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 static inline struct sit_net *dev_to_sit_net(struct net_device *dev)
  87 {
  88         struct ip_tunnel *t = netdev_priv(dev);
  89
  90         return net_generic(t->net, sit_net_id);
  91 }
  92
  93 /*
  94  * Must be invoked with rcu_read_lock
  95  */
  96 static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
  97                                              struct net_device *dev,
  98                                              __be32 remote, __be32 local,
  99                                              int sifindex)
 100 {
 101         unsigned int h0 = HASH(remote);
 102         unsigned int h1 = HASH(local);
 103         struct ip_tunnel *t;
 104         struct sit_net *sitn = net_generic(net, sit_net_id);
 105         int ifindex = dev ? dev->ifindex : 0;
 106
 107         for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
 108                 if (local == t->parms.iph.saddr &&
 109                     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_r[h0]) {
 116                 if (remote == t->parms.iph.daddr &&
 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         for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
 123                 if (local == t->parms.iph.saddr &&
 124                     (!dev || !t->parms.link || ifindex == t->parms.link ||
 125                      sifindex == t->parms.link) &&
 126                     (t->dev->flags & IFF_UP))
 127                         return t;
 128         }
 129         t = rcu_dereference(sitn->tunnels_wc[0]);
 130         if (t && (t->dev->flags & IFF_UP))
 131                 return t;
 132         return NULL;
 133 }
 134
 135 static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
 136                 struct ip_tunnel_parm *parms)
 137 {
 138         __be32 remote = parms->iph.daddr;
 139         __be32 local = parms->iph.saddr;
 140         unsigned int h = 0;
 141         int prio = 0;
 142
 143         if (remote) {
 144                 prio |= 2;
 145                 h ^= HASH(remote);
 146         }
 147         if (local) {
 148                 prio |= 1;
 149                 h ^= HASH(local);
 150         }
 151         return &sitn->tunnels[prio][h];
 152 }
 153
 154 static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
 155                 struct ip_tunnel *t)
 156 {
 157         return __ipip6_bucket(sitn, &t->parms);
 158 }
 159
 160 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
 161 {
 162         struct ip_tunnel __rcu **tp;
 163         struct ip_tunnel *iter;
 164
 165         for (tp = ipip6_bucket(sitn, t);
 166              (iter = rtnl_dereference(*tp)) != NULL;
 167              tp = &iter->next) {
 168                 if (t == iter) {
 169                         rcu_assign_pointer(*tp, t->next);
 170                         break;
 171                 }
 172         }
 173 }
 174
 175 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
 176 {
 177         struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
 178
 179         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 180         rcu_assign_pointer(*tp, t);
 181 }
 182
 183 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
 184 {
 185 #ifdef CONFIG_IPV6_SIT_6RD
 186         struct ip_tunnel *t = netdev_priv(dev);
 187
 188         if (dev == sitn->fb_tunnel_dev || !sitn->fb_tunnel_dev) {
 189                 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
 190                 t->ip6rd.relay_prefix = 0;
 191                 t->ip6rd.prefixlen = 16;
 192                 t->ip6rd.relay_prefixlen = 0;
 193         } else {
 194                 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
 195                 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
 196         }
 197 #endif
 198 }
 199
 200 static int ipip6_tunnel_create(struct net_device *dev)
 201 {
 202         struct ip_tunnel *t = netdev_priv(dev);
 203         struct net *net = dev_net(dev);
 204         struct sit_net *sitn = net_generic(net, sit_net_id);
 205         int err;
 206
 207         memcpy(dev->dev_addr, &t->parms.iph.saddr, 4);
 208         memcpy(dev->broadcast, &t->parms.iph.daddr, 4);
 209
 210         if ((__force u16)t->parms.i_flags & SIT_ISATAP)
 211                 dev->priv_flags |= IFF_ISATAP;
 212
 213         dev->rtnl_link_ops = &sit_link_ops;
 214
 215         err = register_netdevice(dev);
 216         if (err < 0)
 217                 goto out;
 218
 219         ipip6_tunnel_clone_6rd(dev, sitn);
 220
 221         ipip6_tunnel_link(sitn, t);
 222         return 0;
 223
 224 out:
 225         return err;
 226 }
 227
 228 static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
 229                 struct ip_tunnel_parm *parms, int create)
 230 {
 231         __be32 remote = parms->iph.daddr;
 232         __be32 local = parms->iph.saddr;
 233         struct ip_tunnel *t, *nt;
 234         struct ip_tunnel __rcu **tp;
 235         struct net_device *dev;
 236         char name[IFNAMSIZ];
 237         struct sit_net *sitn = net_generic(net, sit_net_id);
 238
 239         for (tp = __ipip6_bucket(sitn, parms);
 240             (t = rtnl_dereference(*tp)) != NULL;
 241              tp = &t->next) {
 242                 if (local == t->parms.iph.saddr &&
 243                     remote == t->parms.iph.daddr &&
 244                     parms->link == t->parms.link) {
 245                         if (create)
 246                                 return NULL;
 247                         else
 248                                 return t;
 249                 }
 250         }
 251         if (!create)
 252                 goto failed;
 253
 254         if (parms->name[0]) {
 255                 if (!dev_valid_name(parms->name))
 256                         goto failed;
 257                 strlcpy(name, parms->name, IFNAMSIZ);
 258         } else {
 259                 strcpy(name, "sit%d");
 260         }
 261         dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,
 262                            ipip6_tunnel_setup);
 263         if (!dev)
 264                 return NULL;
 265
 266         dev_net_set(dev, net);
 267
 268         nt = netdev_priv(dev);
 269
 270         nt->parms = *parms;
 271         if (ipip6_tunnel_create(dev) < 0)
 272                 goto failed_free;
 273
 274         if (!parms->name[0])
 275                 strcpy(parms->name, dev->name);
 276
 277         return nt;
 278
 279 failed_free:
 280         free_netdev(dev);
 281 failed:
 282         return NULL;
 283 }
 284
 285 #define for_each_prl_rcu(start)                 \
 286         for (prl = rcu_dereference(start);      \
 287              prl;                               \
 288              prl = rcu_dereference(prl->next))
 289
 290 static struct ip_tunnel_prl_entry *
 291 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
 292 {
 293         struct ip_tunnel_prl_entry *prl;
 294
 295         for_each_prl_rcu(t->prl)
 296                 if (prl->addr == addr)
 297                         break;
 298         return prl;
 299
 300 }
 301
 302 static int ipip6_tunnel_get_prl(struct net_device *dev, struct ip_tunnel_prl __user *a)
 303 {
 304         struct ip_tunnel *t = netdev_priv(dev);
 305         struct ip_tunnel_prl kprl, *kp;
 306         struct ip_tunnel_prl_entry *prl;
 307         unsigned int cmax, c = 0, ca, len;
 308         int ret = 0;
 309
 310         if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
 311                 return -EINVAL;
 312
 313         if (copy_from_user(&kprl, a, sizeof(kprl)))
 314                 return -EFAULT;
 315         cmax = kprl.datalen / sizeof(kprl);
 316         if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
 317                 cmax = 1;
 318
 319         /* For simple GET or for root users,
 320          * we try harder to allocate.
 321          */
 322         kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
 323                 kcalloc(cmax, sizeof(*kp), GFP_KERNEL_ACCOUNT | __GFP_NOWARN) :
 324                 NULL;
 325
 326         ca = min(t->prl_count, cmax);
 327
 328         if (!kp) {
 329                 /* We don't try hard to allocate much memory for
 330                  * non-root users.
 331                  * For root users, retry allocating enough memory for
 332                  * the answer.
