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             <[email protected]>
   7  *      Alexey Kuznetsov        <[email protected]>
   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 <[email protected]>:       6to4 support
  16  * Nate Thompson <[email protected]>:             6to4 support
  17  * Fred Templin <[email protected]>:    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 bool log_ecn_error = true;
  69 module_param(log_ecn_error, bool, 0644);
  70 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
  71
  72 static int ipip6_tunnel_init(struct net_device *dev);
  73 static void ipip6_tunnel_setup(struct net_device *dev);
  74 static void ipip6_dev_free(struct net_device *dev);
  75 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
  76                       __be32 *v4dst);
  77 static struct rtnl_link_ops sit_link_ops __read_mostly;
  78
  79 static int sit_net_id __read_mostly;
  80 struct sit_net {
  81         struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE];
  82         struct ip_tunnel __rcu *tunnels_r[HASH_SIZE];
  83         struct ip_tunnel __rcu *tunnels_l[HASH_SIZE];
  84         struct ip_tunnel __rcu *tunnels_wc[1];
  85         struct ip_tunnel __rcu **tunnels[4];
  86
  87         struct net_device *fb_tunnel_dev;
  88 };
  89
  90 static struct rtnl_link_stats64 *ipip6_get_stats64(struct net_device *dev,
  91                                                    struct rtnl_link_stats64 *tot)
  92 {
  93         int i;
  94
  95         for_each_possible_cpu(i) {
  96                 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
  97                 u64 rx_packets, rx_bytes, tx_packets, tx_bytes;
  98                 unsigned int start;
  99
 100                 do {
 101                         start = u64_stats_fetch_begin_bh(&tstats->syncp);
 102                         rx_packets = tstats->rx_packets;
 103                         tx_packets = tstats->tx_packets;
 104                         rx_bytes = tstats->rx_bytes;
 105                         tx_bytes = tstats->tx_bytes;
 106                 } while (u64_stats_fetch_retry_bh(&tstats->syncp, start));
 107
 108                 tot->rx_packets += rx_packets;
 109                 tot->tx_packets += tx_packets;
 110                 tot->rx_bytes   += rx_bytes;
 111                 tot->tx_bytes   += tx_bytes;
 112         }
 113
 114         tot->rx_errors = dev->stats.rx_errors;
 115         tot->rx_frame_errors = dev->stats.rx_frame_errors;
 116         tot->tx_fifo_errors = dev->stats.tx_fifo_errors;
 117         tot->tx_carrier_errors = dev->stats.tx_carrier_errors;
 118         tot->tx_dropped = dev->stats.tx_dropped;
 119         tot->tx_aborted_errors = dev->stats.tx_aborted_errors;
 120         tot->tx_errors = dev->stats.tx_errors;
 121
 122         return tot;
 123 }
 124
 125 /*
 126  * Must be invoked with rcu_read_lock
 127  */
 128 static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net,
 129                 struct net_device *dev, __be32 remote, __be32 local)
 130 {
 131         unsigned int h0 = HASH(remote);
 132         unsigned int h1 = HASH(local);
 133         struct ip_tunnel *t;
 134         struct sit_net *sitn = net_generic(net, sit_net_id);
 135
 136         for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) {
 137                 if (local == t->parms.iph.saddr &&
 138                     remote == t->parms.iph.daddr &&
 139                     (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
 140                     (t->dev->flags & IFF_UP))
 141                         return t;
 142         }
 143         for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) {
 144                 if (remote == t->parms.iph.daddr &&
 145                     (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
 146                     (t->dev->flags & IFF_UP))
 147                         return t;
 148         }
 149         for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) {
 150                 if (local == t->parms.iph.saddr &&
 151                     (!dev || !t->parms.link || dev->iflink == t->parms.link) &&
 152                     (t->dev->flags & IFF_UP))
 153                         return t;
 154         }
