net/ipv6/sit.c

   1 /*
   2  *      IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT)
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *      Alexey Kuznetsov        <kuznet@ms2.inr.ac.ru>
   8  *
   9  *      This program is free software; you can redistribute it and/or
  10  *      modify it under the terms of the GNU General Public License
  11  *      as published by the Free Software Foundation; either version
  12  *      2 of the License, or (at your option) any later version.
  13  *
  14  *      Changes:
  15  * Roger Venning <r.venning@telstra.com>:       6to4 support
  16  * Nate Thompson <nate@thebog.net>:             6to4 support
  17  * Fred Templin <fred.l.templin@boeing.com>:    isatap support
  18  */
  19
  20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  21
  22 #include <linux/module.h>
  23 #include <linux/capability.h>
  24 #include <linux/errno.h>
  25 #include <linux/types.h>
  26 #include <linux/socket.h>
  27 #include <linux/sockios.h>
  28 #include <linux/net.h>
  29 #include <linux/in6.h>
  30 #include <linux/netdevice.h>
  31 #include <linux/if_arp.h>
  32 #include <linux/icmp.h>
  33 #include <linux/slab.h>
  34 #include <asm/uaccess.h>
  35 #include <linux/init.h>
  36 #include <linux/netfilter_ipv4.h>
  37 #include <linux/if_ether.h>
  38
  39 #include <net/sock.h>
  40 #include <net/snmp.h>
  41
  42 #include <net/ipv6.h>
  43 #include <net/protocol.h>
  44 #include <net/transp_v6.h>
  45 #include <net/ip6_fib.h>
  46 #include <net/ip6_route.h>
  47 #include <net/ndisc.h>
  48 #include <net/addrconf.h>
  49 #include <net/ip.h>
  50 #include <net/udp.h>
  51 #include <net/icmp.h>
  52 #include <net/ipip.h>
  53 #include <net/inet_ecn.h>
  54 #include <net/xfrm.h>
  55 #include <net/dsfield.h>
  56 #include <net/net_namespace.h>
  57 #include <net/netns/generic.h>
  58
  59 /*
  60    This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c
  61
  62    For comments look at net/ipv4/ip_gre.c --ANK
  63  */
  64
  65 #define HASH_SIZE  16
  66 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
  67
  68 static 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 struct rtnl_link_ops sit_link_ops __read_mostly;
  72
  73 static int sit_net_id __read_mostly;
  74 struct sit_net {
  75         struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE];
  76         struct ip_tunnel __rcu *tunnels_r[HASH_SIZE];
  77         struct ip_tunnel __rcu *tunnels_l[HASH_SIZE];
  78         struct ip_tunnel __rcu *tunnels_wc[1];
  79         struct ip_tunnel __rcu **tunnels[4];
  80
  81         struct net_device *fb_tunnel_dev;
  82 };
  83
  84 static struct rtnl_link_stats64 *ipip6_get_stats64(struct net_device *dev,
  85                                                    struct rtnl_link_stats64 *tot)
  86 {
  87         int i;
  88
  89         for_each_possible_cpu(i) {
  90                 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
  91                 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
  92                 unsigned int start;
  93
  94                 do {
  95                         start = u64_stats_fetch_begin_bh(&tstats->syncp);
  96                         rx_packets = tstats->rx_packets;
  97                         tx_packets = tstats->tx_packets;
  98                         rx_bytes = tstats->rx_bytes;
  99                         tx_bytes = tstats->tx_bytes;
 100                 } while (u64_stats_fetch_retry_bh(&tstats->syncp, start));
 101
 102                 tot->rx_packets += rx_packets;
 103                 tot->tx_packets += tx_packets;
 104                 tot->rx_bytes   += rx_bytes;
 105                 tot->tx_bytes   += tx_bytes;
 106         }
 107
 108         tot->rx_errors = dev->stats.rx_errors;
 109         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
 110         tot->tx_carrier_errors = dev->stats.tx_carrier_errors;
 111         tot->tx_dropped = dev->stats.tx_dropped;
 112         tot->tx_aborted_errors = dev->stats.tx_aborted_errors;
 113         tot->tx_errors = dev->stats.tx_errors;
 114
 115         return tot;
 116 }
 117
 118 /*
 119  * Must be invoked with rcu_read_lock
 120  */
 121 static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
 122                 struct net_device *dev, __be32 remote, __be32 local)
 123 {
 124         unsigned int h0 = HASH(remote);
 125         unsigned int h1 = HASH(local);
 126         struct ip_tunnel *t;
 127         struct sit_net *sitn = net_generic(net, sit_net_id);
 128
 129         for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
 130                 if (local == t->parms.iph.saddr &&
 131                     remote == t->parms.iph.daddr &&
 132                     (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
 133                     (t->dev->flags & IFF_UP))
 134                         return t;
 135         }
 136         for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) {
 137                 if (remote == t->parms.iph.daddr &&
 138                     (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
 139                     (t->dev->flags & IFF_UP))
 140                         return t;
 141         }
 142         for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
 143                 if (local == t->parms.iph.saddr &&
 144                     (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
 145                     (t->dev->flags & IFF_UP))
 146                         return t;
 147         }
 148         t = rcu_dereference(sitn->tunnels_wc[0]);
 149         if ((t != NULL) && (t->dev->flags & IFF_UP))
 150                 return t;
 151         return NULL;
 152 }
 153
 154 static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
 155                 struct ip_tunnel_parm *parms)
 156 {