 333                  */
 334                 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC | __GFP_ACCOUNT |
 335                                               __GFP_NOWARN);
 336                 if (!kp) {
 337                         ret = -ENOMEM;
 338                         goto out;
 339                 }
 340         }
 341
 342         rcu_read_lock();
 343         for_each_prl_rcu(t->prl) {
 344                 if (c >= cmax)
 345                         break;
 346                 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
 347                         continue;
 348                 kp[c].addr = prl->addr;
 349                 kp[c].flags = prl->flags;
 350                 c++;
 351                 if (kprl.addr != htonl(INADDR_ANY))
 352                         break;
 353         }
 354
 355         rcu_read_unlock();
 356
 357         len = sizeof(*kp) * c;
 358         ret = 0;
 359         if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
 360                 ret = -EFAULT;
 361
 362         kfree(kp);
 363 out:
 364         return ret;
 365 }
 366
 367 static int
 368 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
 369 {
 370         struct ip_tunnel_prl_entry *p;
 371         int err = 0;
 372
 373         if (a->addr == htonl(INADDR_ANY))
 374                 return -EINVAL;
 375
 376         ASSERT_RTNL();
 377
 378         for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
 379                 if (p->addr == a->addr) {
 380                         if (chg) {
 381                                 p->flags = a->flags;
 382                                 goto out;
 383                         }
 384                         err = -EEXIST;
 385                         goto out;
 386                 }
 387         }
 388
 389         if (chg) {
 390                 err = -ENXIO;
 391                 goto out;
 392         }
 393
 394         p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
 395         if (!p) {
 396                 err = -ENOBUFS;
 397                 goto out;
 398         }
 399
 400         p->next = t->prl;
 401         p->addr = a->addr;
 402         p->flags = a->flags;
 403         t->prl_count++;
 404         rcu_assign_pointer(t->prl, p);
 405 out:
 406         return err;
 407 }
 408
 409 static void prl_list_destroy_rcu(struct rcu_head *head)
 410 {
 411         struct ip_tunnel_prl_entry *p, *n;
 412
 413         p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
 414         do {
 415                 n = rcu_dereference_protected(p->next, 1);
 416                 kfree(p);
 417                 p = n;
 418         } while (p);
 419 }
 420
 421 static int
 422 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
 423 {
 424         struct ip_tunnel_prl_entry *x;
 425         struct ip_tunnel_prl_entry __rcu **p;
 426         int err = 0;
 427
 428         ASSERT_RTNL();
 429
 430         if (a && a->addr != htonl(INADDR_ANY)) {
 431                 for (p = &t->prl;
 432                      (x = rtnl_dereference(*p)) != NULL;
 433                      p = &x->next) {
 434                         if (x->addr == a->addr) {
 435                                 *p = x->next;
 436                                 kfree_rcu(x, rcu_head);
 437                                 t->prl_count--;
 438                                 goto out;
 439                         }
 440                 }
 441                 err = -ENXIO;
 442         } else {
 443                 x = rtnl_dereference(t->prl);
 444                 if (x) {
 445                         t->prl_count = 0;
 446                         call_rcu(&x->rcu_head, prl_list_destroy_rcu);
 447                         t->prl = NULL;
 448                 }
 449         }
 450 out:
 451         return err;
 452 }
 453
 454 static int ipip6_tunnel_prl_ctl(struct net_device *dev,
 455                                 struct ip_tunnel_prl __user *data, int cmd)
 456 {
 457         struct ip_tunnel *t = netdev_priv(dev);
 458         struct ip_tunnel_prl prl;
 459         int err;
 460
 461         if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
 462                 return -EPERM;
 463         if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
 464                 return -EINVAL;
 465
 466         if (copy_from_user(&prl, data, sizeof(prl)))
 467                 return -EFAULT;
 468
 469         switch (cmd) {
 470         case SIOCDELPRL:
 471                 err = ipip6_tunnel_del_prl(t, &prl);
 472                 break;
 473         case SIOCADDPRL:
 474         case SIOCCHGPRL:
 475                 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
 476                 break;
 477         }
 478         dst_cache_reset(&t->dst_cache);
 479         netdev_state_change(dev);
 480         return err;
 481 }
 482
 483 static int
 484 isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
 485 {
 486         struct ip_tunnel_prl_entry *p;
 487         int ok = 1;
 488
 489         rcu_read_lock();
 490         p = __ipip6_tunnel_locate_prl(t, iph->saddr);
 491         if (p) {
 492                 if (p->flags & PRL_DEFAULT)
 493                         skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
 494                 else
 495                         skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
 496         } else {
 497                 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
 498
 499                 if (ipv6_addr_is_isatap(addr6) &&
 500                     (addr6->s6_addr32[3] == iph->saddr) &&
 501                     ipv6_chk_prefix(addr6, t->dev))
 502                         skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
 503                 else
 504                         ok = 0;
 505         }
 506         rcu_read_unlock();
 507         return ok;
 508 }
 509
 510 static void ipip6_tunnel_uninit(struct net_device *dev)
 511 {
 512         struct ip_tunnel *tunnel = netdev_priv(dev);
 513         struct sit_net *sitn = net_generic(tunnel->net, sit_net_id);
 514
 515         if (dev == sitn->fb_tunnel_dev) {
 516                 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
 517         } else {
 518                 ipip6_tunnel_unlink(sitn, tunnel);
 519                 ipip6_tunnel_del_prl(tunnel, NULL);
 520         }
 521         dst_cache_reset(&tunnel->dst_cache);
 522         dev_put(dev);
 523 }
 524
 525 static int ipip6_err(struct sk_buff *skb, u32 info)
 526 {
 527         const struct iphdr *iph = (const struct iphdr *)skb->data;
 528         const int type = icmp_hdr(skb)->type;
 529         const int code = icmp_hdr(skb)->code;
 530         unsigned int data_len = 0;
 531         struct ip_tunnel *t;
 532         int sifindex;
 533         int err;
 534
 535         switch (type) {
 536         default:
 537         case ICMP_PARAMETERPROB:
 538                 return 0;
 539
 540         case ICMP_DEST_UNREACH:
 541                 switch (code) {
 542                 case ICMP_SR_FAILED:
 543                         /* Impossible event. */
 544                         return 0;
 545                 default:
 546                         /* All others are translated to HOST_UNREACH.
 547                            rfc2003 contains "deep thoughts" about NET_UNREACH,
 548                            I believe they are just ether pollution. --ANK
 549                          */
 550                         break;
 551                 }
 552                 break;
 553         case ICMP_TIME_EXCEEDED:
 554                 if (code != ICMP_EXC_TTL)
 555                         return 0;
 556                 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
 557                 break;
 558         case ICMP_REDIRECT:
 559                 break;
 560         }
 561
 562         err = -ENOENT;
 563
 564         sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
 565         t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 566                                 iph->daddr, iph->saddr, sifindex);
 567         if (!t)
 568                 goto out;
 569
 570         if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
 571                 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
 572                                  t->parms.link, iph->protocol);
 573                 err = 0;
 574                 goto out;
 575         }
 576         if (type == ICMP_REDIRECT) {
 577                 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link,
 578                               iph->protocol);
 579                 err = 0;
 580                 goto out;
 581         }
 582
 583         err = 0;
 584         if (__in6_dev_get(skb->dev) &&
 585             !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len))
 586                 goto out;
 587
 588         if (t->parms.iph.daddr == 0)
 589                 goto out;
 590
 591         if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
 592                 goto out;
 593
 594         if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
 595                 t->err_count++;
 596         else
 597                 t->err_count = 1;
 598         t->err_time = jiffies;
 599 out:
 600         return err;
 601 }
 602
 603 static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
 604                                   const struct in6_addr *v6addr)
 605 {
 606         __be32 v4embed = 0;
 607         if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
 608                 return true;
 609         return false;
 610 }
 611
 612 /* Checks if an address matches an address on the tunnel interface.
 613  * Used to detect the NAT of proto 41 packets and let them pass spoofing test.
 614  * Long story:
 615  * This function is called after we considered the packet as spoofed
 616  * in is_spoofed_6rd.
 617  * We may have a router that is doing NAT for proto 41 packets
 618  * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb
 619  * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd
 620  * function will return true, dropping the packet.
 621  * But, we can still check if is spoofed against the IP
 622  * addresses associated with the interface.
