dev, __be32 remote, __be32 local)
  95 {
  96         unsigned int h0 = HASH(remote);
  97         unsigned int h1 = HASH(local);
  98         struct ip_tunnel *t;
  99         struct sit_net *sitn = net_generic(net, sit_net_id);
 100
 101         for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
 102                 if (local == t->parms.iph.saddr &&
 103                     remote == t->parms.iph.daddr &&
 104                     (!dev || !t->parms.link || dev->ifindex == t->parms.link) &&
 105                     (t->dev->flags & IFF_UP))
 106                         return t;
 107         }
 108         for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) {
 109                 if (remote == t->parms.iph.daddr &&
 110                     (!dev || !t->parms.link || dev->ifindex == t->parms.link) &&
 111                     (t->dev->flags & IFF_UP))
 112                         return t;
 113         }
 114         for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
 115                 if (local == t->parms.iph.saddr &&
 116                     (!dev || !t->parms.link || dev->ifindex == t->parms.link) &&
 117                     (t->dev->flags & IFF_UP))
 118                         return t;
 119         }
 120         t = rcu_dereference(sitn->tunnels_wc[0]);
 121         if (t && (t->dev->flags & IFF_UP))
 122                 return t;
 123         return NULL;
 124 }
 125
 126 static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
 127                 struct ip_tunnel_parm *parms)
 128 {
 129         __be32 remote = parms->iph.daddr;
 130         __be32 local = parms->iph.saddr;
 131         unsigned int h = 0;
 132         int prio = 0;
 133
 134         if (remote) {
 135                 prio |= 2;
 136                 h ^= HASH(remote);
 137         }
 138         if (local) {
 139                 prio |= 1;
 140                 h ^= HASH(local);
 141         }
 142         return &sitn->tunnels[prio][h];
 143 }
 144
 145 static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
 146                 struct ip_tunnel *t)
 147 {
 148         return __ipip6_bucket(sitn, &t->parms);
 149 }
 150
 151 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
 152 {
 153         struct ip_tunnel __rcu **tp;
 154         struct ip_tunnel *iter;
 155
 156         for (tp = ipip6_bucket(sitn, t);
 157              (iter = rtnl_dereference(*tp)) != NULL;
 158              tp = &iter->next) {
 159                 if (t == iter) {
 160                         rcu_assign_pointer(*tp, t->next);
 161                         break;
 162                 }
 163         }
 164 }
 165
 166 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
 167 {
 168         struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
 169
 170         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 171         rcu_assign_pointer(*tp, t);
 172 }
 173
 174 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
 175 {
 176 #ifdef CONFIG_IPV6_SIT_6RD
 177         struct ip_tunnel *t = netdev_priv(dev);
 178
 179         if (dev == sitn->fb_tunnel_dev) {
 180                 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
 181                 t->ip6rd.relay_prefix = 0;
 182                 t->ip6rd.prefixlen = 16;
 183                 t->ip6rd.relay_prefixlen = 0;
 184         } else {
 185                 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
 186                 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
 187         }
 188 #endif
 189 }
 190
 191 static int ipip6_tunnel_create(struct net_device *dev)
 192 {
 193         struct ip_tunnel *t = netdev_priv(dev);
 194         struct net *net = dev_net(dev);
 195         struct sit_net *sitn = net_generic(net, sit_net_id);
 196         int err;
 197
 198         memcpy(dev->dev_addr, &t->parms.iph.saddr, 4);
 199         memcpy(dev->broadcast, &t->parms.iph.daddr, 4);
 200
 201         if ((__force u16)t->parms.i_flags & SIT_ISATAP)
 202                 dev->priv_flags |= IFF_ISATAP;
 203
 204         dev->rtnl_link_ops = &sit_link_ops;
 205
 206         err = register_netdevice(dev);
 207         if (err < 0)
 208                 goto out;
 209
 210         ipip6_tunnel_clone_6rd(dev, sitn);
 211
 212         dev_hold(dev);
 213
 214         ipip6_tunnel_link(sitn, t);
 215         return 0;
 216
 217 out:
 218         return err;
 219 }
 220
 221 static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
 222                 struct ip_tunnel_parm *parms, int create)
 223 {
 224         __be32 remote = parms->iph.daddr;
 225         __be32 local = parms->iph.saddr;
 226         struct ip_tunnel *t, *nt;
 227         struct ip_tunnel __rcu **tp;
 228         struct net_device *dev;
 229         char name[IFNAMSIZ];
 230         struct sit_net *sitn = net_generic(net, sit_net_id);
 231
 232         for (tp = __ipip6_bucket(sitn, parms);
 233             (t = rtnl_dereference(*tp)) != NULL;
 234              tp = &t->next) {
 235                 if (local == t->parms.iph.saddr &&
 236                     remote == t->parms.iph.daddr &&
 237                     parms->link == t->parms.link) {
 238                         if (create)
 239                                 return NULL;
 240                         else
 241                                 return t;
 242                 }
 243         }
 244         if (!create)
 245                 goto failed;
 246
 247         if (parms->name[0]) {
 248                 if (!dev_valid_name(parms->name))
 249                         goto failed;
 250                 strlcpy(name, parms->name, IFNAMSIZ);
 251         } else {
 252                 strcpy(name, "sit%d");
 253         }
 254         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 255                            ipip6_tunnel_setup);
 256         if (!dev)
 257                 return NULL;
 258
 259         dev_net_set(dev, net);
 260
 261         nt = netdev_priv(dev);
 262
 263         nt->parms = *parms;
 264         if (ipip6_tunnel_create(dev) < 0)
 265                 goto failed_free;
 266
 267         return nt;
 268
 269 failed_free:
 270         free_netdev(dev);
 271 failed:
 272         return NULL;
 273 }
 274
 275 #define for_each_prl_rcu(start)                 \
 276         for (prl = rcu_dereference(start);      \
 277              prl;                               \
 278              prl = rcu_dereference(prl->next))
 279
 280 static struct ip_tunnel_prl_entry *
 281 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
 282 {
 283         struct ip_tunnel_prl_entry *prl;
 284
 285         for_each_prl_rcu(t->prl)
 286                 if (prl->addr == addr)
 287                         break;
 288         return prl;
 289
 290 }
 291
 292 static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
 293                                 struct ip_tunnel_prl __user *a)
 294 {
 295         struct ip_tunnel_prl kprl, *kp;
 296         struct ip_tunnel_prl_entry *prl;
 297         unsigned int cmax, c = 0, ca, len;
 298         int ret = 0;
 299
 300         if (copy_from_user(&kprl, a, sizeof(kprl)))
 301                 return -EFAULT;
 302         cmax = kprl.datalen / sizeof(kprl);
 303         if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
 304                 cmax = 1;
 305
 306         /* For simple GET or for root users,
 307          * we try harder to allocate.
 308          */
 309         kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
 310                 kcalloc(cmax, sizeof(*kp), GFP_KERNEL | __GFP_NOWARN) :
 311                 NULL;
 312
 313         rcu_read_lock();
 314
 315         ca = t->prl_count < cmax ? t->prl_count : cmax;
 316
 317         if (!kp) {
 318                 /* We don't try hard to allocate much memory for
 319                  * non-root users.
 320                  * For root users, retry allocating enough memory for
 321                  * the answer.