 155         t = rcu_dereference(sitn->tunnels_wc[0]);
 156         if ((t != NULL) && (t->dev->flags & IFF_UP))
 157                 return t;
 158         return NULL;
 159 }
 160
 161 static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn,
 162                 struct ip_tunnel_parm *parms)
 163 {
 164         __be32 remote = parms->iph.daddr;
 165         __be32 local = parms->iph.saddr;
 166         unsigned int h = 0;
 167         int prio = 0;
 168
 169         if (remote) {
 170                 prio |= 2;
 171                 h ^= HASH(remote);
 172         }
 173         if (local) {
 174                 prio |= 1;
 175                 h ^= HASH(local);
 176         }
 177         return &sitn->tunnels[prio][h];
 178 }
 179
 180 static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn,
 181                 struct ip_tunnel *t)
 182 {
 183         return __ipip6_bucket(sitn, &t->parms);
 184 }
 185
 186 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t)
 187 {
 188         struct ip_tunnel __rcu **tp;
 189         struct ip_tunnel *iter;
 190
 191         for (tp = ipip6_bucket(sitn, t);
 192              (iter = rtnl_dereference(*tp)) != NULL;
 193              tp = &iter->next) {
 194                 if (t == iter) {
 195                         rcu_assign_pointer(*tp, t->next);
 196                         break;
 197                 }
 198         }
 199 }
 200
 201 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t)
 202 {
 203         struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t);
 204
 205         rcu_assign_pointer(t->next, rtnl_dereference(*tp));
 206         rcu_assign_pointer(*tp, t);
 207 }
 208
 209 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn)
 210 {
 211 #ifdef CONFIG_IPV6_SIT_6RD
 212         struct ip_tunnel *t = netdev_priv(dev);
 213
 214         if (t->dev == sitn->fb_tunnel_dev) {
 215                 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0);
 216                 t->ip6rd.relay_prefix = 0;
 217                 t->ip6rd.prefixlen = 16;
 218                 t->ip6rd.relay_prefixlen = 0;
 219         } else {
 220                 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev);
 221                 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd));
 222         }
 223 #endif
 224 }
 225
 226 static int ipip6_tunnel_create(struct net_device *dev)
 227 {
 228         struct ip_tunnel *t = netdev_priv(dev);
 229         struct net *net = dev_net(dev);
 230         struct sit_net *sitn = net_generic(net, sit_net_id);
 231         int err;
 232
 233         err = ipip6_tunnel_init(dev);
 234         if (err < 0)
 235                 goto out;
 236         ipip6_tunnel_clone_6rd(dev, sitn);
 237
 238         if ((__force u16)t->parms.i_flags & SIT_ISATAP)
 239                 dev->priv_flags |= IFF_ISATAP;
 240
 241         err = register_netdevice(dev);
 242         if (err < 0)
 243                 goto out;
 244
 245         strcpy(t->parms.name, dev->name);
 246         dev->rtnl_link_ops = &sit_link_ops;
 247
 248         dev_hold(dev);
 249
 250         ipip6_tunnel_link(sitn, t);
 251         return 0;
 252
 253 out:
 254         return err;
 255 }
 256
 257 static struct ip_tunnel *ipip6_tunnel_locate(struct net *net,
 258                 struct ip_tunnel_parm *parms, int create)
 259 {
 260         __be32 remote = parms->iph.daddr;
 261         __be32 local = parms->iph.saddr;
 262         struct ip_tunnel *t, *nt;
 263         struct ip_tunnel __rcu **tp;
 264         struct net_device *dev;
 265         char name[IFNAMSIZ];
 266         struct sit_net *sitn = net_generic(net, sit_net_id);
 267
 268         for (tp = __ipip6_bucket(sitn, parms);
 269             (t = rtnl_dereference(*tp)) != NULL;
 270              tp = &t->next) {
 271                 if (local == t->parms.iph.saddr &&
 272                     remote == t->parms.iph.daddr &&
 273                     parms->link == t->parms.link) {
 274                         if (create)
 275                                 return NULL;
 276                         else
 277                                 return t;
 278                 }
 279         }
 280         if (!create)
 281                 goto failed;
 282
 283         if (parms->name[0])
