net/ipv6/sit.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
   4  *      Linux INET6 implementation
   5  *
   6  *      Authors:
   7  *      Pedro Roque             <roque@di.fc.ul.pt>
   8  *      Alexey Kuznetsov        <kuznet@ms2.inr.ac.ru>
   9  *
  10  *      Changes:
  11  * Roger Venning <r.venning@telstra.com>:       6to4 support
  12  * Nate Thompson <nate@thebog.net>:             6to4 support
  13  * Fred Templin <fred.l.templin@boeing.com>:    isatap support
  14  */
  15
  16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  17
  18 #include <linux/module.h>
  19 #include <linux/capability.h>
  20 #include <linux/errno.h>
  21 #include <linux/types.h>
  22 #include <linux/socket.h>
  23 #include <linux/sockios.h>
  24 #include <linux/net.h>
  25 #include <linux/in6.h>
  26 #include <linux/netdevice.h>
  27 #include <linux/if_arp.h>
  28 #include <linux/icmp.h>
  29 #include <linux/slab.h>
  30 #include <linux/uaccess.h>
  31 #include <linux/init.h>
  32 #include <linux/netfilter_ipv4.h>
  33 #include <linux/if_ether.h>
  34
  35 #include <net/sock.h>
  36 #include <net/snmp.h>
  37
  38 #include <net/ipv6.h>
  39 #include <net/protocol.h>
  40 #include <net/transp_v6.h>
  41 #include <net/ip6_fib.h>
  42 #include <net/ip6_route.h>
  43 #include <net/ndisc.h>
  44 #include <net/addrconf.h>
  45 #include <net/ip.h>
  46 #include <net/udp.h>
  47 #include <net/icmp.h>
  48 #include <net/ip_tunnels.h>
  49 #include <net/inet_ecn.h>
  50 #include <net/xfrm.h>
  51 #include <net/dsfield.h>
  52 #include <net/net_namespace.h>
  53 #include <net/netns/generic.h>
  54
  55 /*
  56    This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
  57
  58    For comments look at net/ipv4/ip_gre.c --ANK
  59  */
  60
  61 #define IP6_SIT_HASH_SIZE  16
  62 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
  63
  64 static bool log_ecn_error = true;
  65 module_param(log_ecn_error, bool, 0644);
  66 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  67
  68 static int ipip6_tunnel_init(struct net_device *dev);
  69 static void ipip6_tunnel_setup(struct net_device *dev);
  70 static void ipip6_dev_free(struct net_device *dev);
  71 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
  72                       __be32 *v4dst);
  73 static struct rtnl_link_ops sit_link_ops __read_mostly;
  74
  75 static unsigned int sit_net_id __read_mostly;
  76 struct sit_net {
  77         struct ip_tunnel __rcu *tunnels_r_l[IP6_SIT_HASH_SIZE];
  78         struct ip_tunnel __rcu *tunnels_r[IP6_SIT_HASH_SIZE];
  79         struct ip_tunnel __rcu *tunnels_l[IP6_SIT_HASH_SIZE];
  80         struct ip_tunnel __rcu *tunnels_wc[1];
  81         struct ip_tunnel __rcu **tunnels[4];
  82
  83         struct net_device *fb_tunnel_dev;
  84 };
  85
  86 /*
  87  * Must be invoked with rcu_read_lock
  88  */
  89 static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
  90                                              struct net_device *dev,
  91                                              __be32 remote, __be32 local,
  92                                              int sifindex)
  93 {
  94         unsigned int h0 = HASH(remote);
  95         unsigned int h1 = HASH(local);
  96         struct ip_tunnel *t;
  97         struct sit_net *sitn = net_generic(net, sit_net_id);
  98         int ifindex = dev ? dev->ifindex : 0;
  99
 100         for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
 101                 if (local == t->parms.iph.saddr &&
 102                     remote == t->parms.iph.daddr &&
 103                     (!dev || !t->parms.link || ifindex == t->parms.link ||
 104                      sifindex == 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 || ifindex == t->parms.link ||
 111                      sifindex == t->parms.link) &&
 112                     (t->dev->flags & IFF_UP))
 113                         return t;
 114         }
 115         for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
 116                 if (local == t->parms.iph.saddr &&
 117                     (!dev || !t->parms.link || ifindex == t->parms.link ||
 118                      sifindex == t->parms.link) &&
 119                     (t->dev->flags & IFF_UP))
 120                         return t;
 121         }
 122         t = rcu_dereference(sitn->tunnels_wc[0]);
 123         if (t && (t->dev->flags & IFF_UP))
 124                 return t;
 125         return NULL;
 126 }
 127
 128 static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
 129                 struct ip_tunnel_parm *parms)
 130 {
 131         __be32 remote = parms->iph.daddr;
 132         __be32 local = parms->iph.saddr;
 133         unsigned int h = 0;
 134         int prio = 0;
 135
 136         if (remote) {
 137                 prio |= 2;
 138                 h ^= HASH(remote);
 139         }
 140         if (local) {
 141                 prio |= 1;
 142                 h ^= HASH(local);
 143         }
 144         return &sitn->tunnels[prio][h];
 145 }
 146
 147 static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
 148                 struct ip_tunnel *t)
 149 {
 150         return __ipip6_bucket(sitn, &t->parms);
 151 }
 152
 153 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
 154 {
 155         struct ip_tunnel __rcu **tp;
 156         struct ip_tunnel *iter;
 157
 158         for (tp = ipip6_bucket(sitn, t);
 159              (iter = rtnl_dereference(*tp)) != NULL;
 160              tp = &iter->next) {
 161                 if (t == iter) {
 162                         rcu_assign_pointer(*tp, t->next);
 163                         break;
 164                 }
 165         }
 166 }
 167
 168 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
 169 {
 170         struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
 171
 172         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 173         rcu_assign_pointer(*tp, t);
 174 }
 175
 176 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
 177 {
 178 #ifdef CONFIG_IPV6_SIT_6RD
 179         struct ip_tunnel *t = netdev_priv(dev);
 180
 181         if (dev == sitn->fb_tunnel_dev || !sitn->fb_tunnel_dev) {
 182                 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
 183                 t->ip6rd.relay_prefix = 0;
 184                 t->ip6rd.prefixlen = 16;
 185                 t->ip6rd.relay_prefixlen = 0;
 186         } else {
 187                 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
 188                 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
 189         }
 190 #endif
 191 }
 192
 193 static int ipip6_tunnel_create(struct net_device *dev)
 194 {
 195         struct ip_tunnel *t = netdev_priv(dev);
 196         struct net *net = dev_net(dev);
 197         struct sit_net *sitn = net_generic(net, sit_net_id);
 198         int err;
 199
 200         memcpy(dev->dev_addr, &t->parms.iph.saddr, 4);
 201         memcpy(dev->broadcast, &t->parms.iph.daddr, 4);
 202
 203         if ((__force u16)t->parms.i_flags & SIT_ISATAP)
 204                 dev->priv_flags |= IFF_ISATAP;
 205
 206         dev->rtnl_link_ops = &sit_link_ops;
 207
 208         err = register_netdevice(dev);
 209         if (err < 0)
 210                 goto out;
 211
 212         ipip6_tunnel_clone_6rd(dev, sitn);
 213
 214         dev_hold(dev);
 215
 216         ipip6_tunnel_link(sitn, t);
 217         return 0;
 218
 219 out:
 220         return err;
 221 }
 222
 223 static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
 224                 struct ip_tunnel_parm *parms, int create)
 225 {
 226         __be32 remote = parms->iph.daddr;
 227         __be32 local = parms->iph.saddr;
 228         struct ip_tunnel *t, *nt;
 229         struct ip_tunnel __rcu **tp;
 230         struct net_device *dev;
 231         char name[IFNAMSIZ];
 232         struct sit_net *sitn = net_generic(net, sit_net_id);
 233
 234         for (tp = __ipip6_bucket(sitn, parms);
 235             (t = rtnl_dereference(*tp)) != NULL;
 236              tp = &t->next) {
 237                 if (local == t->parms.iph.saddr &&
 238                     remote == t->parms.iph.daddr &&
 239                     parms->link == t->parms.link) {
 240                         if (create)
 241                                 return NULL;
 242                         else
 243                                 return t;
 244                 }
 245         }
 246         if (!create)
 247                 goto failed;
 248
 249         if (parms->name[0]) {
 250                 if (!dev_valid_name(parms->name))
 251                         goto failed;
 252                 strlcpy(name, parms->name, IFNAMSIZ);
 253         } else {
 254                 strcpy(name, "sit%d");
 255         }
 256         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 257                            ipip6_tunnel_setup);
 258         if (!dev)
 259                 return NULL;
 260
 261         dev_net_set(dev, net);
 262
 263         nt = netdev_priv(dev);
 264
 265         nt->parms = *parms;
 266         if (ipip6_tunnel_create(dev) < 0)
 267                 goto failed_free;
 268
 269         return nt;
 270
 271 failed_free:
 272         free_netdev(dev);
 273 failed:
 274         return NULL;
 275 }
 276
 277 #define for_each_prl_rcu(start)                 \
 278         for (prl = rcu_dereference(start);      \
 279              prl;                               \
 280              prl = rcu_dereference(prl->next))
 281
 282 static struct ip_tunnel_prl_entry *
 283 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
 284 {
 285         struct ip_tunnel_prl_entry *prl;
 286
 287         for_each_prl_rcu(t->prl)
 288                 if (prl->addr == addr)
 289                         break;
 290         return prl;
 291
 292 }
 293
 294 static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
 295                                 struct ip_tunnel_prl __user *a)
 296 {
 297         struct ip_tunnel_prl kprl, *kp;
 298         struct ip_tunnel_prl_entry *prl;
 299         unsigned int cmax, c = 0, ca, len;
 300         int ret = 0;
 301
 302         if (copy_from_user(&kprl, a, sizeof(kprl)))
 303                 return -EFAULT;
 304         cmax = kprl.datalen / sizeof(kprl);
 305         if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
 306                 cmax = 1;
 307
 308         /* For simple GET or for root users,
 309          * we try harder to allocate.