 322                  */
 323                 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
 324                 if (!kp) {
 325                         ret = -ENOMEM;
 326                         goto out;
 327                 }
 328         }
 329
 330         c = 0;
 331         for_each_prl_rcu(t->prl) {
 332                 if (c >= cmax)
 333                         break;
 334                 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
 335                         continue;
 336                 kp[c].addr = prl->addr;
 337                 kp[c].flags = prl->flags;
 338                 c++;
 339                 if (kprl.addr != htonl(INADDR_ANY))
 340                         break;
 341         }
 342 out:
 343         rcu_read_unlock();
 344
 345         len = sizeof(*kp) * c;
 346         ret = 0;
 347         if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
 348                 ret = -EFAULT;
 349
 350         kfree(kp);
 351
 352         return ret;
 353 }
 354
 355 static int
 356 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
 357 {
 358         struct ip_tunnel_prl_entry *p;
 359         int err = 0;
 360
 361         if (a->addr == htonl(INADDR_ANY))
 362                 return -EINVAL;
 363
 364         ASSERT_RTNL();
 365
 366         for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
 367                 if (p->addr == a->addr) {
 368                         if (chg) {
 369                                 p->flags = a->flags;
 370                                 goto out;
 371                         }
 372                         err = -EEXIST;
 373                         goto out;
 374                 }
 375         }
 376
 377         if (chg) {
 378                 err = -ENXIO;
 379                 goto out;
 380         }
 381
 382         p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
 383         if (!p) {
 384                 err = -ENOBUFS;
 385                 goto out;
 386         }
 387
 388         p->next = t->prl;
 389         p->addr = a->addr;
 390         p->flags = a->flags;
 391         t->prl_count++;
 392         rcu_assign_pointer(t->prl, p);
 393 out:
 394         return err;
 395 }
 396
 397 static void prl_list_destroy_rcu(struct rcu_head *head)
 398 {
 399         struct ip_tunnel_prl_entry *p, *n;
 400
 401         p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
 402         do {
 403                 n = rcu_dereference_protected(p->next, 1);
 404                 kfree(p);
 405                 p = n;
 406         } while (p);
 407 }
 408
 409 static int
 410 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
 411 {
 412         struct ip_tunnel_prl_entry *x;
 413         struct ip_tunnel_prl_entry __rcu **p;
 414         int err = 0;
 415
 416         ASSERT_RTNL();
 417
 418         if (a && a->addr != htonl(INADDR_ANY)) {
 419                 for (p = &t->prl;
 420                      (x = rtnl_dereference(*p)) != NULL;
 421                      p = &x->next) {
 422                         if (x->addr == a->addr) {
 423                                 *p = x->next;
 424                                 kfree_rcu(x, rcu_head);
 425                                 t->prl_count--;
 426                                 goto out;
 427                         }
 428                 }
 429                 err = -ENXIO;
 430         } else {
 431                 x = rtnl_dereference(t->prl);
 432                 if (x) {
 433                         t->prl_count = 0;
 434                         call_rcu(&x->rcu_head, prl_list_destroy_rcu);
 435                         t->prl = NULL;
 436                 }
 437         }
 438 out:
 439         return err;
 440 }
 441
 442 static int
 443 isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
 444 {
 445         struct ip_tunnel_prl_entry *p;
 446         int ok = 1;
 447
 448         rcu_read_lock();
 449         p = __ipip6_tunnel_locate_prl(t, iph->saddr);
 450         if (p) {
 451                 if (p->flags & PRL_DEFAULT)
 452                         skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
 453                 else
 454                         skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
 455         } else {
 456                 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
 457
 458                 if (ipv6_addr_is_isatap(addr6) &&
 459                     (addr6->s6_addr32[3] == iph->saddr) &&
 460                     ipv6_chk_prefix(addr6, t->dev))
 461                         skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
 462                 else
 463                         ok = 0;
 464         }
 465         rcu_read_unlock();
 466         return ok;
 467 }
 468
 469 static void ipip6_tunnel_uninit(struct net_device *dev)
 470 {
 471         struct ip_tunnel *tunnel = netdev_priv(dev);
 472         struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
 473
 474         if (dev == sitn->fb_tunnel_dev) {
 475                 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
 476         } else {
 477                 ipip6_tunnel_unlink(sitn, tunnel);
 478                 ipip6_tunnel_del_prl(tunnel, NULL);
 479         }
 480         dst_cache_reset(&tunnel->dst_cache);
 481         dev_put(dev);
 482 }
 483
 484 static int ipip6_err(struct sk_buff *skb, u32 info)
 485 {
 486         const struct iphdr *iph = (const struct iphdr *)skb->data;
 487         const int type = icmp_hdr(skb)->type;
 488         const int code = icmp_hdr(skb)->code;
 489         unsigned int data_len = 0;
 490         struct ip_tunnel *t;
 491         int err;
 492
 493         switch (type) {
 494         default:
 495         case ICMP_PARAMETERPROB:
 496                 return 0;
 497
 498         case ICMP_DEST_UNREACH:
 499                 switch (code) {
 500                 case ICMP_SR_FAILED:
 501                         /* Impossible event. */
 502                         return 0;
 503                 default:
 504                         /* All others are translated to HOST_UNREACH.
 505                            rfc2003 contains "deep thoughts" about NET_UNREACH,
 506                            I believe they are just ether pollution. --ANK
 507                          */
 508                         break;
 509                 }
 510                 break;
 511         case ICMP_TIME_EXCEEDED:
 512                 if (code != ICMP_EXC_TTL)
 513                         return 0;
 514                 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
 515                 break;
 516         case ICMP_REDIRECT:
 517                 break;
 518         }
 519
 520         err = -ENOENT;
 521
 522         t = ipip6_tunnel_lookup(dev_net(skb->dev),
 523                                 skb->dev,
 524                                 iph->daddr,
 525                                 iph->saddr);
 526         if (!t)
 527                 goto out;
 528
 529         if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
 530                 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
 531                                  t->parms.link, 0, iph->protocol, 0);
 532                 err = 0;
 533                 goto out;
 534         }
 535         if (type == ICMP_REDIRECT) {
 536                 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0,
 537                               iph->protocol, 0);
 538                 err = 0;
 539                 goto out;
 540         }
 541
 542         err = 0;
 543         if (!ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
 544                 goto out;
 545
 546         if (t->parms.iph.daddr == 0)
 547                 goto out;
 548
 549         if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
 550                 goto out;
 551
 552         if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
 553                 t->err_count++;
 554         else
 555                 t->err_count = 1;
 556         t->err_time = jiffies;
 557 out:
 558         return err;
 559 }
 560
 561 static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
 562                                   const struct in6_addr *v6addr)
 563 {
 564         __be32 v4embed = 0;
 565         if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
 566                 return true;
 567         return false;
 568 }
 569
 570 /* Checks if an address matches an address on the tunnel interface.
 571  * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
 572  * Long story:
 573  * This function is called after we considered the packet as spoofed
 574  * in is_spoofed_6rd.
 575  * We may have a router that is doing NAT for proto 41 packets
 576  * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
 577  * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
 578  * function will return true, dropping the packet.
 579  * But, we can still check if is spoofed against the IP
 580  * addresses associated with the interface.