 284                 strlcpy(name, parms->name, IFNAMSIZ);
 285         else
 286                 strcpy(name, "sit%d");
 287
 288         dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup);
 289         if (dev == NULL)
 290                 return NULL;
 291
 292         dev_net_set(dev, net);
 293
 294         nt = netdev_priv(dev);
 295
 296         nt->parms = *parms;
 297         if (ipip6_tunnel_create(dev) < 0)
 298                 goto failed_free;
 299
 300         return nt;
 301
 302 failed_free:
 303         ipip6_dev_free(dev);
 304 failed:
 305         return NULL;
 306 }
 307
 308 #define for_each_prl_rcu(start)                 \
 309         for (prl = rcu_dereference(start);      \
 310              prl;                               \
 311              prl = rcu_dereference(prl->next))
 312
 313 static struct ip_tunnel_prl_entry *
 314 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr)
 315 {
 316         struct ip_tunnel_prl_entry *prl;
 317
 318         for_each_prl_rcu(t->prl)
 319                 if (prl->addr == addr)
 320                         break;
 321         return prl;
 322
 323 }
 324
 325 static int ipip6_tunnel_get_prl(struct ip_tunnel *t,
 326                                 struct ip_tunnel_prl __user *a)
 327 {
 328         struct ip_tunnel_prl kprl, *kp;
 329         struct ip_tunnel_prl_entry *prl;
 330         unsigned int cmax, c = 0, ca, len;
 331         int ret = 0;
 332
 333         if (copy_from_user(&kprl, a, sizeof(kprl)))
 334                 return -EFAULT;
 335         cmax = kprl.datalen / sizeof(kprl);
 336         if (cmax > 1 && kprl.addr != htonl(INADDR_ANY))
 337                 cmax = 1;
 338
 339         /* For simple GET or for root users,
 340          * we try harder to allocate.
 341          */
 342         kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ?
 343                 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) :
 344                 NULL;
 345
 346         rcu_read_lock();
 347
 348         ca = t->prl_count < cmax ? t->prl_count : cmax;
 349
 350         if (!kp) {
 351                 /* We don't try hard to allocate much memory for
 352                  * non-root users.
 353                  * For root users, retry allocating enough memory for
 354                  * the answer.
 355                  */
 356                 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC);
 357                 if (!kp) {
 358                         ret = -ENOMEM;
 359                         goto out;
 360                 }
 361         }
 362
 363         c = 0;
 364         for_each_prl_rcu(t->prl) {
 365                 if (c >= cmax)
 366                         break;
 367                 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr)
 368                         continue;
 369                 kp[c].addr = prl->addr;
 370                 kp[c].flags = prl->flags;
 371                 c++;
 372                 if (kprl.addr != htonl(INADDR_ANY))
 373                         break;
 374         }
 375 out:
 376         rcu_read_unlock();
 377
 378         len = sizeof(*kp) * c;
 379         ret = 0;
 380         if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
 381                 ret = -EFAULT;
 382
 383         kfree(kp);
 384
 385         return ret;
 386 }
 387
 388 static int
 389 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg)
 390 {
 391         struct ip_tunnel_prl_entry *p;
 392         int err = 0;
 393
 394         if (a->addr == htonl(INADDR_ANY))
 395                 return -EINVAL;
 396
 397         ASSERT_RTNL();
 398
 399         for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) {
 400                 if (p->addr == a->addr) {
 401                         if (chg) {
 402                                 p->flags = a->flags;
 403                                 goto out;
 404                         }
 405                         err = -EEXIST;
 406                         goto out;
 407                 }
 408         }
 409
 410         if (chg) {
 411                 err = -ENXIO;
 412                 goto out;
 413         }
 414
 415         p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL);
 416         if (!p) {
 417                 err = -ENOBUFS;
 418                 goto out;