 310          */
 311         kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
 312                 kcalloc(cmax, sizeof(*kp), GFP_KERNEL | __GFP_NOWARN) :
 313                 NULL;
 314
 315         rcu_read_lock();
 316
 317         ca = t->prl_count < cmax ? t->prl_count : cmax;
 318
 319         if (!kp) {
 320                 /* We don't try hard to allocate much memory for
 321                  * non-root users.
 322                  * For root users, retry allocating enough memory for
 323                  * the answer.
 324                  */
 325                 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
 326                 if (!kp) {
 327                         ret = -ENOMEM;
 328                         goto out;
 329                 }
 330         }
 331
 332         c = 0;
 333         for_each_prl_rcu(t->prl) {
 334                 if (c >= cmax)
 335                         break;
 336                 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
 337                         continue;
 338                 kp[c].addr = prl->addr;
 339                 kp[c].flags = prl->flags;
 340                 c++;
 341                 if (kprl.addr != htonl(INADDR_ANY))
 342                         break;
 343         }
 344 out:
 345         rcu_read_unlock();
 346
 347         len = sizeof(*kp) * c;
 348         ret = 0;
 349         if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
 350                 ret = -EFAULT;
 351
 352         kfree(kp);
 353
 354         return ret;
 355 }
 356
 357 static int
 358 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
 359 {
 360         struct ip_tunnel_prl_entry *p;
 361         int err = 0;
 362
 363         if (a->addr == htonl(INADDR_ANY))
 364                 return -EINVAL;
 365
 366         ASSERT_RTNL();
 367
 368         for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
 369                 if (p->addr == a->addr) {
 370                         if (chg) {
 371                                 p->flags = a->flags;
 372                                 goto out;
 373                         }
 374                         err = -EEXIST;
 375                         goto out;
 376                 }
 377         }
 378
 379         if (chg) {
 380                 err = -ENXIO;
 381                 goto out;
 382         }
 383
 384         p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
 385         if (!p) {
 386                 err = -ENOBUFS;
 387                 goto out;
 388         }
 389
 390         p->next = t->prl;
 391         p->addr = a->addr;
 392         p->flags = a->flags;
 393         t->prl_count++;
 394         rcu_assign_pointer(t->prl, p);
 395 out:
 396         return err;
 397 }
 398
 399 static void prl_list_destroy_rcu(struct rcu_head *head)
 400 {
 401         struct ip_tunnel_prl_entry *p, *n;
 402
 403         p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
 404         do {
 405                 n = rcu_dereference_protected(p->next, 1);
 406                 kfree(p);
 407                 p = n;
 408         } while (p);
 409 }
 410
 411 static int
 412 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
 413 {
 414         struct ip_tunnel_prl_entry *x;
 415         struct ip_tunnel_prl_entry __rcu **p;
 416         int err = 0;
 417
 418         ASSERT_RTNL();
 419
 420         if (a && a->addr != htonl(INADDR_ANY)) {
 421                 for (p = &t->prl;
 422                      (x = rtnl_dereference(*p)) != NULL;
 423                      p = &x->next) {
 424                         if (x->addr == a->addr) {
 425                                 *p = x->next;
 426                                 kfree_rcu(x, rcu_head);
 427                                 t->prl_count--;
 428                                 goto out;
 429                         }
 430                 }
 431                 err = -ENXIO;
 432         } else {
 433                 x = rtnl_dereference(t->prl);
 434                 if (x) {
 435                         t->prl_count = 0;
 436                         call_rcu(&x->rcu_head, prl_list_destroy_rcu);
 437                         t->prl = NULL;
 438                 }
 439         }
 440 out:
 441         return err;
 442 }
 443
 444 static int
 445 isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
 446 {
 447         struct ip_tunnel_prl_entry *p;
 448         int ok = 1;
 449
 450         rcu_read_lock();
 451         p = __ipip6_tunnel_locate_prl(t, iph->saddr);
 452         if (p) {
 453                 if (p->flags & PRL_DEFAULT)
 454                         skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
 455                 else
 456                         skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
 457         } else {
 458                 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
 459
 460                 if (ipv6_addr_is_isatap(addr6) &&
 461                     (addr6->s6_addr32[3] == iph->saddr) &&
 462                     ipv6_chk_prefix(addr6, t->dev))
 463                         skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
 464                 else
 465                         ok = 0;
 466         }
 467         rcu_read_unlock();
 468         return ok;
 469 }
 470
 471 static void ipip6_tunnel_uninit(struct net_device *dev)
 472 {
 473         struct ip_tunnel *tunnel = netdev_priv(dev);
 474         struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
 475
 476         if (dev == sitn->fb_tunnel_dev) {
 477                 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
 478         } else {
 479                 ipip6_tunnel_unlink(sitn, tunnel);
 480                 ipip6_tunnel_del_prl(tunnel, NULL);
 481         }
 482         dst_cache_reset(&tunnel->dst_cache);
 483         dev_put(dev);
 484 }
 485
 486 static int ipip6_err(struct sk_buff *skb, u32 info)
 487 {
 488         const struct iphdr *iph = (const struct iphdr *)skb->data;
 489         const int type = icmp_hdr(skb)->type;
 490         const int code = icmp_hdr(skb)->code;
 491         unsigned int data_len = 0;
 492         struct ip_tunnel *t;
 493         int sifindex;
 494         int err;
 495
 496         switch (type) {
 497         default:
 498         case ICMP_PARAMETERPROB:
 499                 return 0;
 500
 501         case ICMP_DEST_UNREACH:
 502                 switch (code) {
 503                 case ICMP_SR_FAILED:
 504                         /* Impossible event. */
 505                         return 0;
 506                 default:
 507                         /* All others are translated to HOST_UNREACH.