 581  */
 582 static bool only_dnatted(const struct ip_tunnel *tunnel,
 583         const struct in6_addr *v6dst)
 584 {
 585         int prefix_len;
 586
 587 #ifdef CONFIG_IPV6_SIT_6RD
 588         prefix_len = tunnel->ip6rd.prefixlen + 32
 589                 - tunnel->ip6rd.relay_prefixlen;
 590 #else
 591         prefix_len = 48;
 592 #endif
 593         return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
 594 }
 595
 596 /* Returns true if a packet is spoofed */
 597 static bool packet_is_spoofed(struct sk_buff *skb,
 598                               const struct iphdr *iph,
 599                               struct ip_tunnel *tunnel)
 600 {
 601         const struct ipv6hdr *ipv6h;
 602
 603         if (tunnel->dev->priv_flags & IFF_ISATAP) {
 604                 if (!isatap_chksrc(skb, iph, tunnel))
 605                         return true;
 606
 607                 return false;
 608         }
 609
 610         if (tunnel->dev->flags & IFF_POINTOPOINT)
 611                 return false;
 612
 613         ipv6h = ipv6_hdr(skb);
 614
 615         if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
 616                 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
 617                                      &iph->saddr, &ipv6h->saddr,
 618                                      &iph->daddr, &ipv6h->daddr);
 619                 return true;
 620         }
 621
 622         if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
 623                 return false;
 624
 625         if (only_dnatted(tunnel, &ipv6h->daddr))
 626                 return false;
 627
 628         net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
 629                              &iph->saddr, &ipv6h->saddr,
 630                              &iph->daddr, &ipv6h->daddr);
 631         return true;
 632 }
 633
 634 static int ipip6_rcv(struct sk_buff *skb)
 635 {
 636         const struct iphdr *iph = ip_hdr(skb);
 637         struct ip_tunnel *tunnel;
 638         int err;
 639
 640         tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 641                                      iph->saddr, iph->daddr);
 642         if (tunnel) {
 643                 struct pcpu_sw_netstats *tstats;
 644
 645                 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
 646                     tunnel->parms.iph.protocol != 0)
 647                         goto out;
 648
 649                 skb->mac_header = skb->network_header;
 650                 skb_reset_network_header(skb);
 651                 IPCB(skb)->flags = 0;
 652                 skb->dev = tunnel->dev;
 653
 654                 if (packet_is_spoofed(skb, iph, tunnel)) {
 655                         tunnel->dev->stats.rx_errors++;
 656                         goto out;
 657                 }
 658
 659                 if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
 660                     !net_eq(tunnel->net, dev_net(tunnel->dev))))
 661                         goto out;
 662
 663                 err = IP_ECN_decapsulate(iph, skb);
 664                 if (unlikely(err)) {
 665                         if (log_ecn_error)
 666                                 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
 667                                                      &iph->saddr, iph->tos);
 668                         if (err > 1) {
 669                                 ++tunnel->dev->stats.rx_frame_errors;
 670                                 ++tunnel->dev->stats.rx_errors;
 671                                 goto out;
 672                         }
 673                 }
 674
 675                 tstats = this_cpu_ptr(tunnel->dev->tstats);
 676                 u64_stats_update_begin(&tstats->syncp);
 677                 tstats->rx_packets++;
 678                 tstats->rx_bytes += skb->len;
 679                 u64_stats_update_end(&tstats->syncp);
 680
 681                 netif_rx(skb);
 682
 683                 return 0;
 684         }
 685
 686         /* no tunnel matched,  let upstream know, ipsec may handle it */
 687         return 1;
 688 out:
 689         kfree_skb(skb);
 690         return 0;
 691 }
 692
 693 static const struct tnl_ptk_info ipip_tpi = {
 694         /* no tunnel info required for ipip. */
 695         .proto = htons(ETH_P_IP),
 696 };
 697
 698 #if IS_ENABLED(CONFIG_MPLS)
 699 static const struct tnl_ptk_info mplsip_tpi = {
 700         /* no tunnel info required for mplsip. */
 701         .proto = htons(ETH_P_MPLS_UC),
 702 };
 703 #endif
 704
 705 static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
 706 {
 707         const struct iphdr *iph;
 708         struct ip_tunnel *tunnel;
 709
 710         iph = ip_hdr(skb);
 711         tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 712                                      iph->saddr, iph->daddr);
 713         if (tunnel) {
 714                 const struct tnl_ptk_info *tpi;
 715
 716                 if (tunnel->parms.iph.protocol != ipproto &&
 717                     tunnel->parms.iph.protocol != 0)
 718                         goto drop;
 719
 720                 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
 721                         goto drop;
 722 #if IS_ENABLED(CONFIG_MPLS)
 723                 if (ipproto == IPPROTO_MPLS)
 724                         tpi = &mplsip_tpi;
 725                 else
 726 #endif
 727                         tpi = &ipip_tpi;
 728                 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
 729                         goto drop;
 730                 return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
 731         }
 732
 733         return 1;
 734
 735 drop:
 736         kfree_skb(skb);
 737         return 0;
 738 }
 739
 740 static int ipip_rcv(struct sk_buff *skb)
 741 {
 742         return sit_tunnel_rcv(skb, IPPROTO_IPIP);
 743 }
 744
 745 #if IS_ENABLED(CONFIG_MPLS)
 746 static int mplsip_rcv(struct sk_buff *skb)
 747 {
 748         return sit_tunnel_rcv(skb, IPPROTO_MPLS);
 749 }
 750 #endif
 751
 752 /*
 753  * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
 754  * stores the embedded IPv4 address in v4dst and returns true.
 755  */
 756 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
 757                       __be32 *v4dst)
 758 {
 759 #ifdef CONFIG_IPV6_SIT_6RD
 760         if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
 761                               tunnel->ip6rd.prefixlen)) {
 762                 unsigned int pbw0, pbi0;
 763                 int pbi1;
 764                 u32 d;
 765
 766                 pbw0 = tunnel->ip6rd.prefixlen >> 5;
 767                 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
 768
 769                 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
 770                     tunnel->ip6rd.relay_prefixlen;
 771
 772                 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
 773                 if (pbi1 > 0)
 774                         d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
 775                              (32 - pbi1);
 776
 777                 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
 778                 return true;
 779         }
 780 #else
 781         if (v6dst->s6_addr16[0] == htons(0x2002)) {
 782                 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
 783                 memcpy(v4dst, &v6dst->s6_addr16[1], 4);
 784                 return true;
 785         }
 786 #endif
 787         return false;
 788 }
 789
 790 static inline __be32 try_6rd(struct ip_tunnel *tunnel,
 791                              const struct in6_addr *v6dst)
 792 {
 793         __be32 dst = 0;
 794         check_6rd(tunnel, v6dst, &dst);
 795         return dst;
 796 }
 797
 798 /*
 799  *      This function assumes it is being called from dev_queue_xmit()
 800  *      and that skb is filled properly by that function.