 623  */
 624 static bool only_dnatted(const struct ip_tunnel *tunnel,
 625         const struct in6_addr *v6dst)
 626 {
 627         int prefix_len;
 628
 629 #ifdef CONFIG_IPV6_SIT_6RD
 630         prefix_len = tunnel->ip6rd.prefixlen + 32
 631                 - tunnel->ip6rd.relay_prefixlen;
 632 #else
 633         prefix_len = 48;
 634 #endif
 635         return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev);
 636 }
 637
 638 /* Returns true if a packet is spoofed */
 639 static bool packet_is_spoofed(struct sk_buff *skb,
 640                               const struct iphdr *iph,
 641                               struct ip_tunnel *tunnel)
 642 {
 643         const struct ipv6hdr *ipv6h;
 644
 645         if (tunnel->dev->priv_flags & IFF_ISATAP) {
 646                 if (!isatap_chksrc(skb, iph, tunnel))
 647                         return true;
 648
 649                 return false;
 650         }
 651
 652         if (tunnel->dev->flags & IFF_POINTOPOINT)
 653                 return false;
 654
 655         ipv6h = ipv6_hdr(skb);
 656
 657         if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) {
 658                 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
 659                                      &iph->saddr, &ipv6h->saddr,
 660                                      &iph->daddr, &ipv6h->daddr);
 661                 return true;
 662         }
 663
 664         if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr)))
 665                 return false;
 666
 667         if (only_dnatted(tunnel, &ipv6h->daddr))
 668                 return false;
 669
 670         net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n",
 671                              &iph->saddr, &ipv6h->saddr,
 672                              &iph->daddr, &ipv6h->daddr);
 673         return true;
 674 }
 675
 676 static int ipip6_rcv(struct sk_buff *skb)
 677 {
 678         const struct iphdr *iph = ip_hdr(skb);
 679         struct ip_tunnel *tunnel;
 680         int sifindex;
 681         int err;
 682
 683         sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
 684         tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 685                                      iph->saddr, iph->daddr, sifindex);
 686         if (tunnel) {
 687                 struct pcpu_sw_netstats *tstats;
 688
 689                 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 &&
 690                     tunnel->parms.iph.protocol != 0)
 691                         goto out;
 692
 693                 skb->mac_header = skb->network_header;
 694                 skb_reset_network_header(skb);
 695                 IPCB(skb)->flags = 0;
 696                 skb->dev = tunnel->dev;
 697
 698                 if (packet_is_spoofed(skb, iph, tunnel)) {
 699                         DEV_STATS_INC(tunnel->dev, rx_errors);
 700                         goto out;
 701                 }
 702
 703                 if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6),
 704                     !net_eq(tunnel->net, dev_net(tunnel->dev))))
 705                         goto out;
 706
 707                 /* skb can be uncloned in iptunnel_pull_header, so
 708                  * old iph is no longer valid
 709                  */
 710                 iph = (const struct iphdr *)skb_mac_header(skb);
 711                 skb_reset_mac_header(skb);
 712
 713                 err = IP_ECN_decapsulate(iph, skb);
 714                 if (unlikely(err)) {
 715                         if (log_ecn_error)
 716                                 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
 717                                                      &iph->saddr, iph->tos);
 718                         if (err > 1) {
 719                                 DEV_STATS_INC(tunnel->dev, rx_frame_errors);
 720                                 DEV_STATS_INC(tunnel->dev, rx_errors);
 721                                 goto out;
 722                         }
 723                 }
 724
 725                 tstats = this_cpu_ptr(tunnel->dev->tstats);
 726                 u64_stats_update_begin(&tstats->syncp);
 727                 tstats->rx_packets++;
 728                 tstats->rx_bytes += skb->len;
 729                 u64_stats_update_end(&tstats->syncp);
 730
 731                 netif_rx(skb);
 732
 733                 return 0;
 734         }
 735
 736         /* no tunnel matched,  let upstream know, ipsec may handle it */
 737         return 1;
 738 out:
 739         kfree_skb(skb);
 740         return 0;
 741 }
 742
 743 static const struct tnl_ptk_info ipip_tpi = {
 744         /* no tunnel info required for ipip. */
 745         .proto = htons(ETH_P_IP),
 746 };
 747
 748 #if IS_ENABLED(CONFIG_MPLS)
 749 static const struct tnl_ptk_info mplsip_tpi = {
 750         /* no tunnel info required for mplsip. */
 751         .proto = htons(ETH_P_MPLS_UC),
 752 };
 753 #endif
 754
 755 static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto)
 756 {
 757         const struct iphdr *iph;
 758         struct ip_tunnel *tunnel;
 759         int sifindex;
 760
 761         sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0;
 762
 763         iph = ip_hdr(skb);
 764         tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 765                                      iph->saddr, iph->daddr, sifindex);
 766         if (tunnel) {
 767                 const struct tnl_ptk_info *tpi;
 768
 769                 if (tunnel->parms.iph.protocol != ipproto &&
 770                     tunnel->parms.iph.protocol != 0)
 771                         goto drop;
 772
 773                 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
 774                         goto drop;
 775 #if IS_ENABLED(CONFIG_MPLS)
 776                 if (ipproto == IPPROTO_MPLS)
 777                         tpi = &mplsip_tpi;
 778                 else
 779 #endif
 780                         tpi = &ipip_tpi;
 781                 if (iptunnel_pull_header(skb, 0, tpi->proto, false))
 782                         goto drop;
 783                 skb_reset_mac_header(skb);
 784
 785                 return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error);
 786         }
 787
 788         return 1;
 789
 790 drop:
 791         kfree_skb(skb);
 792         return 0;
 793 }
 794
 795 static int ipip_rcv(struct sk_buff *skb)
 796 {
 797         return sit_tunnel_rcv(skb, IPPROTO_IPIP);
 798 }
 799
 800 #if IS_ENABLED(CONFIG_MPLS)
 801 static int mplsip_rcv(struct sk_buff *skb)
 802 {
 803         return sit_tunnel_rcv(skb, IPPROTO_MPLS);
 804 }
 805 #endif
 806
 807 /*
 808  * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
 809  * stores the embedded IPv4 address in v4dst and returns true.
 810  */
 811 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
 812                       __be32 *v4dst)
 813 {
 814 #ifdef CONFIG_IPV6_SIT_6RD
 815         if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
 816                               tunnel->ip6rd.prefixlen)) {
 817                 unsigned int pbw0, pbi0;
 818                 int pbi1;
 819                 u32 d;
 820
 821                 pbw0 = tunnel->ip6rd.prefixlen >> 5;
 822                 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
 823
 824                 d = tunnel->ip6rd.relay_prefixlen < 32 ?
 825                         (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
 826                     tunnel->ip6rd.relay_prefixlen : 0;
 827
 828                 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
 829                 if (pbi1 > 0)
 830                         d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
 831                              (32 - pbi1);
 832
 833                 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
 834                 return true;
 835         }
 836 #else
 837         if (v6dst->s6_addr16[0] == htons(0x2002)) {
 838                 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
 839                 memcpy(v4dst, &v6dst->s6_addr16[1], 4);
 840                 return true;
 841         }
 842 #endif
 843         return false;
 844 }
 845
 846 static inline __be32 try_6rd(struct ip_tunnel *tunnel,
 847                              const struct in6_addr *v6dst)
 848 {
 849         __be32 dst = 0;
 850         check_6rd(tunnel, v6dst, &dst);
 851         return dst;
 852 }
 853
 854 /*
 855  *      This function assumes it is being called from dev_queue_xmit()
 856  *      and that skb is filled properly by that function.