 157         __be32 remote = parms->iph.daddr;
 158         __be32 local = parms->iph.saddr;
 159         unsigned int h = 0;
 160         int prio = 0;
 161
 162         if (remote) {
 163                 prio |= 2;
 164                 h ^= HASH(remote);
 165         }
 166         if (local) {
 167                 prio |= 1;
 168                 h ^= HASH(local);
 169         }
 170         return &sitn->tunnels[prio][h];
 171 }
 172
 173 static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
 174                 struct ip_tunnel *t)
 175 {
 176         return __ipip6_bucket(sitn, &t->parms);
 177 }
 178
 179 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
 180 {
 181         struct ip_tunnel __rcu **tp;
 182         struct ip_tunnel *iter;
 183
 184         for (tp = ipip6_bucket(sitn, t);
 185              (iter = rtnl_dereference(*tp)) != NULL;
 186              tp = &iter->next) {
 187                 if (t == iter) {
 188                         rcu_assign_pointer(*tp, t->next);
 189                         break;
 190                 }
 191         }
 192 }
 193
 194 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
 195 {
 196         struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
 197
 198         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 199         rcu_assign_pointer(*tp, t);
 200 }
 201
 202 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
 203 {
 204 #ifdef CONFIG_IPV6_SIT_6RD
 205         struct ip_tunnel *t = netdev_priv(dev);
 206
 207         if (t->dev == sitn->fb_tunnel_dev) {
 208                 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
 209                 t->ip6rd.relay_prefix = 0;
 210                 t->ip6rd.prefixlen = 16;
 211                 t->ip6rd.relay_prefixlen = 0;
 212         } else {
 213                 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
 214                 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
 215         }
 216 #endif
 217 }
 218
 219 static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
 220                 struct ip_tunnel_parm *parms, int create)
 221 {
 222         __be32 remote = parms->iph.daddr;
 223         __be32 local = parms->iph.saddr;
 224         struct ip_tunnel *t, *nt;
 225         struct ip_tunnel __rcu **tp;
 226         struct net_device *dev;
 227         char name[IFNAMSIZ];
 228         struct sit_net *sitn = net_generic(net, sit_net_id);
 229
 230         for (tp = __ipip6_bucket(sitn, parms);
 231             (t = rtnl_dereference(*tp)) != NULL;
 232              tp = &t->next) {
 233                 if (local == t->parms.iph.saddr &&
 234                     remote == t->parms.iph.daddr &&
 235                     parms->link == t->parms.link) {
 236                         if (create)
 237                                 return NULL;
 238                         else
 239                                 return t;
 240                 }
 241         }
 242         if (!create)
 243                 goto failed;
 244
 245         if (parms->name[0])
 246                 strlcpy(name, parms->name, IFNAMSIZ);
 247         else
 248                 strcpy(name, "sit%d");
 249
 250         dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup);
 251         if (dev == NULL)
 252                 return NULL;
 253
 254         dev_net_set(dev, net);
 255
 256         nt = netdev_priv(dev);
 257
 258         nt->parms = *parms;
 259         if (ipip6_tunnel_init(dev) < 0)
 260                 goto failed_free;
 261         ipip6_tunnel_clone_6rd(dev, sitn);
 262
 263         if (parms->i_flags & SIT_ISATAP)
 264                 dev->priv_flags |= IFF_ISATAP;
 265
 266         if (register_netdevice(dev) < 0)
 267                 goto failed_free;
 268
 269         strcpy(nt->parms.name, dev->name);
 270         dev->rtnl_link_ops = &sit_link_ops;
 271
 272         dev_hold(dev);
 273
 274         ipip6_tunnel_link(sitn, nt);
 275         return nt;
 276
 277 failed_free:
 278         ipip6_dev_free(dev);
 279 failed:
 280         return NULL;
 281 }
 282
 283 #define for_each_prl_rcu(start)                 \
 284         for (prl = rcu_dereference(start);      \
 285              prl;                               \
 286              prl = rcu_dereference(prl->next))
 287
 288 static struct ip_tunnel_prl_entry *
 289 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
 290 {
 291         struct ip_tunnel_prl_entry *prl;
 292
 293         for_each_prl_rcu(t->prl)
 294                 if (prl->addr == addr)
 295                         break;
 296         return prl;
 297
 298 }
 299
 300 static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
 301                                 struct ip_tunnel_prl __user *a)
 302 {
 303         struct ip_tunnel_prl kprl, *kp;
 304         struct ip_tunnel_prl_entry *prl;
 305         unsigned int cmax, c = 0, ca, len;
 306         int ret = 0;
 307
 308         if (copy_from_user(&kprl, a, sizeof(kprl)))
 309                 return -EFAULT;
 310         cmax = kprl.datalen / sizeof(kprl);
 311         if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
 312                 cmax = 1;
 313
 314         /* For simple GET or for root users,
 315          * we try harder to allocate.
 316          */
 317         kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
 318                 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
 319                 NULL;
 320
 321         rcu_read_lock();
 322
 323         ca = t->prl_count < cmax ? t->prl_count : cmax;
 324
 325         if (!kp) {
 326                 /* We don't try hard to allocate much memory for
 327                  * non-root users.
 328                  * For root users, retry allocating enough memory for
 329                  * the answer.