 508                            rfc2003 contains "deep thoughts" about NET_UNREACH,
 509                            I believe they are just ether pollution. --ANK
 510                          */
 511                         break;
 512                 }
 513                 break;
 514         case ICMP_TIME_EXCEEDED:
 515                 if (code != ICMP_EXC_TTL)
 516                         return 0;
 517                 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
 518                 break;
 519         case ICMP_REDIRECT:
 520                 break;
 521         }
 522
 523         err = -ENOENT;
 524
 525         sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
 526         t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 527                                 iph->daddr, iph->saddr, sifindex);
 528         if (!t)
 529                 goto out;
 530
 531         if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
 532                 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
 533                                  t->parms.link, iph->protocol);
 534                 err = 0;
 535                 goto out;
 536         }
 537         if (type == ICMP_REDIRECT) {
 538                 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link,
 539                               iph->protocol);
 540                 err = 0;
 541                 goto out;
 542         }
 543
 544         err = 0;
 545         if (__in6_dev_get(skb->dev) &&
 546             !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
 547                 goto out;
 548
 549         if (t->parms.iph.daddr == 0)
 550                 goto out;
 551
 552         if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
 553                 goto out;
 554
 555         if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
 556                 t->err_count++;
 557         else
 558                 t->err_count = 1;
 559         t->err_time = jiffies;
 560 out:
 561         return err;
 562 }
 563
 564 static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
 565                                   const struct in6_addr *v6addr)
 566 {
 567         __be32 v4embed = 0;
 568         if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
 569                 return true;
 570         return false;
 571 }
 572
 573 /* Checks if an address matches an address on the tunnel interface.
 574  * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
 575  * Long story:
 576  * This function is called after we considered the packet as spoofed
 577  * in is_spoofed_6rd.
 578  * We may have a router that is doing NAT for proto 41 packets
 579  * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
 580  * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
 581  * function will return true, dropping the packet.
 582  * But, we can still check if is spoofed against the IP
 583  * addresses associated with the interface.
 584  */
 585 static bool only_dnatted(const struct ip_tunnel *tunnel,
 586         const struct in6_addr *v6dst)
 587 {
 588         int prefix_len;
 589
 590 #ifdef CONFIG_IPV6_SIT_6RD
 591         prefix_len = tunnel->ip6rd.prefixlen + 32
 592                 - tunnel->ip6rd.relay_prefixlen;
 593 #else
 594         prefix_len = 48;
 595 #endif
 596         return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
 597 }
 598
 599 /* Returns true if a packet is spoofed */
 600 static bool packet_is_spoofed(struct sk_buff *skb,
 601                               const struct iphdr *iph,
 602                               struct ip_tunnel *tunnel)
 603 {
 604         const struct ipv6hdr *ipv6h;
 605
 606         if (tunnel->dev->priv_flags & IFF_ISATAP) {
 607                 if (!isatap_chksrc(skb, iph, tunnel))
 608                         return true;
 609
 610                 return false;
 611         }
 612
 613         if (tunnel->dev->flags & IFF_POINTOPOINT)
 614                 return false;
 615
 616         ipv6h = ipv6_hdr(skb);
 617
 618         if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
 619                 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
 620                                      &iph->saddr, &ipv6h->saddr,
 621                                      &iph->daddr, &ipv6h->daddr);
 622                 return true;
 623         }
 624
 625         if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
 626                 return false;
 627
 628         if (only_dnatted(tunnel, &ipv6h->daddr))
 629                 return false;
 630
 631         net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
 632                              &iph->saddr, &ipv6h->saddr,
 633                              &iph->daddr, &ipv6h->daddr);
 634         return true;
 635 }
 636
 637 static int ipip6_rcv(struct sk_buff *skb)
 638 {
 639         const struct iphdr *iph = ip_hdr(skb);
 640         struct ip_tunnel *tunnel;
 641         int sifindex;
 642         int err;
 643
 644         sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
 645         tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 646                                      iph->saddr, iph->daddr, sifindex);
 647         if (tunnel) {
 648                 struct pcpu_sw_netstats *tstats;
 649
 650                 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
 651                     tunnel->parms.iph.protocol != 0)
 652                         goto out;
 653
 654                 skb->mac_header = skb->network_header;
 655                 skb_reset_network_header(skb);
 656                 IPCB(skb)->flags = 0;
 657                 skb->dev = tunnel->dev;
 658
 659                 if (packet_is_spoofed(skb, iph, tunnel)) {
 660                         tunnel->dev->stats.rx_errors++;
 661                         goto out;
 662                 }
 663
 664                 if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
 665                     !net_eq(tunnel->net, dev_net(tunnel->dev))))
 666                         goto out;
 667
 668                 /* skb can be uncloned in iptunnel_pull_header, so
 669                  * old iph is no longer valid
 670                  */
 671                 iph = (const struct iphdr *)skb_mac_header(skb);
 672                 err = IP_ECN_decapsulate(iph, skb);
 673                 if (unlikely(err)) {
 674                         if (log_ecn_error)
 675                                 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
 676                                                      &iph->saddr, iph->tos);
 677                         if (err > 1) {
 678                                 ++tunnel->dev->stats.rx_frame_errors;
 679                                 ++tunnel->dev->stats.rx_errors;
 680                                 goto out;
 681                         }
 682                 }
 683
 684                 tstats = this_cpu_ptr(tunnel->dev->tstats);
 685                 u64_stats_update_begin(&tstats->syncp);
 686                 tstats->rx_packets++;
 687                 tstats->rx_bytes += skb->len;
 688                 u64_stats_update_end(&tstats->syncp);
 689
 690                 netif_rx(skb);
 691
 692                 return 0;
 693         }
 694
 695         /* no tunnel matched,  let upstream know, ipsec may handle it */
 696         return 1;
 697 out:
 698         kfree_skb(skb);
 699         return 0;
 700 }
 701
 702 static const struct tnl_ptk_info ipip_tpi = {
 703         /* no tunnel info required for ipip. */
 704         .proto = htons(ETH_P_IP),
 705 };
 706
 707 #if IS_ENABLED(CONFIG_MPLS)
 708 static const struct tnl_ptk_info mplsip_tpi = {
 709         /* no tunnel info required for mplsip. */
 710         .proto = htons(ETH_P_MPLS_UC),
 711 };
 712 #endif
 713
 714 static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
 715 {
 716         const struct iphdr *iph;
 717         struct ip_tunnel *tunnel;
 718         int sifindex;
 719
 720         sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
 721
 722         iph = ip_hdr(skb);
 723         tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 724                                      iph->saddr, iph->daddr, sifindex);
 725         if (tunnel) {
 726                 const struct tnl_ptk_info *tpi;
 727
 728                 if (tunnel->parms.iph.protocol != ipproto &&
 729                     tunnel->parms.iph.protocol != 0)
 730                         goto drop;
 731
 732                 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
 733                         goto drop;
 734 #if IS_ENABLED(CONFIG_MPLS)
 735                 if (ipproto == IPPROTO_MPLS)
 736                         tpi = &mplsip_tpi;
 737                 else
 738 #endif
 739                         tpi = &ipip_tpi;
 740                 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
 741                         goto drop;
 742                 return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
 743         }
 744
 745         return 1;
 746
 747 drop:
 748         kfree_skb(skb);
 749         return 0;
 750 }
 751
 752 static int ipip_rcv(struct sk_buff *skb)
 753 {
 754         return sit_tunnel_rcv(skb, IPPROTO_IPIP);
 755 }
 756
 757 #if IS_ENABLED(CONFIG_MPLS)
 758 static int mplsip_rcv(struct sk_buff *skb)
 759 {
 760         return sit_tunnel_rcv(skb, IPPROTO_MPLS);
 761 }
 762 #endif
 763
 764 /*
 765  * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
 766  * stores the embedded IPv4 address in v4dst and returns true.