 857  */
 858
 859 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 860                                      struct net_device *dev)
 861 {
 862         struct ip_tunnel *tunnel = netdev_priv(dev);
 863         const struct iphdr  *tiph = &tunnel->parms.iph;
 864         const struct ipv6hdr *iph6 = ipv6_hdr(skb);
 865         u8     tos = tunnel->parms.iph.tos;
 866         __be16 df = tiph->frag_off;
 867         struct rtable *rt;              /* Route to the other host */
 868         struct net_device *tdev;        /* Device to other host */
 869         unsigned int max_headroom;      /* The extra header space needed */
 870         __be32 dst = tiph->daddr;
 871         struct flowi4 fl4;
 872         int    mtu;
 873         const struct in6_addr *addr6;
 874         int addr_type;
 875         u8 ttl;
 876         u8 protocol = IPPROTO_IPV6;
 877         int t_hlen = tunnel->hlen + sizeof(struct iphdr);
 878
 879         if (tos == 1)
 880                 tos = ipv6_get_dsfield(iph6);
 881
 882         /* ISATAP (RFC4214) - must come before 6to4 */
 883         if (dev->priv_flags & IFF_ISATAP) {
 884                 struct neighbour *neigh = NULL;
 885                 bool do_tx_error = false;
 886
 887                 if (skb_dst(skb))
 888                         neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 889
 890                 if (!neigh) {
 891                         net_dbg_ratelimited("nexthop == NULL\n");
 892                         goto tx_error;
 893                 }
 894
 895                 addr6 = (const struct in6_addr *)&neigh->primary_key;
 896                 addr_type = ipv6_addr_type(addr6);
 897
 898                 if ((addr_type & IPV6_ADDR_UNICAST) &&
 899                      ipv6_addr_is_isatap(addr6))
 900                         dst = addr6->s6_addr32[3];
 901                 else
 902                         do_tx_error = true;
 903
 904                 neigh_release(neigh);
 905                 if (do_tx_error)
 906                         goto tx_error;
 907         }
 908
 909         if (!dst)
 910                 dst = try_6rd(tunnel, &iph6->daddr);
 911
 912         if (!dst) {
 913                 struct neighbour *neigh = NULL;
 914                 bool do_tx_error = false;
 915
 916                 if (skb_dst(skb))
 917                         neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 918
 919                 if (!neigh) {
 920                         net_dbg_ratelimited("nexthop == NULL\n");
 921                         goto tx_error;
 922                 }
 923
 924                 addr6 = (const struct in6_addr *)&neigh->primary_key;
 925                 addr_type = ipv6_addr_type(addr6);
 926
 927                 if (addr_type == IPV6_ADDR_ANY) {
 928                         addr6 = &ipv6_hdr(skb)->daddr;
 929                         addr_type = ipv6_addr_type(addr6);
 930                 }
 931
 932                 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
 933                         dst = addr6->s6_addr32[3];
 934                 else
 935                         do_tx_error = true;
 936
 937                 neigh_release(neigh);
 938                 if (do_tx_error)
 939                         goto tx_error;
 940         }
 941
 942         flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark,
 943                            RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6,
 944                            0, dst, tiph->saddr, 0, 0,
 945                            sock_net_uid(tunnel->net, NULL));
 946
 947         rt = dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr);
 948         if (!rt) {
 949                 rt = ip_route_output_flow(tunnel->net, &fl4, NULL);
 950                 if (IS_ERR(rt)) {
 951                         DEV_STATS_INC(dev, tx_carrier_errors);
 952                         goto tx_error_icmp;
 953                 }
 954                 dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, fl4.saddr);
 955         }
 956
 957         if (rt->rt_type != RTN_UNICAST) {
 958                 ip_rt_put(rt);
 959                 DEV_STATS_INC(dev, tx_carrier_errors);
 960                 goto tx_error_icmp;
 961         }
 962         tdev = rt->dst.dev;
 963
 964         if (tdev == dev) {
 965                 ip_rt_put(rt);
 966                 DEV_STATS_INC(dev, collisions);
 967                 goto tx_error;
 968         }
 969
 970         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) {
 971                 ip_rt_put(rt);
 972                 goto tx_error;
 973         }
 974
 975         if (df) {
 976                 mtu = dst_mtu(&rt->dst) - t_hlen;
 977
 978                 if (mtu < IPV4_MIN_MTU) {
 979                         DEV_STATS_INC(dev, collisions);
 980                         ip_rt_put(rt);
 981                         goto tx_error;
 982                 }
 983
 984                 if (mtu < IPV6_MIN_MTU) {
 985                         mtu = IPV6_MIN_MTU;
 986                         df = 0;
 987                 }
 988
 989                 if (tunnel->parms.iph.daddr)
 990                         skb_dst_update_pmtu_no_confirm(skb, mtu);
 991
 992                 if (skb->len > mtu && !skb_is_gso(skb)) {
 993                         icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 994                         ip_rt_put(rt);
 995                         goto tx_error;
 996                 }
 997         }
 998
 999         if (tunnel->err_count > 0) {
1000                 if (time_before(jiffies,
1001                                 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
1002                         tunnel->err_count--;
1003                         dst_link_failure(skb);
1004                 } else
1005                         tunnel->err_count = 0;
1006         }
1007
1008         /*
1009          * Okay, now see if we can stuff it in the buffer as-is.
1010          */
1011         max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen;
1012
1013         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
1014             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
1015                 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
1016                 if (!new_skb) {
1017                         ip_rt_put(rt);
1018                         DEV_STATS_INC(dev, tx_dropped);
1019                         kfree_skb(skb);
1020                         return NETDEV_TX_OK;
1021                 }
1022                 if (skb->sk)
1023                         skb_set_owner_w(new_skb, skb->sk);
1024                 dev_kfree_skb(skb);
1025                 skb = new_skb;
1026                 iph6 = ipv6_hdr(skb);
1027         }
1028         ttl = tiph->ttl;
1029         if (ttl == 0)
1030                 ttl = iph6->hop_limit;
1031         tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
1032
1033         if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) {
1034                 ip_rt_put(rt);
1035                 goto tx_error;
1036         }
1037
1038         skb_set_inner_ipproto(skb, IPPROTO_IPV6);
1039
1040         iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl,
1041                       df, !net_eq(tunnel->net, dev_net(dev)));
1042         return NETDEV_TX_OK;
1043
1044 tx_error_icmp:
1045         dst_link_failure(skb);
1046 tx_error:
1047         kfree_skb(skb);
1048         DEV_STATS_INC(dev, tx_errors);
1049         return NETDEV_TX_OK;
1050 }
1051
1052 static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb,
1053                                      struct net_device *dev, u8 ipproto)
1054 {
1055         struct ip_tunnel *tunnel = netdev_priv(dev);
1056         const struct iphdr  *tiph = &tunnel->parms.iph;
1057
1058         if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4))
1059                 goto tx_error;
1060
1061         skb_set_inner_ipproto(skb, ipproto);
1062
1063         ip_tunnel_xmit(skb, dev, tiph, ipproto);
1064         return NETDEV_TX_OK;
1065 tx_error:
1066         kfree_skb(skb);
1067         DEV_STATS_INC(dev, tx_errors);
1068         return NETDEV_TX_OK;
1069 }
1070
1071 static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
1072                                    struct net_device *dev)
1073 {
1074         if (!pskb_inet_may_pull(skb))
1075                 goto tx_err;
1076
1077         switch (skb->protocol) {
1078         case htons(ETH_P_IP):
1079                 sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP);
1080                 break;
1081         case htons(ETH_P_IPV6):
1082                 ipip6_tunnel_xmit(skb, dev);
1083                 break;
1084 #if IS_ENABLED(CONFIG_MPLS)
1085         case htons(ETH_P_MPLS_UC):