 330                  */
 331                 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
 332                 if (!kp) {
 333                         ret = -ENOMEM;
 334                         goto out;
 335                 }
 336         }
 337
 338         c = 0;
 339         for_each_prl_rcu(t->prl) {
 340                 if (c >= cmax)
 341                         break;
 342                 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
 343                         continue;
 344                 kp[c].addr = prl->addr;
 345                 kp[c].flags = prl->flags;
 346                 c++;
 347                 if (kprl.addr != htonl(INADDR_ANY))
 348                         break;
 349         }
 350 out:
 351         rcu_read_unlock();
 352
 353         len = sizeof(*kp) * c;
 354         ret = 0;
 355         if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
 356                 ret = -EFAULT;
 357
 358         kfree(kp);
 359
 360         return ret;
 361 }
 362
 363 static int
 364 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
 365 {
 366         struct ip_tunnel_prl_entry *p;
 367         int err = 0;
 368
 369         if (a->addr == htonl(INADDR_ANY))
 370                 return -EINVAL;
 371
 372         ASSERT_RTNL();
 373
 374         for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
 375                 if (p->addr == a->addr) {
 376                         if (chg) {
 377                                 p->flags = a->flags;
 378                                 goto out;
 379                         }
 380                         err = -EEXIST;
 381                         goto out;
 382                 }
 383         }
 384
 385         if (chg) {
 386                 err = -ENXIO;
 387                 goto out;
 388         }
 389
 390         p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
 391         if (!p) {
 392                 err = -ENOBUFS;
 393                 goto out;
 394         }
 395
 396         p->next = t->prl;
 397         p->addr = a->addr;
 398         p->flags = a->flags;
 399         t->prl_count++;
 400         rcu_assign_pointer(t->prl, p);
 401 out:
 402         return err;
 403 }
 404
 405 static void prl_list_destroy_rcu(struct rcu_head *head)
 406 {
 407         struct ip_tunnel_prl_entry *p, *n;
 408
 409         p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
 410         do {
 411                 n = rcu_dereference_protected(p->next, 1);
 412                 kfree(p);
 413                 p = n;
 414         } while (p);
 415 }
 416
 417 static int
 418 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
 419 {
 420         struct ip_tunnel_prl_entry *x;
 421         struct ip_tunnel_prl_entry __rcu **p;
 422         int err = 0;
 423
 424         ASSERT_RTNL();
 425
 426         if (a && a->addr != htonl(INADDR_ANY)) {
 427                 for (p = &t->prl;
 428                      (x = rtnl_dereference(*p)) != NULL;
 429                      p = &x->next) {
 430                         if (x->addr == a->addr) {
 431                                 *p = x->next;
 432                                 kfree_rcu(x, rcu_head);
 433                                 t->prl_count--;
 434                                 goto out;
 435                         }
 436                 }
 437                 err = -ENXIO;
 438         } else {
 439                 x = rtnl_dereference(t->prl);
 440                 if (x) {
 441                         t->prl_count = 0;
 442                         call_rcu(&x->rcu_head, prl_list_destroy_rcu);
 443                         t->prl = NULL;
 444                 }
 445         }
 446 out:
 447         return err;
 448 }
 449
 450 static int
 451 isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
 452 {
 453         struct ip_tunnel_prl_entry *p;
 454         int ok = 1;
 455
 456         rcu_read_lock();
 457         p = __ipip6_tunnel_locate_prl(t, iph->saddr);
 458         if (p) {
 459                 if (p->flags & PRL_DEFAULT)
 460                         skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
 461                 else
 462                         skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
 463         } else {
 464                 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
 465
 466                 if (ipv6_addr_is_isatap(addr6) &&
 467                     (addr6->s6_addr32[3] == iph->saddr) &&
 468                     ipv6_chk_prefix(addr6, t->dev))
 469                         skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
 470                 else
 471                         ok = 0;
 472         }
 473         rcu_read_unlock();
 474         return ok;
 475 }
 476
 477 static void ipip6_tunnel_uninit(struct net_device *dev)
 478 {
 479         struct net *net = dev_net(dev);
 480         struct sit_net *sitn = net_generic(net, sit_net_id);
 481
 482         if (dev == sitn->fb_tunnel_dev) {
 483                 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
 484         } else {
 485                 ipip6_tunnel_unlink(sitn, netdev_priv(dev));
 486                 ipip6_tunnel_del_prl(netdev_priv(dev), NULL);
 487         }
 488         dev_put(dev);
 489 }
 490
 491
 492 static int ipip6_err(struct sk_buff *skb, u32 info)
 493 {
 494
 495 /* All the routers (except for Linux) return only
 496    8 bytes of packet payload. It means, that precise relaying of
 497    ICMP in the real Internet is absolutely infeasible.
 498  */
 499         const struct iphdr *iph = (const struct iphdr *)skb->data;
 500         const int type = icmp_hdr(skb)->type;
 501         const int code = icmp_hdr(skb)->code;
 502         struct ip_tunnel *t;
 503         int err;
 504
 505         switch (type) {
 506         default:
 507         case ICMP_PARAMETERPROB:
 508                 return 0;
 509
 510         case ICMP_DEST_UNREACH:
 511                 switch (code) {
 512                 case ICMP_SR_FAILED:
 513                 case ICMP_PORT_UNREACH:
 514                         /* Impossible event. */
 515                         return 0;
 516                 default:
 517                         /* All others are translated to HOST_UNREACH.