 801  */
 802
 803 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 804                                      struct net_device *dev)
 805 {
 806         struct ip_tunnel *tunnel = netdev_priv(dev);
 807         const struct iphdr  *tiph = &tunnel->parms.iph;
 808         const struct ipv6hdr *iph6 = ipv6_hdr(skb);
 809         u8     tos = tunnel->parms.iph.tos;
 810         __be16 df = tiph->frag_off;
 811         struct rtable *rt;              /* Route to the other host */
 812         struct net_device *tdev;        /* Device to other host */
 813         unsigned int max_headroom;      /* The extra header space needed */
 814         __be32 dst = tiph->daddr;
 815         struct flowi4 fl4;
 816         int    mtu;
 817         const struct in6_addr *addr6;
 818         int addr_type;
 819         u8 ttl;
 820         u8 protocol = IPPROTO_IPV6;
 821         int t_hlen = tunnel->hlen + sizeof(struct iphdr);
 822
 823         if (tos == 1)
 824                 tos = ipv6_get_dsfield(iph6);
 825
 826         /* ISATAP (RFC4214) - must come before 6to4 */
 827         if (dev->priv_flags & IFF_ISATAP) {
 828                 struct neighbour *neigh = NULL;
 829                 bool do_tx_error = false;
 830
 831                 if (skb_dst(skb))
 832                         neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 833
 834                 if (!neigh) {
 835                         net_dbg_ratelimited("nexthop == NULL\n");
 836                         goto tx_error;
 837                 }
 838
 839                 addr6 = (const struct in6_addr *)&neigh->primary_key;
 840                 addr_type = ipv6_addr_type(addr6);
 841
 842                 if ((addr_type & IPV6_ADDR_UNICAST) &&
 843                      ipv6_addr_is_isatap(addr6))
 844                         dst = addr6->s6_addr32[3];
 845                 else
 846                         do_tx_error = true;
 847
 848                 neigh_release(neigh);
 849                 if (do_tx_error)
 850                         goto tx_error;
 851         }
 852
 853         if (!dst)
 854                 dst = try_6rd(tunnel, &iph6->daddr);
 855
 856         if (!dst) {
 857                 struct neighbour *neigh = NULL;
 858                 bool do_tx_error = false;
 859
 860                 if (skb_dst(skb))
 861                         neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 862
 863                 if (!neigh) {
 864                         net_dbg_ratelimited("nexthop == NULL\n");
 865                         goto tx_error;
 866                 }
 867
 868                 addr6 = (const struct in6_addr *)&neigh->primary_key;
 869                 addr_type = ipv6_addr_type(addr6);
 870
 871                 if (addr_type == IPV6_ADDR_ANY) {
 872                         addr6 = &ipv6_hdr(skb)->daddr;
 873                         addr_type = ipv6_addr_type(addr6);
 874                 }
 875
 876                 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
 877                         dst = addr6->s6_addr32[3];
 878                 else
 879                         do_tx_error = true;
 880
 881                 neigh_release(neigh);
 882                 if (do_tx_error)
 883                         goto tx_error;
 884         }
 885
 886         flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark,
 887                            RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6,
 888                            0, dst, tiph->saddr, 0, 0,
 889                            sock_net_uid(tunnel->net, NULL));
 890         rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
 891
 892         if (IS_ERR(rt)) {
 893                 dev->stats.tx_carrier_errors++;
 894                 goto tx_error_icmp;
 895         }
 896         if (rt->rt_type != RTN_UNICAST) {
 897                 ip_rt_put(rt);
 898                 dev->stats.tx_carrier_errors++;
 899                 goto tx_error_icmp;
 900         }
 901         tdev = rt->dst.dev;
 902
 903         if (tdev == dev) {
 904                 ip_rt_put(rt);
 905                 dev->stats.collisions++;
 906                 goto tx_error;
 907         }
 908
 909         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) {
 910                 ip_rt_put(rt);
 911                 goto tx_error;
 912         }
 913
 914         if (df) {
 915                 mtu = dst_mtu(&rt->dst) - t_hlen;
 916
 917                 if (mtu < 68) {
 918                         dev->stats.collisions++;
 919                         ip_rt_put(rt);
 920                         goto tx_error;
 921                 }
 922
 923                 if (mtu < IPV6_MIN_MTU) {
 924                         mtu = IPV6_MIN_MTU;
 925                         df = 0;
 926                 }
 927
 928                 if (tunnel->parms.iph.daddr)
 929                         skb_dst_update_pmtu(skb, mtu);
 930
 931                 if (skb->len > mtu && !skb_is_gso(skb)) {
 932                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 933                         ip_rt_put(rt);
 934                         goto tx_error;
 935                 }
 936         }
 937
 938         if (tunnel->err_count > 0) {
 939                 if (time_before(jiffies,
 940                                 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
 941                         tunnel->err_count--;
 942                         dst_link_failure(skb);
 943                 } else
 944                         tunnel->err_count = 0;
 945         }
 946
 947         /*
 948          * Okay, now see if we can stuff it in the buffer as-is.
 949          */
 950         max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
 951
 952         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 953             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 954                 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
 955                 if (!new_skb) {
 956                         ip_rt_put(rt);
 957                         dev->stats.tx_dropped++;
 958                         kfree_skb(skb);
 959                         return NETDEV_TX_OK;
 960                 }
 961                 if (skb->sk)
 962                         skb_set_owner_w(new_skb, skb->sk);
 963                 dev_kfree_skb(skb);
 964                 skb = new_skb;
 965                 iph6 = ipv6_hdr(skb);
 966         }
 967         ttl = tiph->ttl;
 968         if (ttl == 0)
 969                 ttl = iph6->hop_limit;
 970         tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
 971
 972         if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) {
 973                 ip_rt_put(rt);
 974                 goto tx_error;
 975         }
 976
 977         skb_set_inner_ipproto(skb, IPPROTO_IPV6);
 978
 979         iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
 980                       df, !net_eq(tunnel->net, dev_net(dev)));
 981         return NETDEV_TX_OK;
 982
 983 tx_error_icmp:
 984         dst_link_failure(skb);
 985 tx_error:
 986         kfree_skb(skb);
 987         dev->stats.tx_errors++;
 988         return NETDEV_TX_OK;
 989 }
 990
 991 static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb,
 992                                      struct net_device *dev, u8 ipproto)
 993 {
 994         struct ip_tunnel *tunnel = netdev_priv(dev);
 995         const struct iphdr  *tiph = &tunnel->parms.iph;
 996
 997         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
 998                 goto tx_error;
 999
1000         skb_set_inner_ipproto(skb, ipproto);
1001
1002         ip_tunnel_xmit(skb, dev, tiph, ipproto);
1003         return NETDEV_TX_OK;
1004 tx_error:
1005         kfree_skb(skb);
1006         dev->stats.tx_errors++;
1007         return NETDEV_TX_OK;
1008 }
1009
1010 static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1011                                    struct net_device *dev)
1012 {
1013         switch (skb->protocol) {
1014         case htons(ETH_P_IP):
1015                 sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP);
1016                 break;
1017         case htons(ETH_P_IPV6):
1018                 ipip6_tunnel_xmit(skb, dev);
1019                 break;
1020 #if IS_ENABLED(CONFIG_MPLS)
1021         case htons(ETH_P_MPLS_UC):
1022                 sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS);
1023                 break;
1024 #endif
1025         default:
1026                 goto tx_err;
1027         }
1028
1029         return NETDEV_TX_OK;
1030
1031 tx_err:
1032         dev->stats.tx_errors++;
1033         kfree_skb(skb);
1034         return NETDEV_TX_OK;