1086                 sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS);
1087                 break;
1088 #endif
1089         default:
1090                 goto tx_err;
1091         }
1092
1093         return NETDEV_TX_OK;
1094
1095 tx_err:
1096         DEV_STATS_INC(dev, tx_errors);
1097         kfree_skb(skb);
1098         return NETDEV_TX_OK;
1099
1100 }
1101
1102 static void ipip6_tunnel_bind_dev(struct net_device *dev)
1103 {
1104         struct ip_tunnel *tunnel = netdev_priv(dev);
1105         int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1106         struct net_device *tdev = NULL;
1107         int hlen = LL_MAX_HEADER;
1108         const struct iphdr *iph;
1109         struct flowi4 fl4;
1110
1111         iph = &tunnel->parms.iph;
1112
1113         if (iph->daddr) {
1114                 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4,
1115                                                           NULL,
1116                                                           iph->daddr, iph->saddr,
1117                                                           0, 0,
1118                                                           IPPROTO_IPV6,
1119                                                           RT_TOS(iph->tos),
1120                                                           tunnel->parms.link);
1121
1122                 if (!IS_ERR(rt)) {
1123                         tdev = rt->dst.dev;
1124                         ip_rt_put(rt);
1125                 }
1126                 dev->flags |= IFF_POINTOPOINT;
1127         }
1128
1129         if (!tdev && tunnel->parms.link)
1130                 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
1131
1132         if (tdev && !netif_is_l3_master(tdev)) {
1133                 int mtu;
1134
1135                 mtu = tdev->mtu - t_hlen;
1136                 if (mtu < IPV6_MIN_MTU)
1137                         mtu = IPV6_MIN_MTU;
1138                 WRITE_ONCE(dev->mtu, mtu);
1139                 hlen = tdev->hard_header_len + tdev->needed_headroom;
1140         }
1141         dev->needed_headroom = t_hlen + hlen;
1142 }
1143
1144 static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p,
1145                                 __u32 fwmark)
1146 {
1147         struct net *net = t->net;
1148         struct sit_net *sitn = net_generic(net, sit_net_id);
1149
1150         ipip6_tunnel_unlink(sitn, t);
1151         synchronize_net();
1152         t->parms.iph.saddr = p->iph.saddr;
1153         t->parms.iph.daddr = p->iph.daddr;
1154         memcpy(t->dev->dev_addr, &p->iph.saddr, 4);
1155         memcpy(t->dev->broadcast, &p->iph.daddr, 4);
1156         ipip6_tunnel_link(sitn, t);
1157         t->parms.iph.ttl = p->iph.ttl;
1158         t->parms.iph.tos = p->iph.tos;
1159         t->parms.iph.frag_off = p->iph.frag_off;
1160         if (t->parms.link != p->link || t->fwmark != fwmark) {
1161                 t->parms.link = p->link;
1162                 t->fwmark = fwmark;
1163                 ipip6_tunnel_bind_dev(t->dev);
1164         }
1165         dst_cache_reset(&t->dst_cache);
1166         netdev_state_change(t->dev);
1167 }
1168
1169 #ifdef CONFIG_IPV6_SIT_6RD
1170 static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
1171                                    struct ip_tunnel_6rd *ip6rd)
1172 {
1173         struct in6_addr prefix;
1174         __be32 relay_prefix;
1175
1176         if (ip6rd->relay_prefixlen > 32 ||
1177             ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
1178                 return -EINVAL;
1179
1180         ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
1181         if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
1182                 return -EINVAL;
1183         if (ip6rd->relay_prefixlen)
1184                 relay_prefix = ip6rd->relay_prefix &
1185                                htonl(0xffffffffUL <<
1186                                      (32 - ip6rd->relay_prefixlen));
1187         else
1188                 relay_prefix = 0;
1189         if (relay_prefix != ip6rd->relay_prefix)
1190                 return -EINVAL;
1191
1192         t->ip6rd.prefix = prefix;
1193         t->ip6rd.relay_prefix = relay_prefix;
1194         t->ip6rd.prefixlen = ip6rd->prefixlen;
1195         t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
1196         dst_cache_reset(&t->dst_cache);
1197         netdev_state_change(t->dev);
1198         return 0;
1199 }
1200
1201 static int
1202 ipip6_tunnel_get6rd(struct net_device *dev, struct ip_tunnel_parm __user *data)
1203 {
1204         struct ip_tunnel *t = netdev_priv(dev);
1205         struct ip_tunnel_6rd ip6rd;
1206         struct ip_tunnel_parm p;
1207
1208         if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1209                 if (copy_from_user(&p, data, sizeof(p)))
1210                         return -EFAULT;
1211                 t = ipip6_tunnel_locate(t->net, &p, 0);
1212         }
1213         if (!t)
1214                 t = netdev_priv(dev);
1215
1216         ip6rd.prefix = t->ip6rd.prefix;
1217         ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1218         ip6rd.prefixlen = t->ip6rd.prefixlen;
1219         ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1220         if (copy_to_user(data, &ip6rd, sizeof(ip6rd)))
1221                 return -EFAULT;
1222         return 0;
1223 }
1224
1225 static int
1226 ipip6_tunnel_6rdctl(struct net_device *dev, struct ip_tunnel_6rd __user *data,
1227                     int cmd)
1228 {
1229         struct ip_tunnel *t = netdev_priv(dev);
1230         struct ip_tunnel_6rd ip6rd;
1231         int err;
1232
1233         if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
1234                 return -EPERM;
1235         if (copy_from_user(&ip6rd, data, sizeof(ip6rd)))
1236                 return -EFAULT;
1237
1238         if (cmd != SIOCDEL6RD) {
1239                 err = ipip6_tunnel_update_6rd(t, &ip6rd);
1240                 if (err < 0)
1241                         return err;
1242         } else
1243                 ipip6_tunnel_clone_6rd(dev, dev_to_sit_net(dev));
1244         return 0;
1245 }
1246
1247 #endif /* CONFIG_IPV6_SIT_6RD */
1248
1249 static bool ipip6_valid_ip_proto(u8 ipproto)
1250 {
1251         return ipproto == IPPROTO_IPV6 ||
1252                 ipproto == IPPROTO_IPIP ||
1253 #if IS_ENABLED(CONFIG_MPLS)
1254                 ipproto == IPPROTO_MPLS ||
1255 #endif
1256                 ipproto == 0;
1257 }
1258
1259 static int
1260 __ipip6_tunnel_ioctl_validate(struct net *net, struct ip_tunnel_parm *p)
1261 {
1262         if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1263                 return -EPERM;
1264
1265         if (!ipip6_valid_ip_proto(p->iph.protocol))
1266                 return -EINVAL;
1267         if (p->iph.version != 4 ||
1268             p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF)))
1269                 return -EINVAL;
1270
1271         if (p->iph.ttl)
1272                 p->iph.frag_off |= htons(IP_DF);
1273         return 0;
1274 }
1275
1276 static int
1277 ipip6_tunnel_get(struct net_device *dev, struct ip_tunnel_parm *p)
1278 {
1279         struct ip_tunnel *t = netdev_priv(dev);
1280
1281         if (dev == dev_to_sit_net(dev)->fb_tunnel_dev)
1282                 t = ipip6_tunnel_locate(t->net, p, 0);
1283         if (!t)
1284                 t = netdev_priv(dev);
1285         memcpy(p, &t->parms, sizeof(*p));
1286         return 0;
1287 }
1288
1289 static int
1290 ipip6_tunnel_add(struct net_device *dev, struct ip_tunnel_parm *p)
1291 {
1292         struct ip_tunnel *t = netdev_priv(dev);
1293         int err;
1294
1295         err = __ipip6_tunnel_ioctl_validate(t->net, p);
1296         if (err)
1297                 return err;
1298
1299         t = ipip6_tunnel_locate(t->net, p, 1);
1300         if (!t)
1301                 return -ENOBUFS;
1302         return 0;
1303 }
1304
1305 static int
1306 ipip6_tunnel_change(struct net_device *dev, struct ip_tunnel_parm *p)
1307 {
1308         struct ip_tunnel *t = netdev_priv(dev);
1309         int err;
1310
1311         err = __ipip6_tunnel_ioctl_validate(t->net, p);
1312         if (err)
1313                 return err;
1314
1315         t = ipip6_tunnel_locate(t->net, p, 0);
1316         if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1317                 if (!t)
1318                         return -ENOENT;
1319         } else {
1320                 if (t) {
1321                         if (t->dev != dev)
1322                                 return -EEXIST;
1323                 } else {
1324                         if (((dev->flags & IFF_POINTOPOINT) && !p->iph.daddr) ||
1325                             (!(dev->flags & IFF_POINTOPOINT) && p->iph.daddr))
1326                                 return -EINVAL;