 518                            rfc2003 contains "deep thoughts" about NET_UNREACH,
 519                            I believe they are just ether pollution. --ANK
 520                          */
 521                         break;
 522                 }
 523                 break;
 524         case ICMP_TIME_EXCEEDED:
 525                 if (code != ICMP_EXC_TTL)
 526                         return 0;
 527                 break;
 528         case ICMP_REDIRECT:
 529                 break;
 530         }
 531
 532         err = -ENOENT;
 533
 534         t = ipip6_tunnel_lookup(dev_net(skb->dev),
 535                                 skb->dev,
 536                                 iph->daddr,
 537                                 iph->saddr);
 538         if (t == NULL)
 539                 goto out;
 540
 541         if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
 542                 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
 543                                  t->dev->ifindex, 0, IPPROTO_IPV6, 0);
 544                 err = 0;
 545                 goto out;
 546         }
 547         if (type == ICMP_REDIRECT) {
 548                 ipv4_redirect(skb, dev_net(skb->dev), t->dev->ifindex, 0,
 549                               IPPROTO_IPV6, 0);
 550                 err = 0;
 551                 goto out;
 552         }
 553
 554         if (t->parms.iph.daddr == 0)
 555                 goto out;
 556
 557         err = 0;
 558         if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
 559                 goto out;
 560
 561         if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
 562                 t->err_count++;
 563         else
 564                 t->err_count = 1;
 565         t->err_time = jiffies;
 566 out:
 567         return err;
 568 }
 569
 570 static inline void ipip6_ecn_decapsulate(const struct iphdr *iph, struct sk_buff *skb)
 571 {
 572         if (INET_ECN_is_ce(iph->tos))
 573                 IP6_ECN_set_ce(ipv6_hdr(skb));
 574 }
 575
 576 static int ipip6_rcv(struct sk_buff *skb)
 577 {
 578         const struct iphdr *iph;
 579         struct ip_tunnel *tunnel;
 580
 581         if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
 582                 goto out;
 583
 584         iph = ip_hdr(skb);
 585
 586         tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 587                                      iph->saddr, iph->daddr);
 588         if (tunnel != NULL) {
 589                 struct pcpu_tstats *tstats;
 590
 591                 secpath_reset(skb);
 592                 skb->mac_header = skb->network_header;
 593                 skb_reset_network_header(skb);
 594                 IPCB(skb)->flags = 0;
 595                 skb->protocol = htons(ETH_P_IPV6);
 596                 skb->pkt_type = PACKET_HOST;
 597
 598                 if ((tunnel->dev->priv_flags & IFF_ISATAP) &&
 599                     !isatap_chksrc(skb, iph, tunnel)) {
 600                         tunnel->dev->stats.rx_errors++;
 601                         kfree_skb(skb);
 602                         return 0;
 603                 }
 604
 605                 tstats = this_cpu_ptr(tunnel->dev->tstats);
 606                 tstats->rx_packets++;
 607                 tstats->rx_bytes += skb->len;
 608
 609                 __skb_tunnel_rx(skb, tunnel->dev);
 610
 611                 ipip6_ecn_decapsulate(iph, skb);
 612
 613                 netif_rx(skb);
 614
 615                 return 0;
 616         }
 617
 618         /* no tunnel matched,  let upstream know, ipsec may handle it */
 619         return 1;
 620 out:
 621         kfree_skb(skb);
 622         return 0;
 623 }
 624
 625 /*
 626  * Returns the embedded IPv4 address if the IPv6 address
 627  * comes from 6rd / 6to4 (RFC 3056) addr space.
 628  */
 629 static inline
 630 __be32 try_6rd(const struct in6_addr *v6dst, struct ip_tunnel *tunnel)
 631 {
 632         __be32 dst = 0;
 633
 634 #ifdef CONFIG_IPV6_SIT_6RD
 635         if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
 636                               tunnel->ip6rd.prefixlen)) {
 637                 unsigned int pbw0, pbi0;
 638                 int pbi1;
 639                 u32 d;
 640
 641                 pbw0 = tunnel->ip6rd.prefixlen >> 5;
 642                 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
 643
 644                 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
 645                     tunnel->ip6rd.relay_prefixlen;
 646
 647                 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
 648                 if (pbi1 > 0)
 649                         d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
 650                              (32 - pbi1);
 651
 652                 dst = tunnel->ip6rd.relay_prefix | htonl(d);
 653         }
 654 #else
 655         if (v6dst->s6_addr16[0] == htons(0x2002)) {
 656                 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
 657                 memcpy(&dst, &v6dst->s6_addr16[1], 4);
 658         }
 659 #endif
 660         return dst;
 661 }
 662
 663 /*
 664  *      This function assumes it is being called from dev_queue_xmit()
 665  *      and that skb is filled properly by that function.