 767  */
 768 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
 769                       __be32 *v4dst)
 770 {
 771 #ifdef CONFIG_IPV6_SIT_6RD
 772         if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
 773                               tunnel->ip6rd.prefixlen)) {
 774                 unsigned int pbw0, pbi0;
 775                 int pbi1;
 776                 u32 d;
 777
 778                 pbw0 = tunnel->ip6rd.prefixlen >> 5;
 779                 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
 780
 781                 d = tunnel->ip6rd.relay_prefixlen < 32 ?
 782                         (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
 783                     tunnel->ip6rd.relay_prefixlen : 0;
 784
 785                 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
 786                 if (pbi1 > 0)
 787                         d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
 788                              (32 - pbi1);
 789
 790                 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
 791                 return true;
 792         }
 793 #else
 794         if (v6dst->s6_addr16[0] == htons(0x2002)) {
 795                 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
 796                 memcpy(v4dst, &v6dst->s6_addr16[1], 4);
 797                 return true;
 798         }
 799 #endif
 800         return false;
 801 }
 802
 803 static inline __be32 try_6rd(struct ip_tunnel *tunnel,
 804                              const struct in6_addr *v6dst)
 805 {
 806         __be32 dst = 0;
 807         check_6rd(tunnel, v6dst, &dst);
 808         return dst;
 809 }
 810
 811 /*
 812  *      This function assumes it is being called from dev_queue_xmit()
 813  *      and that skb is filled properly by that function.
 814  */
 815
 816 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 817                                      struct net_device *dev)
 818 {
 819         struct ip_tunnel *tunnel = netdev_priv(dev);
 820         const struct iphdr  *tiph = &tunnel->parms.iph;
 821         const struct ipv6hdr *iph6 = ipv6_hdr(skb);
 822         u8     tos = tunnel->parms.iph.tos;
 823         __be16 df = tiph->frag_off;
 824         struct rtable *rt;              /* Route to the other host */
 825         struct net_device *tdev;        /* Device to other host */
 826         unsigned int max_headroom;      /* The extra header space needed */
 827         __be32 dst = tiph->daddr;
 828         struct flowi4 fl4;
 829         int    mtu;
 830         const struct in6_addr *addr6;
 831         int addr_type;
 832         u8 ttl;
 833         u8 protocol = IPPROTO_IPV6;
 834         int t_hlen = tunnel->hlen + sizeof(struct iphdr);
 835
 836         if (tos == 1)
 837                 tos = ipv6_get_dsfield(iph6);
 838
 839         /* ISATAP (RFC4214) - must come before 6to4 */
 840         if (dev->priv_flags & IFF_ISATAP) {
 841                 struct neighbour *neigh = NULL;
 842                 bool do_tx_error = false;
 843
 844                 if (skb_dst(skb))
 845                         neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 846
 847                 if (!neigh) {
 848                         net_dbg_ratelimited("nexthop == NULL\n");
 849                         goto tx_error;
 850                 }
 851
 852                 addr6 = (const struct in6_addr *)&neigh->primary_key;
 853                 addr_type = ipv6_addr_type(addr6);
 854
 855                 if ((addr_type & IPV6_ADDR_UNICAST) &&
 856                      ipv6_addr_is_isatap(addr6))
 857                         dst = addr6->s6_addr32[3];
 858                 else
 859                         do_tx_error = true;
 860
 861                 neigh_release(neigh);
 862                 if (do_tx_error)
 863                         goto tx_error;
 864         }
 865
 866         if (!dst)
 867                 dst = try_6rd(tunnel, &iph6->daddr);
 868
 869         if (!dst) {
 870                 struct neighbour *neigh = NULL;
 871                 bool do_tx_error = false;
 872
 873                 if (skb_dst(skb))
 874                         neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 875
 876                 if (!neigh) {
 877                         net_dbg_ratelimited("nexthop == NULL\n");
 878                         goto tx_error;
 879                 }
 880
 881                 addr6 = (const struct in6_addr *)&neigh->primary_key;
 882                 addr_type = ipv6_addr_type(addr6);
 883
 884                 if (addr_type == IPV6_ADDR_ANY) {
 885                         addr6 = &ipv6_hdr(skb)->daddr;
 886                         addr_type = ipv6_addr_type(addr6);
 887                 }
 888
 889                 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
 890                         dst = addr6->s6_addr32[3];
 891                 else
 892                         do_tx_error = true;
 893
 894                 neigh_release(neigh);
 895                 if (do_tx_error)
 896                         goto tx_error;
 897         }
 898
 899         flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark,
 900                            RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6,
 901                            0, dst, tiph->saddr, 0, 0,
 902                            sock_net_uid(tunnel->net, NULL));
 903
 904         rt = dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr);
 905         if (!rt) {
 906                 rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
 907                 if (IS_ERR(rt)) {
 908                         dev->stats.tx_carrier_errors++;
 909                         goto tx_error_icmp;
 910                 }
 911                 dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, fl4.saddr);
 912         }
 913
 914         if (rt->rt_type != RTN_UNICAST) {
 915                 ip_rt_put(rt);
 916                 dev->stats.tx_carrier_errors++;
 917                 goto tx_error_icmp;
 918         }
 919         tdev = rt->dst.dev;
 920
 921         if (tdev == dev) {
 922                 ip_rt_put(rt);
 923                 dev->stats.collisions++;
 924                 goto tx_error;
 925         }
 926
 927         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) {
 928                 ip_rt_put(rt);
 929                 goto tx_error;
 930         }
 931
 932         if (df) {
 933                 mtu = dst_mtu(&rt->dst) - t_hlen;
 934
 935                 if (mtu < 68) {
 936                         dev->stats.collisions++;
 937                         ip_rt_put(rt);
 938                         goto tx_error;
 939                 }
 940
 941                 if (mtu < IPV6_MIN_MTU) {
 942                         mtu = IPV6_MIN_MTU;
 943                         df = 0;
 944                 }
 945
 946                 if (tunnel->parms.iph.daddr)
 947                         skb_dst_update_pmtu(skb, mtu);
 948
 949                 if (skb->len > mtu && !skb_is_gso(skb)) {
 950                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 951                         ip_rt_put(rt);
 952                         goto tx_error;
 953                 }
 954         }
 955
 956         if (tunnel->err_count > 0) {
 957                 if (time_before(jiffies,
 958                                 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
 959                         tunnel->err_count--;
 960                         dst_link_failure(skb);
 961                 } else
 962                         tunnel->err_count = 0;
 963         }
 964
 965         /*
 966          * Okay, now see if we can stuff it in the buffer as-is.