1327                         t = netdev_priv(dev);
1328                 }
1329
1330                 ipip6_tunnel_update(t, p, t->fwmark);
1331         }
1332
1333         return 0;
1334 }
1335
1336 static int
1337 ipip6_tunnel_del(struct net_device *dev, struct ip_tunnel_parm *p)
1338 {
1339         struct ip_tunnel *t = netdev_priv(dev);
1340
1341         if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN))
1342                 return -EPERM;
1343
1344         if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) {
1345                 t = ipip6_tunnel_locate(t->net, p, 0);
1346                 if (!t)
1347                         return -ENOENT;
1348                 if (t == netdev_priv(dev_to_sit_net(dev)->fb_tunnel_dev))
1349                         return -EPERM;
1350                 dev = t->dev;
1351         }
1352         unregister_netdevice(dev);
1353         return 0;
1354 }
1355
1356 static int
1357 ipip6_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd)
1358 {
1359         switch (cmd) {
1360         case SIOCGETTUNNEL:
1361                 return ipip6_tunnel_get(dev, p);
1362         case SIOCADDTUNNEL:
1363                 return ipip6_tunnel_add(dev, p);
1364         case SIOCCHGTUNNEL:
1365                 return ipip6_tunnel_change(dev, p);
1366         case SIOCDELTUNNEL:
1367                 return ipip6_tunnel_del(dev, p);
1368         default:
1369                 return -EINVAL;
1370         }
1371 }
1372
1373 static int
1374 ipip6_tunnel_siocdevprivate(struct net_device *dev, struct ifreq *ifr,
1375                             void __user *data, int cmd)
1376 {
1377         switch (cmd) {
1378         case SIOCGETTUNNEL:
1379         case SIOCADDTUNNEL:
1380         case SIOCCHGTUNNEL:
1381         case SIOCDELTUNNEL:
1382                 return ip_tunnel_siocdevprivate(dev, ifr, data, cmd);
1383         case SIOCGETPRL:
1384                 return ipip6_tunnel_get_prl(dev, data);
1385         case SIOCADDPRL:
1386         case SIOCDELPRL:
1387         case SIOCCHGPRL:
1388                 return ipip6_tunnel_prl_ctl(dev, data, cmd);
1389 #ifdef CONFIG_IPV6_SIT_6RD
1390         case SIOCGET6RD:
1391                 return ipip6_tunnel_get6rd(dev, data);
1392         case SIOCADD6RD:
1393         case SIOCCHG6RD:
1394         case SIOCDEL6RD:
1395                 return ipip6_tunnel_6rdctl(dev, data, cmd);
1396 #endif
1397         default:
1398                 return -EINVAL;
1399         }
1400 }
1401
1402 static const struct net_device_ops ipip6_netdev_ops = {
1403         .ndo_init       = ipip6_tunnel_init,
1404         .ndo_uninit     = ipip6_tunnel_uninit,
1405         .ndo_start_xmit = sit_tunnel_xmit,
1406         .ndo_siocdevprivate = ipip6_tunnel_siocdevprivate,
1407         .ndo_get_stats64 = dev_get_tstats64,
1408         .ndo_get_iflink = ip_tunnel_get_iflink,
1409         .ndo_tunnel_ctl = ipip6_tunnel_ctl,
1410 };
1411
1412 static void ipip6_dev_free(struct net_device *dev)
1413 {
1414         struct ip_tunnel *tunnel = netdev_priv(dev);
1415
1416         dst_cache_destroy(&tunnel->dst_cache);
1417         free_percpu(dev->tstats);
1418 }
1419
1420 #define SIT_FEATURES (NETIF_F_SG           | \
1421                       NETIF_F_FRAGLIST     | \
1422                       NETIF_F_HIGHDMA      | \
1423                       NETIF_F_GSO_SOFTWARE | \
1424                       NETIF_F_HW_CSUM)
1425
1426 static void ipip6_tunnel_setup(struct net_device *dev)
1427 {
1428         struct ip_tunnel *tunnel = netdev_priv(dev);
1429         int t_hlen = tunnel->hlen + sizeof(struct iphdr);
1430
1431         dev->netdev_ops         = &ipip6_netdev_ops;
1432         dev->header_ops         = &ip_tunnel_header_ops;
1433         dev->needs_free_netdev  = true;
1434         dev->priv_destructor    = ipip6_dev_free;
1435
1436         dev->type               = ARPHRD_SIT;
1437         dev->mtu                = ETH_DATA_LEN - t_hlen;
1438         dev->min_mtu            = IPV6_MIN_MTU;
1439         dev->max_mtu            = IP6_MAX_MTU - t_hlen;
1440         dev->flags              = IFF_NOARP;
1441         netif_keep_dst(dev);
1442         dev->addr_len           = 4;
1443         dev->features           |= NETIF_F_LLTX;
1444         dev->features           |= SIT_FEATURES;
1445         dev->hw_features        |= SIT_FEATURES;
1446 }
1447
1448 static int ipip6_tunnel_init(struct net_device *dev)
1449 {
1450         struct ip_tunnel *tunnel = netdev_priv(dev);
1451         int err;
1452
1453         tunnel->dev = dev;
1454         tunnel->net = dev_net(dev);
1455         strcpy(tunnel->parms.name, dev->name);
1456
1457         ipip6_tunnel_bind_dev(dev);
1458         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
1459         if (!dev->tstats)
1460                 return -ENOMEM;
1461
1462         err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);
1463         if (err) {
1464                 free_percpu(dev->tstats);
1465                 dev->tstats = NULL;
1466                 return err;
1467         }
1468         dev_hold(dev);
1469         return 0;
1470 }
1471
1472 static void __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1473 {
1474         struct ip_tunnel *tunnel = netdev_priv(dev);
1475         struct iphdr *iph = &tunnel->parms.iph;
1476         struct net *net = dev_net(dev);
1477         struct sit_net *sitn = net_generic(net, sit_net_id);
1478
1479         iph->version            = 4;
1480         iph->protocol           = IPPROTO_IPV6;
1481         iph->ihl                = 5;
1482         iph->ttl                = 64;
1483
1484         rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1485 }
1486
1487 static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[],
1488                           struct netlink_ext_ack *extack)
1489 {
1490         u8 proto;
1491
1492         if (!data || !data[IFLA_IPTUN_PROTO])
1493                 return 0;
1494
1495         proto = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1496         if (!ipip6_valid_ip_proto(proto))
1497                 return -EINVAL;
1498
1499         return 0;
1500 }
1501
1502 static void ipip6_netlink_parms(struct nlattr *data[],
1503                                 struct ip_tunnel_parm *parms,
1504                                 __u32 *fwmark)
1505 {
1506         memset(parms, 0, sizeof(*parms));
1507
1508         parms->iph.version = 4;
1509         parms->iph.protocol = IPPROTO_IPV6;
1510         parms->iph.ihl = 5;
1511         parms->iph.ttl = 64;
1512
1513         if (!data)
1514                 return;
1515
1516         if (data[IFLA_IPTUN_LINK])
1517                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1518
1519         if (data[IFLA_IPTUN_LOCAL])
1520                 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1521
1522         if (data[IFLA_IPTUN_REMOTE])
1523                 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1524
1525         if (data[IFLA_IPTUN_TTL]) {
1526                 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1527                 if (parms->iph.ttl)
1528                         parms->iph.frag_off = htons(IP_DF);
1529         }
1530
1531         if (data[IFLA_IPTUN_TOS])
1532                 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1533
1534         if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1535                 parms->iph.frag_off = htons(IP_DF);
1536
1537         if (data[IFLA_IPTUN_FLAGS])
1538                 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1539
1540         if (data[IFLA_IPTUN_PROTO])
1541                 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
1542
1543         if (data[IFLA_IPTUN_FWMARK])
1544                 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]);
1545 }
1546
1547 /* This function returns true when ENCAP attributes are present in the nl msg */
1548 static bool ipip6_netlink_encap_parms(struct nlattr *data[],
1549                                       struct ip_tunnel_encap *ipencap)
1550 {
1551         bool ret = false;
1552
1553         memset(ipencap, 0, sizeof(*ipencap));
1554
1555         if (!data)
1556                 return ret;
1557
1558         if (data[IFLA_IPTUN_ENCAP_TYPE]) {
1559                 ret = true;
1560                 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
1561         }
1562
1563         if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
1564                 ret = true;
1565                 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
1566         }
1567
1568         if (data[IFLA_IPTUN_ENCAP_SPORT]) {
1569                 ret = true;
1570                 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
1571         }
1572