 666  */
 667
 668 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 669                                      struct net_device *dev)
 670 {
 671         struct ip_tunnel *tunnel = netdev_priv(dev);
 672         const struct iphdr  *tiph = &tunnel->parms.iph;
 673         const struct ipv6hdr *iph6 = ipv6_hdr(skb);
 674         u8     tos = tunnel->parms.iph.tos;
 675         __be16 df = tiph->frag_off;
 676         struct rtable *rt;                      /* Route to the other host */
 677         struct net_device *tdev;                /* Device to other host */
 678         struct iphdr  *iph;                     /* Our new IP header */
 679         unsigned int max_headroom;              /* The extra header space needed */
 680         __be32 dst = tiph->daddr;
 681         struct flowi4 fl4;
 682         int    mtu;
 683         const struct in6_addr *addr6;
 684         int addr_type;
 685
 686         if (skb->protocol != htons(ETH_P_IPV6))
 687                 goto tx_error;
 688
 689         if (tos == 1)
 690                 tos = ipv6_get_dsfield(iph6);
 691
 692         /* ISATAP (RFC4214) - must come before 6to4 */
 693         if (dev->priv_flags & IFF_ISATAP) {
 694                 struct neighbour *neigh = NULL;
 695                 bool do_tx_error = false;
 696
 697                 if (skb_dst(skb))
 698                         neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 699
 700                 if (neigh == NULL) {
 701                         net_dbg_ratelimited("sit: nexthop == NULL\n");
 702                         goto tx_error;
 703                 }
 704
 705                 addr6 = (const struct in6_addr *)&neigh->primary_key;
 706                 addr_type = ipv6_addr_type(addr6);
 707
 708                 if ((addr_type & IPV6_ADDR_UNICAST) &&
 709                      ipv6_addr_is_isatap(addr6))
 710                         dst = addr6->s6_addr32[3];
 711                 else
 712                         do_tx_error = true;
 713
 714                 neigh_release(neigh);
 715                 if (do_tx_error)
 716                         goto tx_error;
 717         }
 718
 719         if (!dst)
 720                 dst = try_6rd(&iph6->daddr, tunnel);
 721
 722         if (!dst) {
 723                 struct neighbour *neigh = NULL;
 724                 bool do_tx_error = false;
 725
 726                 if (skb_dst(skb))
 727                         neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 728
 729                 if (neigh == NULL) {
 730                         net_dbg_ratelimited("sit: nexthop == NULL\n");
 731                         goto tx_error;
 732                 }
 733
 734                 addr6 = (const struct in6_addr *)&neigh->primary_key;
 735                 addr_type = ipv6_addr_type(addr6);
 736
 737                 if (addr_type == IPV6_ADDR_ANY) {
 738                         addr6 = &ipv6_hdr(skb)->daddr;
 739                         addr_type = ipv6_addr_type(addr6);
 740                 }
 741
 742                 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
 743                         dst = addr6->s6_addr32[3];
 744                 else
 745                         do_tx_error = true;
 746
 747                 neigh_release(neigh);
 748                 if (do_tx_error)
 749                         goto tx_error;
 750         }
 751
 752         rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
 753                                    dst, tiph->saddr,
 754                                    0, 0,
 755                                    IPPROTO_IPV6, RT_TOS(tos),
 756                                    tunnel->parms.link);
 757         if (IS_ERR(rt)) {
 758                 dev->stats.tx_carrier_errors++;
 759                 goto tx_error_icmp;
 760         }
 761         if (rt->rt_type != RTN_UNICAST) {
 762                 ip_rt_put(rt);
 763                 dev->stats.tx_carrier_errors++;
 764                 goto tx_error_icmp;
 765         }
 766         tdev = rt->dst.dev;
 767
 768         if (tdev == dev) {
 769                 ip_rt_put(rt);
 770                 dev->stats.collisions++;
 771                 goto tx_error;
 772         }
 773
 774         if (df) {
 775                 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
 776
 777                 if (mtu < 68) {
 778                         dev->stats.collisions++;
 779                         ip_rt_put(rt);
 780                         goto tx_error;
 781                 }
 782
 783                 if (mtu < IPV6_MIN_MTU) {
 784                         mtu = IPV6_MIN_MTU;
 785                         df = 0;
 786                 }
 787
 788                 if (tunnel->parms.iph.daddr && skb_dst(skb))
 789                         skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 790
 791                 if (skb->len > mtu) {
 792                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 793                         ip_rt_put(rt);
 794                         goto tx_error;
 795                 }
 796         }
 797
 798         if (tunnel->err_count > 0) {
 799                 if (time_before(jiffies,
 800                                 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
 801                         tunnel->err_count--;
 802                         dst_link_failure(skb);
 803                 } else
 804                         tunnel->err_count = 0;
 805         }
 806
 807         /*
 808          * Okay, now see if we can stuff it in the buffer as-is.
 809          */
 810         max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
 811
 812         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 813             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 814                 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
 815                 if (!new_skb) {
 816                         ip_rt_put(rt);
 817                         dev->stats.tx_dropped++;
 818                         dev_kfree_skb(skb);
 819                         return NETDEV_TX_OK;
 820                 }
 821                 if (skb->sk)
 822                         skb_set_owner_w(new_skb, skb->sk);
 823                 dev_kfree_skb(skb);
 824                 skb = new_skb;
 825                 iph6 = ipv6_hdr(skb);
 826         }
 827
 828         skb->transport_header = skb->network_header;
 829         skb_push(skb, sizeof(struct iphdr));
 830         skb_reset_network_header(skb);
 831         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 832         IPCB(skb)->flags = 0;
 833         skb_dst_drop(skb);
 834         skb_dst_set(skb, &rt->dst);
 835
 836         /*
 837          *      Push down and install the IPIP header.