 419         }
 420
 421         p->next = t->prl;
 422         p->addr = a->addr;
 423         p->flags = a->flags;
 424         t->prl_count++;
 425         rcu_assign_pointer(t->prl, p);
 426 out:
 427         return err;
 428 }
 429
 430 static void prl_list_destroy_rcu(struct rcu_head *head)
 431 {
 432         struct ip_tunnel_prl_entry *p, *n;
 433
 434         p = container_of(head, struct ip_tunnel_prl_entry, rcu_head);
 435         do {
 436                 n = rcu_dereference_protected(p->next, 1);
 437                 kfree(p);
 438                 p = n;
 439         } while (p);
 440 }
 441
 442 static int
 443 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a)
 444 {
 445         struct ip_tunnel_prl_entry *x;
 446         struct ip_tunnel_prl_entry __rcu **p;
 447         int err = 0;
 448
 449         ASSERT_RTNL();
 450
 451         if (a && a->addr != htonl(INADDR_ANY)) {
 452                 for (p = &t->prl;
 453                      (x = rtnl_dereference(*p)) != NULL;
 454                      p = &x->next) {
 455                         if (x->addr == a->addr) {
 456                                 *p = x->next;
 457                                 kfree_rcu(x, rcu_head);
 458                                 t->prl_count--;
 459                                 goto out;
 460                         }
 461                 }
 462                 err = -ENXIO;
 463         } else {
 464                 x = rtnl_dereference(t->prl);
 465                 if (x) {
 466                         t->prl_count = 0;
 467                         call_rcu(&x->rcu_head, prl_list_destroy_rcu);
 468                         t->prl = NULL;
 469                 }
 470         }
 471 out:
 472         return err;
 473 }
 474
 475 static int
 476 isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t)
 477 {
 478         struct ip_tunnel_prl_entry *p;
 479         int ok = 1;
 480
 481         rcu_read_lock();
 482         p = __ipip6_tunnel_locate_prl(t, iph->saddr);
 483         if (p) {
 484                 if (p->flags & PRL_DEFAULT)
 485                         skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT;
 486                 else
 487                         skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT;
 488         } else {
 489                 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr;
 490
 491                 if (ipv6_addr_is_isatap(addr6) &&
 492                     (addr6->s6_addr32[3] == iph->saddr) &&
 493                     ipv6_chk_prefix(addr6, t->dev))
 494                         skb->ndisc_nodetype = NDISC_NODETYPE_HOST;
 495                 else
 496                         ok = 0;
 497         }
 498         rcu_read_unlock();
 499         return ok;
 500 }
 501
 502 static void ipip6_tunnel_uninit(struct net_device *dev)
 503 {
 504         struct net *net = dev_net(dev);
 505         struct sit_net *sitn = net_generic(net, sit_net_id);
 506
 507         if (dev == sitn->fb_tunnel_dev) {
 508                 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL);
 509         } else {
 510                 ipip6_tunnel_unlink(sitn, netdev_priv(dev));
 511                 ipip6_tunnel_del_prl(netdev_priv(dev), NULL);
 512         }
 513         dev_put(dev);
 514 }
 515
 516
 517 static int ipip6_err(struct sk_buff *skb, u32 info)
 518 {
 519
 520 /* All the routers (except for Linux) return only
 521    8 bytes of packet payload. It means, that precise relaying of
 522    ICMP in the real Internet is absolutely infeasible.
 523  */
 524         const struct iphdr *iph = (const struct iphdr *)skb->data;
 525         const int type = icmp_hdr(skb)->type;
 526         const int code = icmp_hdr(skb)->code;
 527         struct ip_tunnel *t;
 528         int err;
 529
 530         switch (type) {
 531         default:
 532         case ICMP_PARAMETERPROB:
 533                 return 0;
 534
 535         case ICMP_DEST_UNREACH:
 536                 switch (code) {
 537                 case ICMP_SR_FAILED:
 538                 case ICMP_PORT_UNREACH:
 539                         /* Impossible event. */
 540                         return 0;
 541                 default:
 542                         /* All others are translated to HOST_UNREACH.