1035
1036 }
1037
1038 static void ipip6_tunnel_bind_dev(struct net_device *dev)
1039 {
1040         struct net_device *tdev = NULL;
1041         struct ip_tunnel *tunnel;
1042         const struct iphdr *iph;
1043         struct flowi4 fl4;
1044
1045         tunnel = netdev_priv(dev);
1046         iph = &tunnel->parms.iph;
1047
1048         if (iph->daddr) {
1049                 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1050                                                           NULL,
1051                                                           iph->daddr, iph->saddr,
1052                                                           0, 0,
1053                                                           IPPROTO_IPV6,
1054                                                           RT_TOS(iph->tos),
1055                                                           tunnel->parms.link);
1056
1057                 if (!IS_ERR(rt)) {
1058                         tdev = rt->dst.dev;
1059                         ip_rt_put(rt);
1060                 }
1061                 dev->flags |= IFF_POINTOPOINT;
1062         }
1063
1064         if (!tdev && tunnel->parms.link)
1065                 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1066
1067         if (tdev) {
1068                 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1069
1070                 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
1071                 dev->mtu = tdev->mtu - t_hlen;
1072                 if (dev->mtu < IPV6_MIN_MTU)
1073                         dev->mtu = IPV6_MIN_MTU;
1074         }
1075 }
1076
1077 static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p,
1078                                 __u32 fwmark)
1079 {
1080         struct net *net = t->net;
1081         struct sit_net *sitn = net_generic(net, sit_net_id);
1082
1083         ipip6_tunnel_unlink(sitn, t);
1084         synchronize_net();
1085         t->parms.iph.saddr = p->iph.saddr;
1086         t->parms.iph.daddr = p->iph.daddr;
1087         memcpy(t->dev->dev_addr, &p->iph.saddr, 4);
1088         memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1089         ipip6_tunnel_link(sitn, t);
1090         t->parms.iph.ttl = p->iph.ttl;
1091         t->parms.iph.tos = p->iph.tos;
1092         t->parms.iph.frag_off = p->iph.frag_off;
1093         if (t->parms.link != p->link || t->fwmark != fwmark) {
1094                 t->parms.link = p->link;
1095                 t->fwmark = fwmark;
1096                 ipip6_tunnel_bind_dev(t->dev);
1097         }
1098         dst_cache_reset(&t->dst_cache);
1099         netdev_state_change(t->dev);
1100 }
1101
1102 #ifdef CONFIG_IPV6_SIT_6RD
1103 static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1104                                    struct ip_tunnel_6rd *ip6rd)
1105 {
1106         struct in6_addr prefix;
1107         __be32 relay_prefix;
1108
1109         if (ip6rd->relay_prefixlen > 32 ||
1110             ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1111                 return -EINVAL;
1112
1113         ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1114         if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1115                 return -EINVAL;
1116         if (ip6rd->relay_prefixlen)
1117                 relay_prefix = ip6rd->relay_prefix &
1118                                htonl(0xffffffffUL <<
1119                                      (32 - ip6rd->relay_prefixlen));
1120         else
1121                 relay_prefix = 0;
1122         if (relay_prefix != ip6rd->relay_prefix)
1123                 return -EINVAL;
1124
1125         t->ip6rd.prefix = prefix;
1126         t->ip6rd.relay_prefix = relay_prefix;
1127         t->ip6rd.prefixlen = ip6rd->prefixlen;
1128         t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1129         dst_cache_reset(&t->dst_cache);
1130         netdev_state_change(t->dev);
1131         return 0;
1132 }
1133 #endif
1134
1135 static bool ipip6_valid_ip_proto(u8 ipproto)
1136 {
1137         return ipproto == IPPROTO_IPV6 ||
1138                 ipproto == IPPROTO_IPIP ||
1139 #if IS_ENABLED(CONFIG_MPLS)
1140                 ipproto == IPPROTO_MPLS ||
1141 #endif
1142                 ipproto == 0;
1143 }
1144
1145 static int
1146 ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1147 {
1148         int err = 0;
1149         struct ip_tunnel_parm p;
1150         struct ip_tunnel_prl prl;
1151         struct ip_tunnel *t = netdev_priv(dev);
1152         struct net *net = t->net;
1153         struct sit_net *sitn = net_generic(net, sit_net_id);
1154 #ifdef CONFIG_IPV6_SIT_6RD
1155         struct ip_tunnel_6rd ip6rd;
1156 #endif
1157
1158         switch (cmd) {
1159         case SIOCGETTUNNEL:
1160 #ifdef CONFIG_IPV6_SIT_6RD
1161         case SIOCGET6RD:
1162 #endif
1163                 if (dev == sitn->fb_tunnel_dev) {
1164                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1165                                 err = -EFAULT;
1166                                 break;
1167                         }
1168                         t = ipip6_tunnel_locate(net, &p, 0);
1169                         if (!t)
1170                                 t = netdev_priv(dev);
1171                 }
1172
1173                 err = -EFAULT;
1174                 if (cmd == SIOCGETTUNNEL) {
1175                         memcpy(&p, &t->parms, sizeof(p));
1176                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
1177                                          sizeof(p)))
1178                                 goto done;
1179 #ifdef CONFIG_IPV6_SIT_6RD
1180                 } else {
1181                         ip6rd.prefix = t->ip6rd.prefix;
1182                         ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1183                         ip6rd.prefixlen = t->ip6rd.prefixlen;
1184                         ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1185                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
1186                                          sizeof(ip6rd)))
1187                                 goto done;
1188 #endif
1189                 }
1190                 err = 0;
1191                 break;
1192
1193         case SIOCADDTUNNEL:
1194         case SIOCCHGTUNNEL:
1195                 err = -EPERM;
1196                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1197                         goto done;
1198
1199                 err = -EFAULT;
1200                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1201                         goto done;
1202
1203                 err = -EINVAL;
1204                 if (!ipip6_valid_ip_proto(p.iph.protocol))
1205                         goto done;
1206                 if (p.iph.version != 4 ||
1207                     p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
1208                         goto done;
1209                 if (p.iph.ttl)
1210                         p.iph.frag_off |= htons(IP_DF);
1211
1212                 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1213
1214                 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1215                         if (t) {
1216                                 if (t->dev != dev) {
1217                                         err = -EEXIST;
1218                                         break;
1219                                 }
1220                         } else {
1221                                 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
1222                                     (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
1223                                         err = -EINVAL;
1224                                         break;
1225                                 }
1226                                 t = netdev_priv(dev);
1227                         }
1228
1229                         ipip6_tunnel_update(t, &p, t->fwmark);
1230                 }
1231
1232                 if (t) {
1233                         err = 0;
1234                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1235                                 err = -EFAULT;
1236                 } else
1237                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1238                 break;
1239
1240         case SIOCDELTUNNEL:
1241                 err = -EPERM;
1242                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1243                         goto done;
1244
1245                 if (dev == sitn->fb_tunnel_dev) {
1246                         err = -EFAULT;
1247                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1248                                 goto done;