 838          */
 839
 840         iph                     =       ip_hdr(skb);
 841         iph->version            =       4;
 842         iph->ihl                =       sizeof(struct iphdr)>>2;
 843         iph->frag_off           =       df;
 844         iph->protocol           =       IPPROTO_IPV6;
 845         iph->tos                =       INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
 846         iph->daddr              =       fl4.daddr;
 847         iph->saddr              =       fl4.saddr;
 848
 849         if ((iph->ttl = tiph->ttl) == 0)
 850                 iph->ttl        =       iph6->hop_limit;
 851
 852         iptunnel_xmit(skb, dev);
 853         return NETDEV_TX_OK;
 854
 855 tx_error_icmp:
 856         dst_link_failure(skb);
 857 tx_error:
 858         dev->stats.tx_errors++;
 859         dev_kfree_skb(skb);
 860         return NETDEV_TX_OK;
 861 }
 862
 863 static void ipip6_tunnel_bind_dev(struct net_device *dev)
 864 {
 865         struct net_device *tdev = NULL;
 866         struct ip_tunnel *tunnel;
 867         const struct iphdr *iph;
 868         struct flowi4 fl4;
 869
 870         tunnel = netdev_priv(dev);
 871         iph = &tunnel->parms.iph;
 872
 873         if (iph->daddr) {
 874                 struct rtable *rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
 875                                                           iph->daddr, iph->saddr,
 876                                                           0, 0,
 877                                                           IPPROTO_IPV6,
 878                                                           RT_TOS(iph->tos),
 879                                                           tunnel->parms.link);
 880
 881                 if (!IS_ERR(rt)) {
 882                         tdev = rt->dst.dev;
 883                         ip_rt_put(rt);
 884                 }
 885                 dev->flags |= IFF_POINTOPOINT;
 886         }
 887
 888         if (!tdev && tunnel->parms.link)
 889                 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
 890
 891         if (tdev) {
 892                 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
 893                 dev->mtu = tdev->mtu - sizeof(struct iphdr);
 894                 if (dev->mtu < IPV6_MIN_MTU)
 895                         dev->mtu = IPV6_MIN_MTU;
 896         }
 897         dev->iflink = tunnel->parms.link;
 898 }
 899
 900 static int
 901 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
 902 {
 903         int err = 0;
 904         struct ip_tunnel_parm p;
 905         struct ip_tunnel_prl prl;
 906         struct ip_tunnel *t;
 907         struct net *net = dev_net(dev);
 908         struct sit_net *sitn = net_generic(net, sit_net_id);
 909 #ifdef CONFIG_IPV6_SIT_6RD
 910         struct ip_tunnel_6rd ip6rd;
 911 #endif
 912
 913         switch (cmd) {
 914         case SIOCGETTUNNEL:
 915 #ifdef CONFIG_IPV6_SIT_6RD
 916         case SIOCGET6RD:
 917 #endif
 918                 t = NULL;
 919                 if (dev == sitn->fb_tunnel_dev) {
 920                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
 921                                 err = -EFAULT;
 922                                 break;
 923                         }
 924                         t = ipip6_tunnel_locate(net, &p, 0);
 925                 }
 926                 if (t == NULL)
 927                         t = netdev_priv(dev);
 928
 929                 err = -EFAULT;
 930                 if (cmd == SIOCGETTUNNEL) {
 931                         memcpy(&p, &t->parms, sizeof(p));
 932                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
 933                                          sizeof(p)))
 934                                 goto done;
 935 #ifdef CONFIG_IPV6_SIT_6RD
 936                 } else {
 937                         ip6rd.prefix = t->ip6rd.prefix;
 938                         ip6rd.relay_prefix = t->ip6rd.relay_prefix;
 939                         ip6rd.prefixlen = t->ip6rd.prefixlen;
 940                         ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
 941                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
 942                                          sizeof(ip6rd)))
 943                                 goto done;
 944 #endif
 945                 }
 946                 err = 0;
 947                 break;
 948
 949         case SIOCADDTUNNEL:
 950         case SIOCCHGTUNNEL:
 951                 err = -EPERM;
 952                 if (!capable(CAP_NET_ADMIN))
 953                         goto done;
 954
 955                 err = -EFAULT;
 956                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 957                         goto done;
 958
 959                 err = -EINVAL;
 960                 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
 961                     p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
 962                         goto done;
 963                 if (p.iph.ttl)
 964                         p.iph.frag_off |= htons(IP_DF);
 965
 966                 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
 967
 968                 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
 969                         if (t != NULL) {
 970                                 if (t->dev != dev) {
 971                                         err = -EEXIST;
 972                                         break;
 973                                 }
 974                         } else {
 975                                 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
 976                                     (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
 977                                         err = -EINVAL;
 978                                         break;
 979                                 }
 980                                 t = netdev_priv(dev);
 981                         }
 982
 983                         ipip6_tunnel_unlink(sitn, t);
 984                         synchronize_net();
 985                         t->parms.iph.saddr = p.iph.saddr;
 986                         t->parms.iph.daddr = p.iph.daddr;
 987                         memcpy(dev->dev_addr, &p.iph.saddr, 4);
 988                         memcpy(dev->broadcast, &p.iph.daddr, 4);
 989                         ipip6_tunnel_link(sitn, t);
 990                         t->parms.iph.ttl = p.iph.ttl;
 991                         t->parms.iph.tos = p.iph.tos;
 992                         if (t->parms.link != p.link) {
 993                                 t->parms.link = p.link;
 994                                 ipip6_tunnel_bind_dev(dev);
 995                         }
 996                         netdev_state_change(dev);
 997                 }
 998
 999                 if (t) {