 543                            rfc2003 contains "deep thoughts" about NET_UNREACH,
 544                            I believe they are just ether pollution. --ANK
 545                          */
 546                         break;
 547                 }
 548                 break;
 549         case ICMP_TIME_EXCEEDED:
 550                 if (code != ICMP_EXC_TTL)
 551                         return 0;
 552                 break;
 553         case ICMP_REDIRECT:
 554                 break;
 555         }
 556
 557         err = -ENOENT;
 558
 559         t = ipip6_tunnel_lookup(dev_net(skb->dev),
 560                                 skb->dev,
 561                                 iph->daddr,
 562                                 iph->saddr);
 563         if (t == NULL)
 564                 goto out;
 565
 566         if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
 567                 ipv4_update_pmtu(skb, dev_net(skb->dev), info,
 568                                  t->dev->ifindex, 0, IPPROTO_IPV6, 0);
 569                 err = 0;
 570                 goto out;
 571         }
 572         if (type == ICMP_REDIRECT) {
 573                 ipv4_redirect(skb, dev_net(skb->dev), t->dev->ifindex, 0,
 574                               IPPROTO_IPV6, 0);
 575                 err = 0;
 576                 goto out;
 577         }
 578
 579         if (t->parms.iph.daddr == 0)
 580                 goto out;
 581
 582         err = 0;
 583         if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
 584                 goto out;
 585
 586         if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
 587                 t->err_count++;
 588         else
 589                 t->err_count = 1;
 590         t->err_time = jiffies;
 591 out:
 592         return err;
 593 }
 594
 595 static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr,
 596                                   const struct in6_addr *v6addr)
 597 {
 598         __be32 v4embed = 0;
 599         if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed)
 600                 return true;
 601         return false;
 602 }
 603
 604 static int ipip6_rcv(struct sk_buff *skb)
 605 {
 606         const struct iphdr *iph = ip_hdr(skb);
 607         struct ip_tunnel *tunnel;
 608         int err;
 609
 610         tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev,
 611                                      iph->saddr, iph->daddr);
 612         if (tunnel != NULL) {
 613                 struct pcpu_tstats *tstats;
 614
 615                 secpath_reset(skb);
 616                 skb->mac_header = skb->network_header;
 617                 skb_reset_network_header(skb);
 618                 IPCB(skb)->flags = 0;
 619                 skb->protocol = htons(ETH_P_IPV6);
 620                 skb->pkt_type = PACKET_HOST;
 621
 622                 if (tunnel->dev->priv_flags & IFF_ISATAP) {
 623                         if (!isatap_chksrc(skb, iph, tunnel)) {
 624                                 tunnel->dev->stats.rx_errors++;
 625                                 goto out;
 626                         }
 627                 } else {
 628                         if (is_spoofed_6rd(tunnel, iph->saddr,
 629                                            &ipv6_hdr(skb)->saddr) ||
 630                             is_spoofed_6rd(tunnel, iph->daddr,
 631                                            &ipv6_hdr(skb)->daddr)) {
 632                                 tunnel->dev->stats.rx_errors++;
 633                                 goto out;
 634                         }
 635                 }
 636
 637                 __skb_tunnel_rx(skb, tunnel->dev);
 638
 639                 err = IP_ECN_decapsulate(iph, skb);
 640                 if (unlikely(err)) {
 641                         if (log_ecn_error)
 642                                 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n",
 643                                                      &iph->saddr, iph->tos);
 644                         if (err > 1) {
 645                                 ++tunnel->dev->stats.rx_frame_errors;
 646                                 ++tunnel->dev->stats.rx_errors;
 647                                 goto out;
 648                         }
 649                 }
 650
 651                 tstats = this_cpu_ptr(tunnel->dev->tstats);
 652                 tstats->rx_packets++;
 653                 tstats->rx_bytes += skb->len;
 654
 655                 netif_rx(skb);
 656
 657                 return 0;
 658         }
 659
 660         /* no tunnel matched,  let upstream know, ipsec may handle it */
 661         return 1;
 662 out:
 663         kfree_skb(skb);
 664         return 0;
 665 }
 666
 667 /*
 668  * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function
 669  * stores the embedded IPv4 address in v4dst and returns true.