1573         if (data[IFLA_IPTUN_ENCAP_DPORT]) {
1574                 ret = true;
1575                 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
1576         }
1577
1578         return ret;
1579 }
1580
1581 #ifdef CONFIG_IPV6_SIT_6RD
1582 /* This function returns true when 6RD attributes are present in the nl msg */
1583 static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1584                                     struct ip_tunnel_6rd *ip6rd)
1585 {
1586         bool ret = false;
1587         memset(ip6rd, 0, sizeof(*ip6rd));
1588
1589         if (!data)
1590                 return ret;
1591
1592         if (data[IFLA_IPTUN_6RD_PREFIX]) {
1593                 ret = true;
1594                 ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]);
1595         }
1596
1597         if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1598                 ret = true;
1599                 ip6rd->relay_prefix =
1600                         nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1601         }
1602
1603         if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1604                 ret = true;
1605                 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1606         }
1607
1608         if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1609                 ret = true;
1610                 ip6rd->relay_prefixlen =
1611                         nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1612         }
1613
1614         return ret;
1615 }
1616 #endif
1617
1618 static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1619                          struct nlattr *tb[], struct nlattr *data[],
1620                          struct netlink_ext_ack *extack)
1621 {
1622         struct net *net = dev_net(dev);
1623         struct ip_tunnel *nt;
1624         struct ip_tunnel_encap ipencap;
1625 #ifdef CONFIG_IPV6_SIT_6RD
1626         struct ip_tunnel_6rd ip6rd;
1627 #endif
1628         int err;
1629
1630         nt = netdev_priv(dev);
1631
1632         if (ipip6_netlink_encap_parms(data, &ipencap)) {
1633                 err = ip_tunnel_encap_setup(nt, &ipencap);
1634                 if (err < 0)
1635                         return err;
1636         }
1637
1638         ipip6_netlink_parms(data, &nt->parms, &nt->fwmark);
1639
1640         if (ipip6_tunnel_locate(net, &nt->parms, 0))
1641                 return -EEXIST;
1642
1643         err = ipip6_tunnel_create(dev);
1644         if (err < 0)
1645                 return err;
1646
1647         if (tb[IFLA_MTU]) {
1648                 u32 mtu = nla_get_u32(tb[IFLA_MTU]);
1649
1650                 if (mtu >= IPV6_MIN_MTU &&
1651                     mtu <= IP6_MAX_MTU - dev->hard_header_len)
1652                         dev->mtu = mtu;
1653         }
1654
1655 #ifdef CONFIG_IPV6_SIT_6RD
1656         if (ipip6_netlink_6rd_parms(data, &ip6rd)) {
1657                 err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1658                 if (err < 0)
1659                         unregister_netdevice_queue(dev, NULL);
1660         }
1661 #endif
1662
1663         return err;
1664 }
1665
1666 static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1667                             struct nlattr *data[],
1668                             struct netlink_ext_ack *extack)
1669 {
1670         struct ip_tunnel *t = netdev_priv(dev);
1671         struct ip_tunnel_parm p;
1672         struct ip_tunnel_encap ipencap;
1673         struct net *net = t->net;
1674         struct sit_net *sitn = net_generic(net, sit_net_id);
1675 #ifdef CONFIG_IPV6_SIT_6RD
1676         struct ip_tunnel_6rd ip6rd;
1677 #endif
1678         __u32 fwmark = t->fwmark;
1679         int err;
1680
1681         if (dev == sitn->fb_tunnel_dev)
1682                 return -EINVAL;
1683
1684         if (ipip6_netlink_encap_parms(data, &ipencap)) {
1685                 err = ip_tunnel_encap_setup(t, &ipencap);
1686                 if (err < 0)
1687                         return err;
1688         }
1689
1690         ipip6_netlink_parms(data, &p, &fwmark);
1691
1692         if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1693             (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1694                 return -EINVAL;
1695
1696         t = ipip6_tunnel_locate(net, &p, 0);
1697
1698         if (t) {
1699                 if (t->dev != dev)
1700                         return -EEXIST;
1701         } else
1702                 t = netdev_priv(dev);
1703
1704         ipip6_tunnel_update(t, &p, fwmark);
1705
1706 #ifdef CONFIG_IPV6_SIT_6RD
1707         if (ipip6_netlink_6rd_parms(data, &ip6rd))
1708                 return ipip6_tunnel_update_6rd(t, &ip6rd);
1709 #endif
1710
1711         return 0;
1712 }
1713
1714 static size_t ipip6_get_size(const struct net_device *dev)
1715 {
1716         return
1717                 /* IFLA_IPTUN_LINK */
1718                 nla_total_size(4) +
1719                 /* IFLA_IPTUN_LOCAL */
1720                 nla_total_size(4) +
1721                 /* IFLA_IPTUN_REMOTE */
1722                 nla_total_size(4) +
1723                 /* IFLA_IPTUN_TTL */
1724                 nla_total_size(1) +
1725                 /* IFLA_IPTUN_TOS */
1726                 nla_total_size(1) +
1727                 /* IFLA_IPTUN_PMTUDISC */
1728                 nla_total_size(1) +
1729                 /* IFLA_IPTUN_FLAGS */
1730                 nla_total_size(2) +
1731                 /* IFLA_IPTUN_PROTO */
1732                 nla_total_size(1) +
1733 #ifdef CONFIG_IPV6_SIT_6RD
1734                 /* IFLA_IPTUN_6RD_PREFIX */
1735                 nla_total_size(sizeof(struct in6_addr)) +
1736                 /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1737                 nla_total_size(4) +
1738                 /* IFLA_IPTUN_6RD_PREFIXLEN */
1739                 nla_total_size(2) +
1740                 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1741                 nla_total_size(2) +
1742 #endif
1743                 /* IFLA_IPTUN_ENCAP_TYPE */
1744                 nla_total_size(2) +
1745                 /* IFLA_IPTUN_ENCAP_FLAGS */
1746                 nla_total_size(2) +
1747                 /* IFLA_IPTUN_ENCAP_SPORT */
1748                 nla_total_size(2) +
1749                 /* IFLA_IPTUN_ENCAP_DPORT */
1750                 nla_total_size(2) +
1751                 /* IFLA_IPTUN_FWMARK */
1752                 nla_total_size(4) +
1753                 0;
1754 }
1755
1756 static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1757 {
1758         struct ip_tunnel *tunnel = netdev_priv(dev);
1759         struct ip_tunnel_parm *parm = &tunnel->parms;
1760
1761         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1762             nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1763             nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1764             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1765             nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1766             nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1767                        !!(parm->iph.frag_off & htons(IP_DF))) ||
1768             nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) ||
1769             nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags) ||
1770             nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark))
1771                 goto nla_put_failure;
1772
1773 #ifdef CONFIG_IPV6_SIT_6RD
1774         if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX,
1775                              &tunnel->ip6rd.prefix) ||
1776             nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1777                             tunnel->ip6rd.relay_prefix) ||
1778             nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1779                         tunnel->ip6rd.prefixlen) ||
1780             nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1781                         tunnel->ip6rd.relay_prefixlen))
1782                 goto nla_put_failure;
1783 #endif
1784
1785         if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE,
1786                         tunnel->encap.type) ||
1787             nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT,
1788                         tunnel->encap.sport) ||
1789             nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT,
1790                         tunnel->encap.dport) ||
1791             nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS,
1792                         tunnel->encap.flags))
1793                 goto nla_put_failure;
1794
1795         return 0;
1796
1797 nla_put_failure:
1798         return -EMSGSIZE;
1799 }
1800
1801 static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1802         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