1000                         err = 0;
1001                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1002                                 err = -EFAULT;
1003                 } else
1004                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1005                 break;
1006
1007         case SIOCDELTUNNEL:
1008                 err = -EPERM;
1009                 if (!capable(CAP_NET_ADMIN))
1010                         goto done;
1011
1012                 if (dev == sitn->fb_tunnel_dev) {
1013                         err = -EFAULT;
1014                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1015                                 goto done;
1016                         err = -ENOENT;
1017                         if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
1018                                 goto done;
1019                         err = -EPERM;
1020                         if (t == netdev_priv(sitn->fb_tunnel_dev))
1021                                 goto done;
1022                         dev = t->dev;
1023                 }
1024                 unregister_netdevice(dev);
1025                 err = 0;
1026                 break;
1027
1028         case SIOCGETPRL:
1029                 err = -EINVAL;
1030                 if (dev == sitn->fb_tunnel_dev)
1031                         goto done;
1032                 err = -ENOENT;
1033                 if (!(t = netdev_priv(dev)))
1034                         goto done;
1035                 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1036                 break;
1037
1038         case SIOCADDPRL:
1039         case SIOCDELPRL:
1040         case SIOCCHGPRL:
1041                 err = -EPERM;
1042                 if (!capable(CAP_NET_ADMIN))
1043                         goto done;
1044                 err = -EINVAL;
1045                 if (dev == sitn->fb_tunnel_dev)
1046                         goto done;
1047                 err = -EFAULT;
1048                 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1049                         goto done;
1050                 err = -ENOENT;
1051                 if (!(t = netdev_priv(dev)))
1052                         goto done;
1053
1054                 switch (cmd) {
1055                 case SIOCDELPRL:
1056                         err = ipip6_tunnel_del_prl(t, &prl);
1057                         break;
1058                 case SIOCADDPRL:
1059                 case SIOCCHGPRL:
1060                         err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1061                         break;
1062                 }
1063                 netdev_state_change(dev);
1064                 break;
1065
1066 #ifdef CONFIG_IPV6_SIT_6RD
1067         case SIOCADD6RD:
1068         case SIOCCHG6RD:
1069         case SIOCDEL6RD:
1070                 err = -EPERM;
1071                 if (!capable(CAP_NET_ADMIN))
1072                         goto done;
1073
1074                 err = -EFAULT;
1075                 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1076                                    sizeof(ip6rd)))
1077                         goto done;
1078
1079                 t = netdev_priv(dev);
1080
1081                 if (cmd != SIOCDEL6RD) {
1082                         struct in6_addr prefix;
1083                         __be32 relay_prefix;
1084
1085                         err = -EINVAL;
1086                         if (ip6rd.relay_prefixlen > 32 ||
1087                             ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64)
1088                                 goto done;
1089
1090                         ipv6_addr_prefix(&prefix, &ip6rd.prefix,
1091                                          ip6rd.prefixlen);
1092                         if (!ipv6_addr_equal(&prefix, &ip6rd.prefix))
1093                                 goto done;
1094                         if (ip6rd.relay_prefixlen)
1095                                 relay_prefix = ip6rd.relay_prefix &
1096                                                htonl(0xffffffffUL <<
1097                                                      (32 - ip6rd.relay_prefixlen));
1098                         else
1099                                 relay_prefix = 0;
1100                         if (relay_prefix != ip6rd.relay_prefix)
1101                                 goto done;
1102
1103                         t->ip6rd.prefix = prefix;
1104                         t->ip6rd.relay_prefix = relay_prefix;
1105                         t->ip6rd.prefixlen = ip6rd.prefixlen;
1106                         t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen;
1107                 } else
1108                         ipip6_tunnel_clone_6rd(dev, sitn);
1109
1110                 err = 0;
1111                 break;
1112 #endif
1113
1114         default:
1115                 err = -EINVAL;
1116         }
1117
1118 done:
1119         return err;
1120 }
1121
1122 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1123 {
1124         if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1125                 return -EINVAL;
1126         dev->mtu = new_mtu;
1127         return 0;
1128 }
1129
1130 static const struct net_device_ops ipip6_netdev_ops = {
1131         .ndo_uninit     = ipip6_tunnel_uninit,
1132         .ndo_start_xmit = ipip6_tunnel_xmit,
1133         .ndo_do_ioctl   = ipip6_tunnel_ioctl,
1134         .ndo_change_mtu = ipip6_tunnel_change_mtu,
1135         .ndo_get_stats64= ipip6_get_stats64,
1136 };
1137
1138 static void ipip6_dev_free(struct net_device *dev)
1139 {
1140         free_percpu(dev->tstats);
1141         free_netdev(dev);
1142 }
1143
1144 static void ipip6_tunnel_setup(struct net_device *dev)
1145 {
1146         dev->netdev_ops         = &ipip6_netdev_ops;
1147         dev->destructor         = ipip6_dev_free;
1148
1149         dev->type               = ARPHRD_SIT;
1150         dev->hard_header_len    = LL_MAX_HEADER + sizeof(struct iphdr);
1151         dev->mtu                = ETH_DATA_LEN - sizeof(struct iphdr);
1152         dev->flags              = IFF_NOARP;
1153         dev->priv_flags        &= ~IFF_XMIT_DST_RELEASE;
1154         dev->iflink             = 0;
1155         dev->addr_len           = 4;
1156         dev->features           |= NETIF_F_NETNS_LOCAL;
1157         dev->features           |= NETIF_F_LLTX;
1158 }
1159
1160 static int ipip6_tunnel_init(struct net_device *dev)
1161 {
1162         struct ip_tunnel *tunnel = netdev_priv(dev);
1163
1164         tunnel->dev = dev;
1165
1166         memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1167         memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1168
1169         ipip6_tunnel_bind_dev(dev);
1170         dev->tstats = alloc_percpu(struct pcpu_tstats);
1171         if (!dev->tstats)
1172                 return -ENOMEM;
1173
1174         return 0;
1175 }
1176