 967          */
 968         max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
 969
 970         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 971             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 972                 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
 973                 if (!new_skb) {
 974                         ip_rt_put(rt);
 975                         dev->stats.tx_dropped++;
 976                         kfree_skb(skb);
 977                         return NETDEV_TX_OK;
 978                 }
 979                 if (skb->sk)
 980                         skb_set_owner_w(new_skb, skb->sk);
 981                 dev_kfree_skb(skb);
 982                 skb = new_skb;
 983                 iph6 = ipv6_hdr(skb);
 984         }
 985         ttl = tiph->ttl;
 986         if (ttl == 0)
 987                 ttl = iph6->hop_limit;
 988         tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
 989
 990         if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) {
 991                 ip_rt_put(rt);
 992                 goto tx_error;
 993         }
 994
 995         skb_set_inner_ipproto(skb, IPPROTO_IPV6);
 996
 997         iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
 998                       df, !net_eq(tunnel->net, dev_net(dev)));
 999         return NETDEV_TX_OK;
1000
1001 tx_error_icmp:
1002         dst_link_failure(skb);
1003 tx_error:
1004         kfree_skb(skb);
1005         dev->stats.tx_errors++;
1006         return NETDEV_TX_OK;
1007 }
1008
1009 static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb,
1010                                      struct net_device *dev, u8 ipproto)
1011 {
1012         struct ip_tunnel *tunnel = netdev_priv(dev);
1013         const struct iphdr  *tiph = &tunnel->parms.iph;
1014
1015         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
1016                 goto tx_error;
1017
1018         skb_set_inner_ipproto(skb, ipproto);
1019
1020         ip_tunnel_xmit(skb, dev, tiph, ipproto);
1021         return NETDEV_TX_OK;
1022 tx_error:
1023         kfree_skb(skb);
1024         dev->stats.tx_errors++;
1025         return NETDEV_TX_OK;
1026 }
1027
1028 static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1029                                    struct net_device *dev)
1030 {
1031         if (!pskb_inet_may_pull(skb))
1032                 goto tx_err;
1033
1034         switch (skb->protocol) {
1035         case htons(ETH_P_IP):
1036                 sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP);
1037                 break;
1038         case htons(ETH_P_IPV6):
1039                 ipip6_tunnel_xmit(skb, dev);
1040                 break;
1041 #if IS_ENABLED(CONFIG_MPLS)
1042         case htons(ETH_P_MPLS_UC):
1043                 sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS);
1044                 break;
1045 #endif
1046         default:
1047                 goto tx_err;
1048         }
1049
1050         return NETDEV_TX_OK;
1051
1052 tx_err:
1053         dev->stats.tx_errors++;
1054         kfree_skb(skb);
1055         return NETDEV_TX_OK;
1056
1057 }
1058
1059 static void ipip6_tunnel_bind_dev(struct net_device *dev)
1060 {
1061         struct net_device *tdev = NULL;
1062         struct ip_tunnel *tunnel;
1063         const struct iphdr *iph;
1064         struct flowi4 fl4;
1065
1066         tunnel = netdev_priv(dev);
1067         iph = &tunnel->parms.iph;
1068
1069         if (iph->daddr) {
1070                 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1071                                                           NULL,
1072                                                           iph->daddr, iph->saddr,
1073                                                           0, 0,
1074                                                           IPPROTO_IPV6,
1075                                                           RT_TOS(iph->tos),
1076                                                           tunnel->parms.link);
1077
1078                 if (!IS_ERR(rt)) {
1079                         tdev = rt->dst.dev;
1080                         ip_rt_put(rt);
1081                 }
1082                 dev->flags |= IFF_POINTOPOINT;
1083         }
1084
1085         if (!tdev && tunnel->parms.link)
1086                 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1087
1088         if (tdev && !netif_is_l3_master(tdev)) {
1089                 int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1090
1091                 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
1092                 dev->mtu = tdev->mtu - t_hlen;
1093                 if (dev->mtu < IPV6_MIN_MTU)
1094                         dev->mtu = IPV6_MIN_MTU;
1095         }
1096 }
1097
1098 static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p,
1099                                 __u32 fwmark)
1100 {
1101         struct net *net = t->net;
1102         struct sit_net *sitn = net_generic(net, sit_net_id);
1103
1104         ipip6_tunnel_unlink(sitn, t);
1105         synchronize_net();
1106         t->parms.iph.saddr = p->iph.saddr;
1107         t->parms.iph.daddr = p->iph.daddr;
1108         memcpy(t->dev->dev_addr, &p->iph.saddr, 4);
1109         memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1110         ipip6_tunnel_link(sitn, t);
1111         t->parms.iph.ttl = p->iph.ttl;
1112         t->parms.iph.tos = p->iph.tos;
1113         t->parms.iph.frag_off = p->iph.frag_off;
1114         if (t->parms.link != p->link || t->fwmark != fwmark) {
1115                 t->parms.link = p->link;
1116                 t->fwmark = fwmark;
1117                 ipip6_tunnel_bind_dev(t->dev);
1118         }
1119         dst_cache_reset(&t->dst_cache);
1120         netdev_state_change(t->dev);
1121 }
1122
1123 #ifdef CONFIG_IPV6_SIT_6RD
1124 static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1125                                    struct ip_tunnel_6rd *ip6rd)
1126 {
1127         struct in6_addr prefix;
1128         __be32 relay_prefix;
1129
1130         if (ip6rd->relay_prefixlen > 32 ||
1131             ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1132                 return -EINVAL;
1133
1134         ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1135         if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1136                 return -EINVAL;
1137         if (ip6rd->relay_prefixlen)
1138                 relay_prefix = ip6rd->relay_prefix &
1139                                htonl(0xffffffffUL <<
1140                                      (32 - ip6rd->relay_prefixlen));
1141         else
1142                 relay_prefix = 0;
1143         if (relay_prefix != ip6rd->relay_prefix)
1144                 return -EINVAL;
1145
1146         t->ip6rd.prefix = prefix;
1147         t->ip6rd.relay_prefix = relay_prefix;
1148         t->ip6rd.prefixlen = ip6rd->prefixlen;
1149         t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1150         dst_cache_reset(&t->dst_cache);
1151         netdev_state_change(t->dev);
1152         return 0;
1153 }
1154 #endif
1155
1156 static bool ipip6_valid_ip_proto(u8 ipproto)
1157 {
1158         return ipproto == IPPROTO_IPV6 ||
1159                 ipproto == IPPROTO_IPIP ||
1160 #if IS_ENABLED(CONFIG_MPLS)
1161                 ipproto == IPPROTO_MPLS ||
1162 #endif
1163                 ipproto == 0;
1164 }
1165
1166 static int
1167 ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1168 {
1169         int err = 0;
1170         struct ip_tunnel_parm p;
1171         struct ip_tunnel_prl prl;
1172         struct ip_tunnel *t = netdev_priv(dev);
1173         struct net *net = t->net;
1174         struct sit_net *sitn = net_generic(net, sit_net_id);
1175 #ifdef CONFIG_IPV6_SIT_6RD
1176         struct ip_tunnel_6rd ip6rd;
1177 #endif
1178
1179         switch (cmd) {
1180         case SIOCGETTUNNEL:
1181 #ifdef CONFIG_IPV6_SIT_6RD
1182         case SIOCGET6RD:
1183 #endif
1184                 if (dev == sitn->fb_tunnel_dev) {
1185                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1186                                 err = -EFAULT;
1187                                 break;
1188                         }
1189                         t = ipip6_tunnel_locate(net, &p, 0);
1190                         if (!t)
1191                                 t = netdev_priv(dev);
1192                 }
1193
1194                 err = -EFAULT;
1195                 if (cmd == SIOCGETTUNNEL) {
1196                         memcpy(&p, &t->parms, sizeof(p));
1197                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
1198                                          sizeof(p)))
1199                                 goto done;
1200 #ifdef CONFIG_IPV6_SIT_6RD
1201                 } else {
1202                         ip6rd.prefix = t->ip6rd.prefix;
1203                         ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1204                         ip6rd.prefixlen = t->ip6rd.prefixlen;
1205                         ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1206                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
1207                                          sizeof(ip6rd)))
1208                                 goto done;
1209 #endif
1210                 }
1211                 err = 0;
1212                 break;
1213
1214         case SIOCADDTUNNEL:
1215         case SIOCCHGTUNNEL:
1216                 err = -EPERM;
1217                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1218                         goto done;