 670  */
 671 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst,
 672                       __be32 *v4dst)
 673 {
 674 #ifdef CONFIG_IPV6_SIT_6RD
 675         if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix,
 676                               tunnel->ip6rd.prefixlen)) {
 677                 unsigned int pbw0, pbi0;
 678                 int pbi1;
 679                 u32 d;
 680
 681                 pbw0 = tunnel->ip6rd.prefixlen >> 5;
 682                 pbi0 = tunnel->ip6rd.prefixlen & 0x1f;
 683
 684                 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >>
 685                     tunnel->ip6rd.relay_prefixlen;
 686
 687                 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen;
 688                 if (pbi1 > 0)
 689                         d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >>
 690                              (32 - pbi1);
 691
 692                 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d);
 693                 return true;
 694         }
 695 #else
 696         if (v6dst->s6_addr16[0] == htons(0x2002)) {
 697                 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */
 698                 memcpy(v4dst, &v6dst->s6_addr16[1], 4);
 699                 return true;
 700         }
 701 #endif
 702         return false;
 703 }
 704
 705 static inline __be32 try_6rd(struct ip_tunnel *tunnel,
 706                              const struct in6_addr *v6dst)
 707 {
 708         __be32 dst = 0;
 709         check_6rd(tunnel, v6dst, &dst);
 710         return dst;
 711 }
 712
 713 /*
 714  *      This function assumes it is being called from dev_queue_xmit()
 715  *      and that skb is filled properly by that function.
 716  */
 717
 718 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
 719                                      struct net_device *dev)
 720 {
 721         struct ip_tunnel *tunnel = netdev_priv(dev);
 722         const struct iphdr  *tiph = &tunnel->parms.iph;
 723         const struct ipv6hdr *iph6 = ipv6_hdr(skb);
 724         u8     tos = tunnel->parms.iph.tos;
 725         __be16 df = tiph->frag_off;
 726         struct rtable *rt;                      /* Route to the other host */
 727         struct net_device *tdev;                /* Device to other host */
 728         struct iphdr  *iph;                     /* Our new IP header */
 729         unsigned int max_headroom;              /* The extra header space needed */
 730         __be32 dst = tiph->daddr;
 731         struct flowi4 fl4;
 732         int    mtu;
 733         const struct in6_addr *addr6;
 734         int addr_type;
 735
 736         if (skb->protocol != htons(ETH_P_IPV6))
 737                 goto tx_error;
 738
 739         if (tos == 1)
 740                 tos = ipv6_get_dsfield(iph6);
 741
 742         /* ISATAP (RFC4214) - must come before 6to4 */
 743         if (dev->priv_flags & IFF_ISATAP) {
 744                 struct neighbour *neigh = NULL;
 745                 bool do_tx_error = false;
 746
 747                 if (skb_dst(skb))
 748                         neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 749
 750                 if (neigh == NULL) {
 751                         net_dbg_ratelimited("sit: nexthop == NULL\n");
 752                         goto tx_error;
 753                 }
 754
 755                 addr6 = (const struct in6_addr *)&neigh->primary_key;
 756                 addr_type = ipv6_addr_type(addr6);
 757
 758                 if ((addr_type & IPV6_ADDR_UNICAST) &&
 759                      ipv6_addr_is_isatap(addr6))
 760                         dst = addr6->s6_addr32[3];
 761                 else
 762                         do_tx_error = true;
 763
 764                 neigh_release(neigh);
 765                 if (do_tx_error)
 766                         goto tx_error;
 767         }
 768
 769         if (!dst)
 770                 dst = try_6rd(tunnel, &iph6->daddr);
 771
 772         if (!dst) {
 773                 struct neighbour *neigh = NULL;
 774                 bool do_tx_error = false;
 775
 776                 if (skb_dst(skb))
 777                         neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr);
 778
 779                 if (neigh == NULL) {
 780                         net_dbg_ratelimited("sit: nexthop == NULL\n");
 781                         goto tx_error;
 782                 }
 783
 784                 addr6 = (const struct in6_addr *)&neigh->primary_key;
 785                 addr_type = ipv6_addr_type(addr6);
 786
 787                 if (addr_type == IPV6_ADDR_ANY) {
 788                         addr6 = &ipv6_hdr(skb)->daddr;