1177 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1178 {
1179         struct ip_tunnel *tunnel = netdev_priv(dev);
1180         struct iphdr *iph = &tunnel->parms.iph;
1181         struct net *net = dev_net(dev);
1182         struct sit_net *sitn = net_generic(net, sit_net_id);
1183
1184         tunnel->dev = dev;
1185         strcpy(tunnel->parms.name, dev->name);
1186
1187         iph->version            = 4;
1188         iph->protocol           = IPPROTO_IPV6;
1189         iph->ihl                = 5;
1190         iph->ttl                = 64;
1191
1192         dev->tstats = alloc_percpu(struct pcpu_tstats);
1193         if (!dev->tstats)
1194                 return -ENOMEM;
1195         dev_hold(dev);
1196         rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1197         return 0;
1198 }
1199
1200 static size_t ipip6_get_size(const struct net_device *dev)
1201 {
1202         return
1203                 /* IFLA_IPTUN_LINK */
1204                 nla_total_size(4) +
1205                 /* IFLA_IPTUN_LOCAL */
1206                 nla_total_size(4) +
1207                 /* IFLA_IPTUN_REMOTE */
1208                 nla_total_size(4) +
1209                 /* IFLA_IPTUN_TTL */
1210                 nla_total_size(1) +
1211                 /* IFLA_IPTUN_TOS */
1212                 nla_total_size(1) +
1213                 /* IFLA_IPTUN_PMTUDISC */
1214                 nla_total_size(1) +
1215                 /* IFLA_IPTUN_FLAGS */
1216                 nla_total_size(2) +
1217                 0;
1218 }
1219
1220 static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1221 {
1222         struct ip_tunnel *tunnel = netdev_priv(dev);
1223         struct ip_tunnel_parm *parm = &tunnel->parms;
1224
1225         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1226             nla_put_be32(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1227             nla_put_be32(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1228             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1229             nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1230             nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1231                        !!(parm->iph.frag_off & htons(IP_DF))) ||
1232             nla_put_u16(skb, IFLA_IPTUN_FLAGS, parm->i_flags))
1233                 goto nla_put_failure;
1234         return 0;
1235
1236 nla_put_failure:
1237         return -EMSGSIZE;
1238 }
1239
1240 static struct rtnl_link_ops sit_link_ops __read_mostly = {
1241         .kind           = "sit",
1242         .maxtype        = IFLA_IPTUN_MAX,
1243         .priv_size      = sizeof(struct ip_tunnel),
1244         .get_size       = ipip6_get_size,
1245         .fill_info      = ipip6_fill_info,
1246 };
1247
1248 static struct xfrm_tunnel sit_handler __read_mostly = {
1249         .handler        =       ipip6_rcv,
1250         .err_handler    =       ipip6_err,
1251         .priority       =       1,
1252 };
1253
1254 static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head)
1255 {
1256         int prio;
1257
1258         for (prio = 1; prio < 4; prio++) {
1259                 int h;
1260                 for (h = 0; h < HASH_SIZE; h++) {
1261                         struct ip_tunnel *t;
1262
1263                         t = rtnl_dereference(sitn->tunnels[prio][h]);
1264                         while (t != NULL) {
1265                                 unregister_netdevice_queue(t->dev, head);
1266                                 t = rtnl_dereference(t->next);
1267                         }
1268                 }
1269         }
1270 }
1271
1272 static int __net_init sit_init_net(struct net *net)
1273 {
1274         struct sit_net *sitn = net_generic(net, sit_net_id);
1275         struct ip_tunnel *t;
1276         int err;
1277
1278         sitn->tunnels[0] = sitn->tunnels_wc;
1279         sitn->tunnels[1] = sitn->tunnels_l;
1280         sitn->tunnels[2] = sitn->tunnels_r;
1281         sitn->tunnels[3] = sitn->tunnels_r_l;
1282
1283         sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1284                                            ipip6_tunnel_setup);
1285         if (!sitn->fb_tunnel_dev) {
1286                 err = -ENOMEM;
1287                 goto err_alloc_dev;
1288         }
1289         dev_net_set(sitn->fb_tunnel_dev, net);
1290
1291         err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1292         if (err)
1293                 goto err_dev_free;
1294
1295         ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1296
1297         if ((err = register_netdev(sitn->fb_tunnel_dev)))
1298                 goto err_reg_dev;
1299
1300         t = netdev_priv(sitn->fb_tunnel_dev);
1301
1302         strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1303         return 0;
1304
1305 err_reg_dev:
1306         dev_put(sitn->fb_tunnel_dev);
1307 err_dev_free:
1308         ipip6_dev_free(sitn->fb_tunnel_dev);
1309 err_alloc_dev:
1310         return err;
1311 }
1312
1313 static void __net_exit sit_exit_net(struct net *net)
1314 {
1315         struct sit_net *sitn = net_generic(net, sit_net_id);
1316         LIST_HEAD(list);
1317
1318         rtnl_lock();
1319         sit_destroy_tunnels(sitn, &list);
1320         unregister_netdevice_queue(sitn->fb_tunnel_dev, &list);
1321         unregister_netdevice_many(&list);
1322         rtnl_unlock();
1323 }
1324
1325 static struct pernet_operations sit_net_ops = {
1326         .init = sit_init_net,
1327         .exit = sit_exit_net,
1328         .id   = &sit_net_id,
1329         .size = sizeof(struct sit_net),
1330 };
1331
1332 static void __exit sit_cleanup(void)
1333 {
1334         rtnl_link_unregister(&sit_link_ops);
1335         xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1336
1337         unregister_pernet_device(&sit_net_ops);
1338         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1339 }
1340
1341 static int __init sit_init(void)
1342 {
1343         int err;
1344
1345         pr_info("IPv6 over IPv4 tunneling driver\n");
1346
1347         err = register_pernet_device(&sit_net_ops);
1348         if (err < 0)
1349                 return err;
1350         err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1351         if (err < 0) {
1352                 pr_info("%s: can't add protocol\n", __func__);
1353                 goto xfrm_tunnel_failed;
1354         }
1355         err = rtnl_link_register(&sit_link_ops);
1356         if (err < 0)
1357                 goto rtnl_link_failed;
1358
1359 out:
1360         return err;
1361
1362 rtnl_link_failed:
1363         xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1364 xfrm_tunnel_failed:
1365         unregister_pernet_device(&sit_net_ops);
1366         goto out;
1367 }
1368
1369 module_init(sit_init);
1370 module_exit(sit_cleanup);
1371 MODULE_LICENSE("GPL");
1372 MODULE_ALIAS_NETDEV("sit0");