1219
1220                 err = -EFAULT;
1221                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1222                         goto done;
1223
1224                 err = -EINVAL;
1225                 if (!ipip6_valid_ip_proto(p.iph.protocol))
1226                         goto done;
1227                 if (p.iph.version != 4 ||
1228                     p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
1229                         goto done;
1230                 if (p.iph.ttl)
1231                         p.iph.frag_off |= htons(IP_DF);
1232
1233                 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1234
1235                 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1236                         if (t) {
1237                                 if (t->dev != dev) {
1238                                         err = -EEXIST;
1239                                         break;
1240                                 }
1241                         } else {
1242                                 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
1243                                     (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
1244                                         err = -EINVAL;
1245                                         break;
1246                                 }
1247                                 t = netdev_priv(dev);
1248                         }
1249
1250                         ipip6_tunnel_update(t, &p, t->fwmark);
1251                 }
1252
1253                 if (t) {
1254                         err = 0;
1255                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1256                                 err = -EFAULT;
1257                 } else
1258                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1259                 break;
1260
1261         case SIOCDELTUNNEL:
1262                 err = -EPERM;
1263                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1264                         goto done;
1265
1266                 if (dev == sitn->fb_tunnel_dev) {
1267                         err = -EFAULT;
1268                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1269                                 goto done;
1270                         err = -ENOENT;
1271                         t = ipip6_tunnel_locate(net, &p, 0);
1272                         if (!t)
1273                                 goto done;
1274                         err = -EPERM;
1275                         if (t == netdev_priv(sitn->fb_tunnel_dev))
1276                                 goto done;
1277                         dev = t->dev;
1278                 }
1279                 unregister_netdevice(dev);
1280                 err = 0;
1281                 break;
1282
1283         case SIOCGETPRL:
1284                 err = -EINVAL;
1285                 if (dev == sitn->fb_tunnel_dev)
1286                         goto done;
1287                 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1288                 break;
1289
1290         case SIOCADDPRL:
1291         case SIOCDELPRL:
1292         case SIOCCHGPRL:
1293                 err = -EPERM;
1294                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1295                         goto done;
1296                 err = -EINVAL;
1297                 if (dev == sitn->fb_tunnel_dev)
1298                         goto done;
1299                 err = -EFAULT;
1300                 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1301                         goto done;
1302
1303                 switch (cmd) {
1304                 case SIOCDELPRL:
1305                         err = ipip6_tunnel_del_prl(t, &prl);
1306                         break;
1307                 case SIOCADDPRL:
1308                 case SIOCCHGPRL:
1309                         err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1310                         break;
1311                 }
1312                 dst_cache_reset(&t->dst_cache);
1313                 netdev_state_change(dev);
1314                 break;
1315
1316 #ifdef CONFIG_IPV6_SIT_6RD
1317         case SIOCADD6RD:
1318         case SIOCCHG6RD:
1319         case SIOCDEL6RD:
1320                 err = -EPERM;
1321                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1322                         goto done;
1323
1324                 err = -EFAULT;
1325                 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1326                                    sizeof(ip6rd)))
1327                         goto done;
1328
1329                 if (cmd != SIOCDEL6RD) {
1330                         err = ipip6_tunnel_update_6rd(t, &ip6rd);
1331                         if (err < 0)
1332                                 goto done;
1333                 } else
1334                         ipip6_tunnel_clone_6rd(dev, sitn);
1335
1336                 err = 0;
1337                 break;
1338 #endif
1339
1340         default:
1341                 err = -EINVAL;
1342         }
1343
1344 done:
1345         return err;
1346 }
1347
1348 static const struct net_device_ops ipip6_netdev_ops = {
1349         .ndo_init       = ipip6_tunnel_init,
1350         .ndo_uninit     = ipip6_tunnel_uninit,
1351         .ndo_start_xmit = sit_tunnel_xmit,
1352         .ndo_do_ioctl   = ipip6_tunnel_ioctl,
1353         .ndo_get_stats64 = ip_tunnel_get_stats64,
1354         .ndo_get_iflink = ip_tunnel_get_iflink,
1355 };
1356
1357 static void ipip6_dev_free(struct net_device *dev)
1358 {
1359         struct ip_tunnel *tunnel = netdev_priv(dev);
1360
1361         dst_cache_destroy(&tunnel->dst_cache);
1362         free_percpu(dev->tstats);
1363 }
1364
1365 #define SIT_FEATURES (NETIF_F_SG           | \
1366                       NETIF_F_FRAGLIST     | \
1367                       NETIF_F_HIGHDMA      | \
1368                       NETIF_F_GSO_SOFTWARE | \
1369                       NETIF_F_HW_CSUM)
1370
1371 static void ipip6_tunnel_setup(struct net_device *dev)
1372 {
1373         struct ip_tunnel *tunnel = netdev_priv(dev);
1374         int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1375
1376         dev->netdev_ops         = &ipip6_netdev_ops;
1377         dev->needs_free_netdev  = true;
1378         dev->priv_destructor    = ipip6_dev_free;
1379
1380         dev->type               = ARPHRD_SIT;
1381         dev->hard_header_len    = LL_MAX_HEADER + t_hlen;
1382         dev->mtu                = ETH_DATA_LEN - t_hlen;
1383         dev->min_mtu            = IPV6_MIN_MTU;
1384         dev->max_mtu            = IP6_MAX_MTU - t_hlen;
1385         dev->flags              = IFF_NOARP;
1386         netif_keep_dst(dev);
1387         dev->addr_len           = 4;
1388         dev->features           |= NETIF_F_LLTX;
1389         dev->features           |= SIT_FEATURES;
1390         dev->hw_features        |= SIT_FEATURES;
1391 }
1392
1393 static int ipip6_tunnel_init(struct net_device *dev)
1394 {
1395         struct ip_tunnel *tunnel = netdev_priv(dev);
1396         int err;
1397
1398         tunnel->dev = dev;
1399         tunnel->net = dev_net(dev);
1400         strcpy(tunnel->parms.name, dev->name);
1401
1402         ipip6_tunnel_bind_dev(dev);
1403         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1404         if (!dev->tstats)
1405                 return -ENOMEM;
1406
1407         err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1408         if (err) {
1409                 free_percpu(dev->tstats);
1410                 dev->tstats = NULL;
1411                 return err;
1412         }
1413
1414         return 0;
1415 }
1416
1417 static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1418 {
1419         struct ip_tunnel *tunnel = netdev_priv(dev);
1420         struct iphdr *iph = &tunnel->parms.iph;
1421         struct net *net = dev_net(dev);
1422         struct sit_net *sitn = net_generic(net, sit_net_id);
1423
1424         iph->version            = 4;
1425         iph->protocol           = IPPROTO_IPV6;
1426         iph->ihl                = 5;
1427         iph->ttl                = 64;
1428
1429         dev_hold(dev);
1430         rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1431 }
1432
1433 static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[],
1434                           struct netlink_ext_ack *extack)
1435 {
1436         u8 proto;
1437
1438         if (!data || !data[IFLA_IPTUN_PROTO])
1439                 return 0;
1440
1441         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1442         if (!ipip6_valid_ip_proto(proto))
1443                 return -EINVAL;
1444
1445         return 0;
1446 }
1447
1448 static void ipip6_netlink_parms(struct nlattr *data[],
1449                                 struct ip_tunnel_parm *parms,
1450                                 __u32 *fwmark)
1451 {
1452         memset(parms, 0, sizeof(*parms));
1453
1454         parms->iph.version = 4;
1455         parms->iph.protocol = IPPROTO_IPV6;
1456         parms->iph.ihl = 5;
1457         parms->iph.ttl = 64;
1458
1459         if (!data)
1460                 return;
1461
1462         if (data[IFLA_IPTUN_LINK])
1463                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1464
1465         if (data[IFLA_IPTUN_LOCAL])
1466                 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1467
1468         if (data[IFLA_IPTUN_REMOTE])
1469                 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1470
1471         if (data[IFLA_IPTUN_TTL]) {
1472                 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1473                 if (parms->iph.ttl)