1803         [IFLA_IPTUN_LOCAL]              = { .type = NLA_U32 },
1804         [IFLA_IPTUN_REMOTE]             = { .type = NLA_U32 },
1805         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
1806         [IFLA_IPTUN_TOS]                = { .type = NLA_U8 },
1807         [IFLA_IPTUN_PMTUDISC]           = { .type = NLA_U8 },
1808         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U16 },
1809         [IFLA_IPTUN_PROTO]              = { .type = NLA_U8 },
1810 #ifdef CONFIG_IPV6_SIT_6RD
1811         [IFLA_IPTUN_6RD_PREFIX]         = { .len = sizeof(struct in6_addr) },
1812         [IFLA_IPTUN_6RD_RELAY_PREFIX]   = { .type = NLA_U32 },
1813         [IFLA_IPTUN_6RD_PREFIXLEN]      = { .type = NLA_U16 },
1814         [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1815 #endif
1816         [IFLA_IPTUN_ENCAP_TYPE]         = { .type = NLA_U16 },
1817         [IFLA_IPTUN_ENCAP_FLAGS]        = { .type = NLA_U16 },
1818         [IFLA_IPTUN_ENCAP_SPORT]        = { .type = NLA_U16 },
1819         [IFLA_IPTUN_ENCAP_DPORT]        = { .type = NLA_U16 },
1820         [IFLA_IPTUN_FWMARK]             = { .type = NLA_U32 },
1821 };
1822
1823 static void ipip6_dellink(struct net_device *dev, struct list_head *head)
1824 {
1825         struct net *net = dev_net(dev);
1826         struct sit_net *sitn = net_generic(net, sit_net_id);
1827
1828         if (dev != sitn->fb_tunnel_dev)
1829                 unregister_netdevice_queue(dev, head);
1830 }
1831
1832 static struct rtnl_link_ops sit_link_ops __read_mostly = {
1833         .kind           = "sit",
1834         .maxtype        = IFLA_IPTUN_MAX,
1835         .policy         = ipip6_policy,
1836         .priv_size      = sizeof(struct ip_tunnel),
1837         .setup          = ipip6_tunnel_setup,
1838         .validate       = ipip6_validate,
1839         .newlink        = ipip6_newlink,
1840         .changelink     = ipip6_changelink,
1841         .get_size       = ipip6_get_size,
1842         .fill_info      = ipip6_fill_info,
1843         .dellink        = ipip6_dellink,
1844         .get_link_net   = ip_tunnel_get_link_net,
1845 };
1846
1847 static struct xfrm_tunnel sit_handler __read_mostly = {
1848         .handler        =       ipip6_rcv,
1849         .err_handler    =       ipip6_err,
1850         .priority       =       1,
1851 };
1852
1853 static struct xfrm_tunnel ipip_handler __read_mostly = {
1854         .handler        =       ipip_rcv,
1855         .err_handler    =       ipip6_err,
1856         .priority       =       2,
1857 };
1858
1859 #if IS_ENABLED(CONFIG_MPLS)
1860 static struct xfrm_tunnel mplsip_handler __read_mostly = {
1861         .handler        =       mplsip_rcv,
1862         .err_handler    =       ipip6_err,
1863         .priority       =       2,
1864 };
1865 #endif
1866
1867 static void __net_exit sit_destroy_tunnels(struct net *net,
1868                                            struct list_head *head)
1869 {
1870         struct sit_net *sitn = net_generic(net, sit_net_id);
1871         struct net_device *dev, *aux;
1872         int prio;
1873
1874         for_each_netdev_safe(net, dev, aux)
1875                 if (dev->rtnl_link_ops == &sit_link_ops)
1876                         unregister_netdevice_queue(dev, head);
1877
1878         for (prio = 0; prio < 4; prio++) {
1879                 int h;
1880                 for (h = 0; h < (prio ? IP6_SIT_HASH_SIZE : 1); h++) {
1881                         struct ip_tunnel *t;
1882
1883                         t = rtnl_dereference(sitn->tunnels[prio][h]);
1884                         while (t) {
1885                                 /* If dev is in the same netns, it has already
1886                                  * been added to the list by the previous loop.
1887                                  */
1888                                 if (!net_eq(dev_net(t->dev), net))
1889                                         unregister_netdevice_queue(t->dev,
1890                                                                    head);
1891                                 t = rtnl_dereference(t->next);
1892                         }
1893                 }
1894         }
1895 }
1896
1897 static int __net_init sit_init_net(struct net *net)
1898 {
1899         struct sit_net *sitn = net_generic(net, sit_net_id);
1900         struct ip_tunnel *t;
1901         int err;
1902
1903         sitn->tunnels[0] = sitn->tunnels_wc;
1904         sitn->tunnels[1] = sitn->tunnels_l;
1905         sitn->tunnels[2] = sitn->tunnels_r;
1906         sitn->tunnels[3] = sitn->tunnels_r_l;
1907
1908         if (!net_has_fallback_tunnels(net))
1909                 return 0;
1910
1911         sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1912                                            NET_NAME_UNKNOWN,
1913                                            ipip6_tunnel_setup);
1914         if (!sitn->fb_tunnel_dev) {
1915                 err = -ENOMEM;
1916                 goto err_alloc_dev;
1917         }
1918         dev_net_set(sitn->fb_tunnel_dev, net);
1919         sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops;
1920         /* FB netdevice is special: we have one, and only one per netns.
1921          * Allowing to move it to another netns is clearly unsafe.
1922          */
1923         sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL;
1924
1925         err = register_netdev(sitn->fb_tunnel_dev);
1926         if (err)
1927                 goto err_reg_dev;
1928
1929         ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1930         ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1931
1932         t = netdev_priv(sitn->fb_tunnel_dev);
1933
1934         strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1935         return 0;
1936
1937 err_reg_dev:
1938         free_netdev(sitn->fb_tunnel_dev);
1939 err_alloc_dev:
1940         return err;
1941 }
1942
1943 static void __net_exit sit_exit_batch_net(struct list_head *net_list)
1944 {
1945         LIST_HEAD(list);
1946         struct net *net;
1947
1948         rtnl_lock();
1949         list_for_each_entry(net, net_list, exit_list)
1950                 sit_destroy_tunnels(net, &list);
1951
1952         unregister_netdevice_many(&list);
1953         rtnl_unlock();
1954 }
1955
1956 static struct pernet_operations sit_net_ops = {
1957         .init = sit_init_net,
1958         .exit_batch = sit_exit_batch_net,
1959         .id   = &sit_net_id,
1960         .size = sizeof(struct sit_net),
1961 };
1962
1963 static void __exit sit_cleanup(void)
1964 {
1965         rtnl_link_unregister(&sit_link_ops);
1966         xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1967         xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
1968 #if IS_ENABLED(CONFIG_MPLS)
1969         xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
1970 #endif
1971
1972         unregister_pernet_device(&sit_net_ops);
1973         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1974 }
1975
1976 static int __init sit_init(void)
1977 {
1978         int err;
1979
1980         pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n");
1981
1982         err = register_pernet_device(&sit_net_ops);
1983         if (err < 0)
1984                 return err;
1985         err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1986         if (err < 0) {
1987                 pr_info("%s: can't register ip6ip4\n", __func__);
1988                 goto xfrm_tunnel_failed;
1989         }
1990         err = xfrm4_tunnel_register(&ipip_handler, AF_INET);
1991         if (err < 0) {
1992                 pr_info("%s: can't register ip4ip4\n", __func__);
1993                 goto xfrm_tunnel4_failed;
1994         }
1995 #if IS_ENABLED(CONFIG_MPLS)
1996         err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS);
1997         if (err < 0) {
1998                 pr_info("%s: can't register mplsip\n", __func__);
1999                 goto xfrm_tunnel_mpls_failed;
2000         }
2001 #endif
2002         err = rtnl_link_register(&sit_link_ops);
2003         if (err < 0)
2004                 goto rtnl_link_failed;
2005
2006 out:
2007         return err;
2008
2009 rtnl_link_failed:
2010 #if IS_ENABLED(CONFIG_MPLS)
2011         xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS);
2012 xfrm_tunnel_mpls_failed:
2013 #endif
2014         xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
2015 xfrm_tunnel4_failed:
2016         xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
2017 xfrm_tunnel_failed:
2018         unregister_pernet_device(&sit_net_ops);
2019         goto out;
2020 }
2021
2022 module_init(sit_init);
2023 module_exit(sit_cleanup);
2024 MODULE_LICENSE("GPL");
2025 MODULE_ALIAS_RTNL_LINK("sit");
2026 MODULE_ALIAS_NETDEV("sit0");