1249                         err = -ENOENT;
1250                         t = ipip6_tunnel_locate(net, &p, 0);
1251                         if (!t)
1252                                 goto done;
1253                         err = -EPERM;
1254                         if (t == netdev_priv(sitn->fb_tunnel_dev))
1255                                 goto done;
1256                         dev = t->dev;
1257                 }
1258                 unregister_netdevice(dev);
1259                 err = 0;
1260                 break;
1261
1262         case SIOCGETPRL:
1263                 err = -EINVAL;
1264                 if (dev == sitn->fb_tunnel_dev)
1265                         goto done;
1266                 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1267                 break;
1268
1269         case SIOCADDPRL:
1270         case SIOCDELPRL:
1271         case SIOCCHGPRL:
1272                 err = -EPERM;
1273                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1274                         goto done;
1275                 err = -EINVAL;
1276                 if (dev == sitn->fb_tunnel_dev)
1277                         goto done;
1278                 err = -EFAULT;
1279                 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1280                         goto done;
1281
1282                 switch (cmd) {
1283                 case SIOCDELPRL:
1284                         err = ipip6_tunnel_del_prl(t, &prl);
1285                         break;
1286                 case SIOCADDPRL:
1287                 case SIOCCHGPRL:
1288                         err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1289                         break;
1290                 }
1291                 dst_cache_reset(&t->dst_cache);
1292                 netdev_state_change(dev);
1293                 break;
1294
1295 #ifdef CONFIG_IPV6_SIT_6RD
1296         case SIOCADD6RD:
1297         case SIOCCHG6RD:
1298         case SIOCDEL6RD:
1299                 err = -EPERM;
1300                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1301                         goto done;
1302
1303                 err = -EFAULT;
1304                 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1305                                    sizeof(ip6rd)))
1306                         goto done;
1307
1308                 if (cmd != SIOCDEL6RD) {
1309                         err = ipip6_tunnel_update_6rd(t, &ip6rd);
1310                         if (err < 0)
1311                                 goto done;
1312                 } else
1313                         ipip6_tunnel_clone_6rd(dev, sitn);
1314
1315                 err = 0;
1316                 break;
1317 #endif
1318
1319         default:
1320                 err = -EINVAL;
1321         }
1322
1323 done:
1324         return err;
1325 }
1326
1327 static const struct net_device_ops ipip6_netdev_ops = {
1328         .ndo_init       = ipip6_tunnel_init,
1329         .ndo_uninit     = ipip6_tunnel_uninit,
1330         .ndo_start_xmit = sit_tunnel_xmit,
1331         .ndo_do_ioctl   = ipip6_tunnel_ioctl,
1332         .ndo_get_stats64 = ip_tunnel_get_stats64,
1333         .ndo_get_iflink = ip_tunnel_get_iflink,
1334 };
1335
1336 static void ipip6_dev_free(struct net_device *dev)
1337 {
1338         struct ip_tunnel *tunnel = netdev_priv(dev);
1339
1340         dst_cache_destroy(&tunnel->dst_cache);
1341         free_percpu(dev->tstats);
1342 }
1343
1344 #define SIT_FEATURES (NETIF_F_SG           | \
1345                       NETIF_F_FRAGLIST     | \
1346                       NETIF_F_HIGHDMA      | \
1347                       NETIF_F_GSO_SOFTWARE | \
1348                       NETIF_F_HW_CSUM)
1349
1350 static void ipip6_tunnel_setup(struct net_device *dev)
1351 {
1352         struct ip_tunnel *tunnel = netdev_priv(dev);
1353         int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1354
1355         dev->netdev_ops         = &ipip6_netdev_ops;
1356         dev->needs_free_netdev  = true;
1357         dev->priv_destructor    = ipip6_dev_free;
1358
1359         dev->type               = ARPHRD_SIT;
1360         dev->hard_header_len    = LL_MAX_HEADER + t_hlen;
1361         dev->mtu                = ETH_DATA_LEN - t_hlen;
1362         dev->min_mtu            = IPV6_MIN_MTU;
1363         dev->max_mtu            = 0xFFF8 - t_hlen;
1364         dev->flags              = IFF_NOARP;
1365         netif_keep_dst(dev);
1366         dev->addr_len           = 4;
1367         dev->features           |= NETIF_F_LLTX;
1368         dev->features           |= SIT_FEATURES;
1369         dev->hw_features        |= SIT_FEATURES;
1370 }
1371
1372 static int ipip6_tunnel_init(struct net_device *dev)
1373 {
1374         struct ip_tunnel *tunnel = netdev_priv(dev);
1375         int err;
1376
1377         tunnel->dev = dev;
1378         tunnel->net = dev_net(dev);
1379         strcpy(tunnel->parms.name, dev->name);
1380
1381         ipip6_tunnel_bind_dev(dev);
1382         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1383         if (!dev->tstats)
1384                 return -ENOMEM;
1385
1386         err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1387         if (err) {
1388                 free_percpu(dev->tstats);
1389                 dev->tstats = NULL;
1390                 return err;
1391         }
1392
1393         return 0;
1394 }
1395
1396 static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1397 {
1398         struct ip_tunnel *tunnel = netdev_priv(dev);
1399         struct iphdr *iph = &tunnel->parms.iph;
1400         struct net *net = dev_net(dev);
1401         struct sit_net *sitn = net_generic(net, sit_net_id);
1402
1403         iph->version            = 4;
1404         iph->protocol           = IPPROTO_IPV6;
1405         iph->ihl                = 5;
1406         iph->ttl                = 64;
1407
1408         dev_hold(dev);
1409         rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1410 }
1411
1412 static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[],
1413                           struct netlink_ext_ack *extack)
1414 {
1415         u8 proto;
1416
1417         if (!data || !data[IFLA_IPTUN_PROTO])
1418                 return 0;
1419
1420         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1421         if (!ipip6_valid_ip_proto(proto))
1422                 return -EINVAL;
1423
1424         return 0;
1425 }
1426
1427 static void ipip6_netlink_parms(struct nlattr *data[],
1428                                 struct ip_tunnel_parm *parms,
1429                                 __u32 *fwmark)
1430 {
1431         memset(parms, 0, sizeof(*parms));
1432
1433         parms->iph.version = 4;
1434         parms->iph.protocol = IPPROTO_IPV6;
1435         parms->iph.ihl = 5;
1436         parms->iph.ttl = 64;
1437
1438         if (!data)
1439                 return;
1440
1441         if (data[IFLA_IPTUN_LINK])
1442                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1443
1444         if (data[IFLA_IPTUN_LOCAL])
1445                 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1446
1447         if (data[IFLA_IPTUN_REMOTE])
1448                 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1449
1450         if (data[IFLA_IPTUN_TTL]) {
1451                 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1452                 if (parms->iph.ttl)
1453                         parms->iph.frag_off = htons(IP_DF);
1454         }
1455
1456         if (data[IFLA_IPTUN_TOS])
1457                 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1458
1459         if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1460                 parms->iph.frag_off = htons(IP_DF);
1461
1462         if (data[IFLA_IPTUN_FLAGS])
1463                 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1464
1465         if (data[IFLA_IPTUN_PROTO])
1466                 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1467
1468         if (data[IFLA_IPTUN_FWMARK])
1469                 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1470 }
1471
1472 /* This function returns true when ENCAP attributes are present in the nl msg */
1473 static bool ipip6_netlink_encap_parms(struct nlattr *data[],
1474                                       struct ip_tunnel_encap *ipencap)
1475 {
1476         bool ret = false;
1477
1478         memset(ipencap, 0, sizeof(*ipencap));
1479
1480         if (!data)
1481                 return ret;
1482
1483         if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1484                 ret = true;
1485                 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1486         }