1474                         parms->iph.frag_off = htons(IP_DF);
1475         }
1476
1477         if (data[IFLA_IPTUN_TOS])
1478                 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1479
1480         if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1481                 parms->iph.frag_off = htons(IP_DF);
1482
1483         if (data[IFLA_IPTUN_FLAGS])
1484                 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1485
1486         if (data[IFLA_IPTUN_PROTO])
1487                 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1488
1489         if (data[IFLA_IPTUN_FWMARK])
1490                 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1491 }
1492
1493 /* This function returns true when ENCAP attributes are present in the nl msg */
1494 static bool ipip6_netlink_encap_parms(struct nlattr *data[],
1495                                       struct ip_tunnel_encap *ipencap)
1496 {
1497         bool ret = false;
1498
1499         memset(ipencap, 0, sizeof(*ipencap));
1500
1501         if (!data)
1502                 return ret;
1503
1504         if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1505                 ret = true;
1506                 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1507         }
1508
1509         if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1510                 ret = true;
1511                 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1512         }
1513
1514         if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1515                 ret = true;
1516                 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1517         }
1518
1519         if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1520                 ret = true;
1521                 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1522         }
1523
1524         return ret;
1525 }
1526
1527 #ifdef CONFIG_IPV6_SIT_6RD
1528 /* This function returns true when 6RD attributes are present in the nl msg */
1529 static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1530                                     struct ip_tunnel_6rd *ip6rd)
1531 {
1532         bool ret = false;
1533         memset(ip6rd, 0, sizeof(*ip6rd));
1534
1535         if (!data)
1536                 return ret;
1537
1538         if (data[IFLA_IPTUN_6RD_PREFIX]) {
1539                 ret = true;
1540                 ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]);
1541         }
1542
1543         if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1544                 ret = true;
1545                 ip6rd->relay_prefix =
1546                         nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1547         }
1548
1549         if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1550                 ret = true;
1551                 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1552         }
1553
1554         if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1555                 ret = true;
1556                 ip6rd->relay_prefixlen =
1557                         nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1558         }
1559
1560         return ret;
1561 }
1562 #endif
1563
1564 static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1565                          struct nlattr *tb[], struct nlattr *data[],
1566                          struct netlink_ext_ack *extack)
1567 {
1568         struct net *net = dev_net(dev);
1569         struct ip_tunnel *nt;
1570         struct ip_tunnel_encap ipencap;
1571 #ifdef CONFIG_IPV6_SIT_6RD
1572         struct ip_tunnel_6rd ip6rd;
1573 #endif
1574         int err;
1575
1576         nt = netdev_priv(dev);
1577
1578         if (ipip6_netlink_encap_parms(data, &ipencap)) {
1579                 err = ip_tunnel_encap_setup(nt, &ipencap);
1580                 if (err < 0)
1581                         return err;
1582         }
1583
1584         ipip6_netlink_parms(data, &nt->parms, &nt->fwmark);
1585
1586         if (ipip6_tunnel_locate(net, &nt->parms, 0))
1587                 return -EEXIST;
1588
1589         err = ipip6_tunnel_create(dev);
1590         if (err < 0)
1591                 return err;
1592
1593         if (tb[IFLA_MTU]) {
1594                 u32 mtu = nla_get_u32(tb[IFLA_MTU]);
1595
1596                 if (mtu >= IPV6_MIN_MTU &&
1597                     mtu <= IP6_MAX_MTU - dev->hard_header_len)
1598                         dev->mtu = mtu;
1599         }
1600
1601 #ifdef CONFIG_IPV6_SIT_6RD
1602         if (ipip6_netlink_6rd_parms(data, &ip6rd))
1603                 err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1604 #endif
1605
1606         return err;
1607 }
1608
1609 static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1610                             struct nlattr *data[],
1611                             struct netlink_ext_ack *extack)
1612 {
1613         struct ip_tunnel *t = netdev_priv(dev);
1614         struct ip_tunnel_parm p;
1615         struct ip_tunnel_encap ipencap;
1616         struct net *net = t->net;
1617         struct sit_net *sitn = net_generic(net, sit_net_id);
1618 #ifdef CONFIG_IPV6_SIT_6RD
1619         struct ip_tunnel_6rd ip6rd;
1620 #endif
1621         __u32 fwmark = t->fwmark;
1622         int err;
1623
1624         if (dev == sitn->fb_tunnel_dev)
1625                 return -EINVAL;
1626
1627         if (ipip6_netlink_encap_parms(data, &ipencap)) {
1628                 err = ip_tunnel_encap_setup(t, &ipencap);
1629                 if (err < 0)
1630                         return err;
1631         }
1632
1633         ipip6_netlink_parms(data, &p, &fwmark);
1634
1635         if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1636             (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1637                 return -EINVAL;
1638
1639         t = ipip6_tunnel_locate(net, &p, 0);
1640
1641         if (t) {
1642                 if (t->dev != dev)
1643                         return -EEXIST;
1644         } else
1645                 t = netdev_priv(dev);
1646
1647         ipip6_tunnel_update(t, &p, fwmark);
1648
1649 #ifdef CONFIG_IPV6_SIT_6RD
1650         if (ipip6_netlink_6rd_parms(data, &ip6rd))
1651                 return ipip6_tunnel_update_6rd(t, &ip6rd);
1652 #endif
1653
1654         return 0;
1655 }
1656
1657 static size_t ipip6_get_size(const struct net_device *dev)
1658 {
1659         return
1660                 /* IFLA_IPTUN_LINK */
1661                 nla_total_size(4) +
1662                 /* IFLA_IPTUN_LOCAL */
1663                 nla_total_size(4) +
1664                 /* IFLA_IPTUN_REMOTE */
1665                 nla_total_size(4) +
1666                 /* IFLA_IPTUN_TTL */
1667                 nla_total_size(1) +
1668                 /* IFLA_IPTUN_TOS */
1669                 nla_total_size(1) +
1670                 /* IFLA_IPTUN_PMTUDISC */
1671                 nla_total_size(1) +
1672                 /* IFLA_IPTUN_FLAGS */
1673                 nla_total_size(2) +
1674                 /* IFLA_IPTUN_PROTO */
1675                 nla_total_size(1) +
1676 #ifdef CONFIG_IPV6_SIT_6RD
1677                 /* IFLA_IPTUN_6RD_PREFIX */
1678                 nla_total_size(sizeof(struct in6_addr)) +
1679                 /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1680                 nla_total_size(4) +
1681                 /* IFLA_IPTUN_6RD_PREFIXLEN */
1682                 nla_total_size(2) +
1683                 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1684                 nla_total_size(2) +
1685 #endif
1686                 /* IFLA_IPTUN_ENCAP_TYPE */
1687                 nla_total_size(2) +
1688                 /* IFLA_IPTUN_ENCAP_FLAGS */
1689                 nla_total_size(2) +
1690                 /* IFLA_IPTUN_ENCAP_SPORT */
1691                 nla_total_size(2) +
1692                 /* IFLA_IPTUN_ENCAP_DPORT */
1693                 nla_total_size(2) +
1694                 /* IFLA_IPTUN_FWMARK */
1695                 nla_total_size(4) +
1696                 0;
1697 }
1698
1699 static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1700 {
1701         struct ip_tunnel *tunnel = netdev_priv(dev);
1702         struct ip_tunnel_parm *parm = &tunnel->parms;
1703
1704         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1705             nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1706             nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1707             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1708             nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1709             nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1710                        !!(parm->iph.frag_off & htons(IP_DF))) ||
1711             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1712             nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags) ||
1713             nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
1714                 goto nla_put_failure;
1715
1716 #ifdef CONFIG_IPV6_SIT_6RD
1717         if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX,
1718                              &tunnel->ip6rd.prefix) ||
1719             nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1720                             tunnel->ip6rd.relay_prefix) ||
1721             nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1722                         tunnel->ip6rd.prefixlen) ||
1723             nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1724                         tunnel->ip6rd.relay_prefixlen))