 789                         addr_type = ipv6_addr_type(addr6);
 790                 }
 791
 792                 if ((addr_type & IPV6_ADDR_COMPATv4) != 0)
 793                         dst = addr6->s6_addr32[3];
 794                 else
 795                         do_tx_error = true;
 796
 797                 neigh_release(neigh);
 798                 if (do_tx_error)
 799                         goto tx_error;
 800         }
 801
 802         rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
 803                                    dst, tiph->saddr,
 804                                    0, 0,
 805                                    IPPROTO_IPV6, RT_TOS(tos),
 806                                    tunnel->parms.link);
 807         if (IS_ERR(rt)) {
 808                 dev->stats.tx_carrier_errors++;
 809                 goto tx_error_icmp;
 810         }
 811         if (rt->rt_type != RTN_UNICAST) {
 812                 ip_rt_put(rt);
 813                 dev->stats.tx_carrier_errors++;
 814                 goto tx_error_icmp;
 815         }
 816         tdev = rt->dst.dev;
 817
 818         if (tdev == dev) {
 819                 ip_rt_put(rt);
 820                 dev->stats.collisions++;
 821                 goto tx_error;
 822         }
 823
 824         if (df) {
 825                 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr);
 826
 827                 if (mtu < 68) {
 828                         dev->stats.collisions++;
 829                         ip_rt_put(rt);
 830                         goto tx_error;
 831                 }
 832
 833                 if (mtu < IPV6_MIN_MTU) {
 834                         mtu = IPV6_MIN_MTU;
 835                         df = 0;
 836                 }
 837
 838                 if (tunnel->parms.iph.daddr && skb_dst(skb))
 839                         skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 840
 841                 if (skb->len > mtu) {
 842                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 843                         ip_rt_put(rt);
 844                         goto tx_error;
 845                 }
 846         }
 847
 848         if (tunnel->err_count > 0) {
 849                 if (time_before(jiffies,
 850                                 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
 851                         tunnel->err_count--;
 852                         dst_link_failure(skb);
 853                 } else
 854                         tunnel->err_count = 0;
 855         }
 856
 857         /*
 858          * Okay, now see if we can stuff it in the buffer as-is.
 859          */
 860         max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr);
 861
 862         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 863             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 864                 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
 865                 if (!new_skb) {
 866                         ip_rt_put(rt);
 867                         dev->stats.tx_dropped++;
 868                         dev_kfree_skb(skb);
 869                         return NETDEV_TX_OK;
 870                 }
 871                 if (skb->sk)
 872                         skb_set_owner_w(new_skb, skb->sk);
 873                 dev_kfree_skb(skb);
 874                 skb = new_skb;
 875                 iph6 = ipv6_hdr(skb);
 876         }
 877
 878         skb->transport_header = skb->network_header;
 879         skb_push(skb, sizeof(struct iphdr));
 880         skb_reset_network_header(skb);
 881         memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
 882         IPCB(skb)->flags = 0;
 883         skb_dst_drop(skb);
 884         skb_dst_set(skb, &rt->dst);
 885
 886         /*
 887          *      Push down and install the IPIP header.
 888          */
 889
 890         iph                     =       ip_hdr(skb);
 891         iph->version            =       4;
 892         iph->ihl                =       sizeof(struct iphdr)>>2;
 893         iph->frag_off           =       df;
 894         iph->protocol           =       IPPROTO_IPV6;
 895         iph->tos                =       INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6));
 896         iph->daddr              =       fl4.daddr;
 897         iph->saddr              =       fl4.saddr;
 898
 899         if ((iph->ttl = tiph->ttl) == 0)
 900                 iph->ttl        =       iph6->hop_limit;
 901
 902         iptunnel_xmit(skb, dev);
 903         return NETDEV_TX_OK;
 904
 905 tx_error_icmp:
 906         dst_link_failure(skb);
 907 tx_error:
 908         dev->stats.tx_errors++;
 909         dev_kfree_skb(skb);
 910         return NETDEV_TX_OK;