1487
1488         if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1489                 ret = true;
1490                 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1491         }
1492
1493         if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1494                 ret = true;
1495                 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1496         }
1497
1498         if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1499                 ret = true;
1500                 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1501         }
1502
1503         return ret;
1504 }
1505
1506 #ifdef CONFIG_IPV6_SIT_6RD
1507 /* This function returns true when 6RD attributes are present in the nl msg */
1508 static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1509                                     struct ip_tunnel_6rd *ip6rd)
1510 {
1511         bool ret = false;
1512         memset(ip6rd, 0, sizeof(*ip6rd));
1513
1514         if (!data)
1515                 return ret;
1516
1517         if (data[IFLA_IPTUN_6RD_PREFIX]) {
1518                 ret = true;
1519                 ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]);
1520         }
1521
1522         if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1523                 ret = true;
1524                 ip6rd->relay_prefix =
1525                         nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1526         }
1527
1528         if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1529                 ret = true;
1530                 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1531         }
1532
1533         if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1534                 ret = true;
1535                 ip6rd->relay_prefixlen =
1536                         nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1537         }
1538
1539         return ret;
1540 }
1541 #endif
1542
1543 static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1544                          struct nlattr *tb[], struct nlattr *data[],
1545                          struct netlink_ext_ack *extack)
1546 {
1547         struct net *net = dev_net(dev);
1548         struct ip_tunnel *nt;
1549         struct ip_tunnel_encap ipencap;
1550 #ifdef CONFIG_IPV6_SIT_6RD
1551         struct ip_tunnel_6rd ip6rd;
1552 #endif
1553         int err;
1554
1555         nt = netdev_priv(dev);
1556
1557         if (ipip6_netlink_encap_parms(data, &ipencap)) {
1558                 err = ip_tunnel_encap_setup(nt, &ipencap);
1559                 if (err < 0)
1560                         return err;
1561         }
1562
1563         ipip6_netlink_parms(data, &nt->parms, &nt->fwmark);
1564
1565         if (ipip6_tunnel_locate(net, &nt->parms, 0))
1566                 return -EEXIST;
1567
1568         err = ipip6_tunnel_create(dev);
1569         if (err < 0)
1570                 return err;
1571
1572 #ifdef CONFIG_IPV6_SIT_6RD
1573         if (ipip6_netlink_6rd_parms(data, &ip6rd))
1574                 err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1575 #endif
1576
1577         return err;
1578 }
1579
1580 static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1581                             struct nlattr *data[],
1582                             struct netlink_ext_ack *extack)
1583 {
1584         struct ip_tunnel *t = netdev_priv(dev);
1585         struct ip_tunnel_parm p;
1586         struct ip_tunnel_encap ipencap;
1587         struct net *net = t->net;
1588         struct sit_net *sitn = net_generic(net, sit_net_id);
1589 #ifdef CONFIG_IPV6_SIT_6RD
1590         struct ip_tunnel_6rd ip6rd;
1591 #endif
1592         __u32 fwmark = t->fwmark;
1593         int err;
1594
1595         if (dev == sitn->fb_tunnel_dev)
1596                 return -EINVAL;
1597
1598         if (ipip6_netlink_encap_parms(data, &ipencap)) {
1599                 err = ip_tunnel_encap_setup(t, &ipencap);
1600                 if (err < 0)
1601                         return err;
1602         }
1603
1604         ipip6_netlink_parms(data, &p, &fwmark);
1605
1606         if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1607             (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1608                 return -EINVAL;
1609
1610         t = ipip6_tunnel_locate(net, &p, 0);
1611
1612         if (t) {
1613                 if (t->dev != dev)
1614                         return -EEXIST;
1615         } else
1616                 t = netdev_priv(dev);
1617
1618         ipip6_tunnel_update(t, &p, fwmark);
1619
1620 #ifdef CONFIG_IPV6_SIT_6RD
1621         if (ipip6_netlink_6rd_parms(data, &ip6rd))
1622                 return ipip6_tunnel_update_6rd(t, &ip6rd);
1623 #endif
1624
1625         return 0;
1626 }
1627
1628 static size_t ipip6_get_size(const struct net_device *dev)
1629 {
1630         return
1631                 /* IFLA_IPTUN_LINK */
1632                 nla_total_size(4) +
1633                 /* IFLA_IPTUN_LOCAL */
1634                 nla_total_size(4) +
1635                 /* IFLA_IPTUN_REMOTE */
1636                 nla_total_size(4) +
1637                 /* IFLA_IPTUN_TTL */
1638                 nla_total_size(1) +
1639                 /* IFLA_IPTUN_TOS */
1640                 nla_total_size(1) +
1641                 /* IFLA_IPTUN_PMTUDISC */
1642                 nla_total_size(1) +
1643                 /* IFLA_IPTUN_FLAGS */
1644                 nla_total_size(2) +
1645                 /* IFLA_IPTUN_PROTO */
1646                 nla_total_size(1) +
1647 #ifdef CONFIG_IPV6_SIT_6RD
1648                 /* IFLA_IPTUN_6RD_PREFIX */
1649                 nla_total_size(sizeof(struct in6_addr)) +
1650                 /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1651                 nla_total_size(4) +
1652                 /* IFLA_IPTUN_6RD_PREFIXLEN */
1653                 nla_total_size(2) +
1654                 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1655                 nla_total_size(2) +
1656 #endif
1657                 /* IFLA_IPTUN_ENCAP_TYPE */
1658                 nla_total_size(2) +
1659                 /* IFLA_IPTUN_ENCAP_FLAGS */
1660                 nla_total_size(2) +
1661                 /* IFLA_IPTUN_ENCAP_SPORT */
1662                 nla_total_size(2) +
1663                 /* IFLA_IPTUN_ENCAP_DPORT */
1664                 nla_total_size(2) +
1665                 /* IFLA_IPTUN_FWMARK */
1666                 nla_total_size(4) +
1667                 0;
1668 }
1669
1670 static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1671 {
1672         struct ip_tunnel *tunnel = netdev_priv(dev);
1673         struct ip_tunnel_parm *parm = &tunnel->parms;
1674
1675         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1676             nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1677             nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1678             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1679             nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1680             nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1681                        !!(parm->iph.frag_off & htons(IP_DF))) ||
1682             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1683             nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags) ||
1684             nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
1685                 goto nla_put_failure;
1686
1687 #ifdef CONFIG_IPV6_SIT_6RD
1688         if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX,
1689                              &tunnel->ip6rd.prefix) ||
1690             nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1691                             tunnel->ip6rd.relay_prefix) ||
1692             nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1693                         tunnel->ip6rd.prefixlen) ||
1694             nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1695                         tunnel->ip6rd.relay_prefixlen))
1696                 goto nla_put_failure;
1697 #endif
1698
1699         if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
1700                         tunnel->encap.type) ||
1701             nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
1702                         tunnel->encap.sport) ||
1703             nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
1704                         tunnel->encap.dport) ||
1705             nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
1706                         tunnel->encap.flags))
1707                 goto nla_put_failure;
1708
1709         return 0;
1710
1711 nla_put_failure:
1712         return -EMSGSIZE;
1713 }
1714
1715 static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1716         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
1717         [IFLA_IPTUN_LOCAL]              = { .type = NLA_U32 },
1718         [IFLA_IPTUN_REMOTE]             = { .type = NLA_U32 },
1719         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
1720         [IFLA_IPTUN_TOS]                = { .type = NLA_U8 },
1721         [IFLA_IPTUN_PMTUDISC]           = { .type = NLA_U8 },
1722         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U16 },
1723         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
1724 #ifdef CONFIG_IPV6_SIT_6RD
1725         [IFLA_IPTUN_6RD_PREFIX]         = { .len = sizeof(struct in6_addr) },
1726         [IFLA_IPTUN_6RD_RELAY_PREFIX]   = { .type = NLA_U32 },
1727         [IFLA_IPTUN_6RD_PREFIXLEN]      = { .type = NLA_U16 },
1728         [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1729 #endif
1730         [IFLA_IPTUN_ENCAP_TYPE]         = { .type = NLA_U16 },
1731         [IFLA_IPTUN_ENCAP_FLAGS]        = { .type = NLA_U16 },
1732         [IFLA_IPTUN_ENCAP_SPORT]        = { .type = NLA_U16 },
1733         [IFLA_IPTUN_ENCAP_DPORT]        = { .type = NLA_U16 },
1734         [IFLA_IPTUN_FWMARK]             = { .type = NLA_U32 },
1735 };
1736
1737 static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1738 {
1739         struct net *net = dev_net(dev);
1740         struct sit_net *sitn = net_generic(net, sit_net_id);
1741
1742         if (dev != sitn->fb_tunnel_dev)
1743                 unregister_netdevice_queue(dev, head);
1744 }
1745
1746 static struct rtnl_link_ops sit_link_ops __read_mostly = {
1747         .kind           = "sit",
1748         .maxtype        = IFLA_IPTUN_MAX,
1749         .policy         = ipip6_policy,
1750         .priv_size      = sizeof(struct ip_tunnel),
1751         .setup          = ipip6_tunnel_setup,
1752         .validate       = ipip6_validate,
1753         .newlink        = ipip6_newlink,
1754         .changelink     = ipip6_changelink,
1755         .get_size       = ipip6_get_size,
1756         .fill_info      = ipip6_fill_info,
1757         .dellink        = ipip6_dellink,
1758         .get_link_net   = ip_tunnel_get_link_net,
1759 };
1760
1761 static struct xfrm_tunnel sit_handler __read_mostly = {
1762         .handler        =       ipip6_rcv,
1763         .err_handler    =       ipip6_err,
1764         .priority       =       1,
1765 };
1766
1767 static struct xfrm_tunnel ipip_handler __read_mostly = {
1768         .handler        =       ipip_rcv,
1769         .err_handler    =       ipip6_err,
1770         .priority       =       2,
1771 };
1772
1773 #if IS_ENABLED(CONFIG_MPLS)
1774 static struct xfrm_tunnel mplsip_handler __read_mostly = {
1775         .handler        =       mplsip_rcv,
1776         .err_handler    =       ipip6_err,
1777         .priority       =       2,
1778 };
1779 #endif
1780
1781 static void __net_exit sit_destroy_tunnels(struct net *net,
1782                                            struct list_head *head)
1783 {
1784         struct sit_net *sitn = net_generic(net, sit_net_id);
1785         struct net_device *dev, *aux;
1786         int prio;
1787
1788         for_each_netdev_safe(net, dev, aux)
1789                 if (dev->rtnl_link_ops == &sit_link_ops)
1790                         unregister_netdevice_queue(dev, head);
1791
1792         for (prio = 1; prio < 4; prio++) {
1793                 int h;
1794                 for (h = 0; h < IP6_SIT_HASH_SIZE; h++) {
1795                         struct ip_tunnel *t;
1796
1797                         t = rtnl_dereference(sitn->tunnels[prio][h]);
1798                         while (t) {
1799                                 /* If dev is in the same netns, it has already
1800                                  * been added to the list by the previous loop.
1801                                  */
1802                                 if (!net_eq(dev_net(t->dev), net))
1803                                         unregister_netdevice_queue(t->dev,
1804                                                                    head);
1805                                 t = rtnl_dereference(t->next);
1806                         }
1807                 }
1808         }
1809 }
1810
1811 static int __net_init sit_init_net(struct net *net)
1812 {
1813         struct sit_net *sitn = net_generic(net, sit_net_id);
1814         struct ip_tunnel *t;
1815         int err;
1816
1817         sitn->tunnels[0] = sitn->tunnels_wc;
1818         sitn->tunnels[1] = sitn->tunnels_l;
1819         sitn->tunnels[2] = sitn->tunnels_r;
1820         sitn->tunnels[3] = sitn->tunnels_r_l;
1821
1822         sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1823                                            NET_NAME_UNKNOWN,
1824                                            ipip6_tunnel_setup);
1825         if (!sitn->fb_tunnel_dev) {
1826                 err = -ENOMEM;
1827                 goto err_alloc_dev;
1828         }
1829         dev_net_set(sitn->fb_tunnel_dev, net);
1830         sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1831         /* FB netdevice is special: we have one, and only one per netns.
1832          * Allowing to move it to another netns is clearly unsafe.
1833          */
1834         sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1835
1836         err = register_netdev(sitn->fb_tunnel_dev);
1837         if (err)
1838                 goto err_reg_dev;
1839
1840         ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1841         ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1842
1843         t = netdev_priv(sitn->fb_tunnel_dev);
1844
1845         strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1846         return 0;
1847
1848 err_reg_dev:
1849         ipip6_dev_free(sitn->fb_tunnel_dev);
1850 err_alloc_dev:
1851         return err;
1852 }
1853
1854 static void __net_exit sit_exit_net(struct net *net)
1855 {
1856         LIST_HEAD(list);
1857
1858         rtnl_lock();
1859         sit_destroy_tunnels(net, &list);
1860         unregister_netdevice_many(&list);
1861         rtnl_unlock();
1862 }
1863
1864 static struct pernet_operations sit_net_ops = {
1865         .init = sit_init_net,
1866         .exit = sit_exit_net,
1867         .id   = &sit_net_id,
1868         .size = sizeof(struct sit_net),
1869 };
1870
1871 static void __exit sit_cleanup(void)
1872 {
1873         rtnl_link_unregister(&sit_link_ops);
1874         xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1875         xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1876 #if IS_ENABLED(CONFIG_MPLS)
1877         xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1878 #endif
1879
1880         unregister_pernet_device(&sit_net_ops);
1881         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1882 }
1883
1884 static int __init sit_init(void)
1885 {
1886         int err;
1887
1888         pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n");
1889
1890         err = register_pernet_device(&sit_net_ops);
1891         if (err < 0)
1892                 return err;
1893         err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1894         if (err < 0) {
1895                 pr_info("%s: can't register ip6ip4\n", __func__);
1896                 goto xfrm_tunnel_failed;
1897         }
1898         err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1899         if (err < 0) {
1900                 pr_info("%s: can't register ip4ip4\n", __func__);
1901                 goto xfrm_tunnel4_failed;
1902         }
1903 #if IS_ENABLED(CONFIG_MPLS)
1904         err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
1905         if (err < 0) {
1906                 pr_info("%s: can't register mplsip\n", __func__);
1907                 goto xfrm_tunnel_mpls_failed;
1908         }
1909 #endif
1910         err = rtnl_link_register(&sit_link_ops);
1911         if (err < 0)
1912                 goto rtnl_link_failed;
1913
1914 out:
1915         return err;
1916
1917 rtnl_link_failed:
1918 #if IS_ENABLED(CONFIG_MPLS)
1919         xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1920 xfrm_tunnel_mpls_failed:
1921 #endif
1922         xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1923 xfrm_tunnel4_failed:
1924         xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1925 xfrm_tunnel_failed:
1926         unregister_pernet_device(&sit_net_ops);
1927         goto out;
1928 }
1929
1930 module_init(sit_init);
1931 module_exit(sit_cleanup);
1932 MODULE_LICENSE("GPL");
1933 MODULE_ALIAS_RTNL_LINK("sit");
1934 MODULE_ALIAS_NETDEV("sit0");