1725                 goto nla_put_failure;
1726 #endif
1727
1728         if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
1729                         tunnel->encap.type) ||
1730             nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
1731                         tunnel->encap.sport) ||
1732             nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
1733                         tunnel->encap.dport) ||
1734             nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
1735                         tunnel->encap.flags))
1736                 goto nla_put_failure;
1737
1738         return 0;
1739
1740 nla_put_failure:
1741         return -EMSGSIZE;
1742 }
1743
1744 static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1745         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
1746         [IFLA_IPTUN_LOCAL]              = { .type = NLA_U32 },
1747         [IFLA_IPTUN_REMOTE]             = { .type = NLA_U32 },
1748         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
1749         [IFLA_IPTUN_TOS]                = { .type = NLA_U8 },
1750         [IFLA_IPTUN_PMTUDISC]           = { .type = NLA_U8 },
1751         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U16 },
1752         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
1753 #ifdef CONFIG_IPV6_SIT_6RD
1754         [IFLA_IPTUN_6RD_PREFIX]         = { .len = sizeof(struct in6_addr) },
1755         [IFLA_IPTUN_6RD_RELAY_PREFIX]   = { .type = NLA_U32 },
1756         [IFLA_IPTUN_6RD_PREFIXLEN]      = { .type = NLA_U16 },
1757         [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1758 #endif
1759         [IFLA_IPTUN_ENCAP_TYPE]         = { .type = NLA_U16 },
1760         [IFLA_IPTUN_ENCAP_FLAGS]        = { .type = NLA_U16 },
1761         [IFLA_IPTUN_ENCAP_SPORT]        = { .type = NLA_U16 },
1762         [IFLA_IPTUN_ENCAP_DPORT]        = { .type = NLA_U16 },
1763         [IFLA_IPTUN_FWMARK]             = { .type = NLA_U32 },
1764 };
1765
1766 static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1767 {
1768         struct net *net = dev_net(dev);
1769         struct sit_net *sitn = net_generic(net, sit_net_id);
1770
1771         if (dev != sitn->fb_tunnel_dev)
1772                 unregister_netdevice_queue(dev, head);
1773 }
1774
1775 static struct rtnl_link_ops sit_link_ops __read_mostly = {
1776         .kind           = "sit",
1777         .maxtype        = IFLA_IPTUN_MAX,
1778         .policy         = ipip6_policy,
1779         .priv_size      = sizeof(struct ip_tunnel),
1780         .setup          = ipip6_tunnel_setup,
1781         .validate       = ipip6_validate,
1782         .newlink        = ipip6_newlink,
1783         .changelink     = ipip6_changelink,
1784         .get_size       = ipip6_get_size,
1785         .fill_info      = ipip6_fill_info,
1786         .dellink        = ipip6_dellink,
1787         .get_link_net   = ip_tunnel_get_link_net,
1788 };
1789
1790 static struct xfrm_tunnel sit_handler __read_mostly = {
1791         .handler        =       ipip6_rcv,
1792         .err_handler    =       ipip6_err,
1793         .priority       =       1,
1794 };
1795
1796 static struct xfrm_tunnel ipip_handler __read_mostly = {
1797         .handler        =       ipip_rcv,
1798         .err_handler    =       ipip6_err,
1799         .priority       =       2,
1800 };
1801
1802 #if IS_ENABLED(CONFIG_MPLS)
1803 static struct xfrm_tunnel mplsip_handler __read_mostly = {
1804         .handler        =       mplsip_rcv,
1805         .err_handler    =       ipip6_err,
1806         .priority       =       2,
1807 };
1808 #endif
1809
1810 static void __net_exit sit_destroy_tunnels(struct net *net,
1811                                            struct list_head *head)
1812 {
1813         struct sit_net *sitn = net_generic(net, sit_net_id);
1814         struct net_device *dev, *aux;
1815         int prio;
1816
1817         for_each_netdev_safe(net, dev, aux)
1818                 if (dev->rtnl_link_ops == &sit_link_ops)
1819                         unregister_netdevice_queue(dev, head);
1820
1821         for (prio = 1; prio < 4; prio++) {
1822                 int h;
1823                 for (h = 0; h < IP6_SIT_HASH_SIZE; h++) {
1824                         struct ip_tunnel *t;
1825
1826                         t = rtnl_dereference(sitn->tunnels[prio][h]);
1827                         while (t) {
1828                                 /* If dev is in the same netns, it has already
1829                                  * been added to the list by the previous loop.
1830                                  */
1831                                 if (!net_eq(dev_net(t->dev), net))
1832                                         unregister_netdevice_queue(t->dev,
1833                                                                    head);
1834                                 t = rtnl_dereference(t->next);
1835                         }
1836                 }
1837         }
1838 }
1839
1840 static int __net_init sit_init_net(struct net *net)
1841 {
1842         struct sit_net *sitn = net_generic(net, sit_net_id);
1843         struct ip_tunnel *t;
1844         int err;
1845
1846         sitn->tunnels[0] = sitn->tunnels_wc;
1847         sitn->tunnels[1] = sitn->tunnels_l;
1848         sitn->tunnels[2] = sitn->tunnels_r;
1849         sitn->tunnels[3] = sitn->tunnels_r_l;
1850
1851         if (!net_has_fallback_tunnels(net))
1852                 return 0;
1853
1854         sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1855                                            NET_NAME_UNKNOWN,
1856                                            ipip6_tunnel_setup);
1857         if (!sitn->fb_tunnel_dev) {
1858                 err = -ENOMEM;
1859                 goto err_alloc_dev;
1860         }
1861         dev_net_set(sitn->fb_tunnel_dev, net);
1862         sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1863         /* FB netdevice is special: we have one, and only one per netns.
1864          * Allowing to move it to another netns is clearly unsafe.
1865          */
1866         sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1867
1868         err = register_netdev(sitn->fb_tunnel_dev);
1869         if (err)
1870                 goto err_reg_dev;
1871
1872         ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1873         ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1874
1875         t = netdev_priv(sitn->fb_tunnel_dev);
1876
1877         strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1878         return 0;
1879
1880 err_reg_dev:
1881         ipip6_dev_free(sitn->fb_tunnel_dev);
1882         free_netdev(sitn->fb_tunnel_dev);
1883 err_alloc_dev:
1884         return err;
1885 }
1886
1887 static void __net_exit sit_exit_batch_net(struct list_head *net_list)
1888 {
1889         LIST_HEAD(list);
1890         struct net *net;
1891
1892         rtnl_lock();
1893         list_for_each_entry(net, net_list, exit_list)
1894                 sit_destroy_tunnels(net, &list);
1895
1896         unregister_netdevice_many(&list);
1897         rtnl_unlock();
1898 }
1899
1900 static struct pernet_operations sit_net_ops = {
1901         .init = sit_init_net,
1902         .exit_batch = sit_exit_batch_net,
1903         .id   = &sit_net_id,
1904         .size = sizeof(struct sit_net),
1905 };
1906
1907 static void __exit sit_cleanup(void)
1908 {
1909         rtnl_link_unregister(&sit_link_ops);
1910         xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1911         xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1912 #if IS_ENABLED(CONFIG_MPLS)
1913         xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1914 #endif
1915
1916         unregister_pernet_device(&sit_net_ops);
1917         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1918 }
1919
1920 static int __init sit_init(void)
1921 {
1922         int err;
1923
1924         pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n");
1925
1926         err = register_pernet_device(&sit_net_ops);
1927         if (err < 0)
1928                 return err;
1929         err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1930         if (err < 0) {
1931                 pr_info("%s: can't register ip6ip4\n", __func__);
1932                 goto xfrm_tunnel_failed;
1933         }
1934         err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1935         if (err < 0) {
1936                 pr_info("%s: can't register ip4ip4\n", __func__);
1937                 goto xfrm_tunnel4_failed;
1938         }
1939 #if IS_ENABLED(CONFIG_MPLS)
1940         err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
1941         if (err < 0) {
1942                 pr_info("%s: can't register mplsip\n", __func__);
1943                 goto xfrm_tunnel_mpls_failed;
1944         }
1945 #endif
1946         err = rtnl_link_register(&sit_link_ops);
1947         if (err < 0)
1948                 goto rtnl_link_failed;
1949
1950 out:
1951         return err;
1952
1953 rtnl_link_failed:
1954 #if IS_ENABLED(CONFIG_MPLS)
1955         xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1956 xfrm_tunnel_mpls_failed:
1957 #endif
1958         xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1959 xfrm_tunnel4_failed:
1960         xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1961 xfrm_tunnel_failed:
1962         unregister_pernet_device(&sit_net_ops);
1963         goto out;
1964 }
1965
1966 module_init(sit_init);
1967 module_exit(sit_cleanup);
1968 MODULE_LICENSE("GPL");
1969 MODULE_ALIAS_RTNL_LINK("sit");
1970 MODULE_ALIAS_NETDEV("sit0");