 911 }
 912
 913 static void ipip6_tunnel_bind_dev(struct net_device *dev)
 914 {
 915         struct net_device *tdev = NULL;
 916         struct ip_tunnel *tunnel;
 917         const struct iphdr *iph;
 918         struct flowi4 fl4;
 919
 920         tunnel = netdev_priv(dev);
 921         iph = &tunnel->parms.iph;
 922
 923         if (iph->daddr) {
 924                 struct rtable *rt = ip_route_output_ports(dev_net(dev), &fl4, NULL,
 925                                                           iph->daddr, iph->saddr,
 926                                                           0, 0,
 927                                                           IPPROTO_IPV6,
 928                                                           RT_TOS(iph->tos),
 929                                                           tunnel->parms.link);
 930
 931                 if (!IS_ERR(rt)) {
 932                         tdev = rt->dst.dev;
 933                         ip_rt_put(rt);
 934                 }
 935                 dev->flags |= IFF_POINTOPOINT;
 936         }
 937
 938         if (!tdev && tunnel->parms.link)
 939                 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
 940
 941         if (tdev) {
 942                 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
 943                 dev->mtu = tdev->mtu - sizeof(struct iphdr);
 944                 if (dev->mtu < IPV6_MIN_MTU)
 945                         dev->mtu = IPV6_MIN_MTU;
 946         }
 947         dev->iflink = tunnel->parms.link;
 948 }
 949
 950 static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p)
 951 {
 952         struct net *net = dev_net(t->dev);
 953         struct sit_net *sitn = net_generic(net, sit_net_id);
 954
 955         ipip6_tunnel_unlink(sitn, t);
 956         synchronize_net();
 957         t->parms.iph.saddr = p->iph.saddr;
 958         t->parms.iph.daddr = p->iph.daddr;
 959         memcpy(t->dev->dev_addr, &p->iph.saddr, 4);
 960         memcpy(t->dev->broadcast, &p->iph.daddr, 4);
 961         ipip6_tunnel_link(sitn, t);
 962         t->parms.iph.ttl = p->iph.ttl;
 963         t->parms.iph.tos = p->iph.tos;
 964         if (t->parms.link != p->link) {
 965                 t->parms.link = p->link;
 966                 ipip6_tunnel_bind_dev(t->dev);
 967         }
 968         netdev_state_change(t->dev);
 969 }
 970
 971 #ifdef CONFIG_IPV6_SIT_6RD
 972 static int ipip6_tunnel_update_6rd(struct ip_tunnel *t,
 973                                    struct ip_tunnel_6rd *ip6rd)
 974 {
 975         struct in6_addr prefix;
 976         __be32 relay_prefix;
 977
 978         if (ip6rd->relay_prefixlen > 32 ||
 979             ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64)
 980                 return -EINVAL;
 981
 982         ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen);
 983         if (!ipv6_addr_equal(&prefix, &ip6rd->prefix))
 984                 return -EINVAL;
 985         if (ip6rd->relay_prefixlen)
 986                 relay_prefix = ip6rd->relay_prefix &
 987                                htonl(0xffffffffUL <<
 988                                      (32 - ip6rd->relay_prefixlen));
 989         else
 990                 relay_prefix = 0;
 991         if (relay_prefix != ip6rd->relay_prefix)
 992                 return -EINVAL;
 993
 994         t->ip6rd.prefix = prefix;
 995         t->ip6rd.relay_prefix = relay_prefix;
 996         t->ip6rd.prefixlen = ip6rd->prefixlen;
 997         t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen;
 998         netdev_state_change(t->dev);
 999         return 0;
1000 }
1001 #endif
1002
1003 static int
1004 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
1005 {
1006         int err = 0;
1007         struct ip_tunnel_parm p;
1008         struct ip_tunnel_prl prl;
1009         struct ip_tunnel *t;
1010         struct net *net = dev_net(dev);
1011         struct sit_net *sitn = net_generic(net, sit_net_id);
1012 #ifdef CONFIG_IPV6_SIT_6RD
1013         struct ip_tunnel_6rd ip6rd;
1014 #endif
1015
1016         switch (cmd) {
1017         case SIOCGETTUNNEL:
1018 #ifdef CONFIG_IPV6_SIT_6RD
1019         case SIOCGET6RD:
1020 #endif
1021                 t = NULL;
1022                 if (dev == sitn->fb_tunnel_dev) {
1023                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
1024                                 err = -EFAULT;
1025                                 break;
1026                         }
1027                         t = ipip6_tunnel_locate(net, &p, 0);
1028                 }
1029                 if (t == NULL)
1030                         t = netdev_priv(dev);
1031
1032                 err = -EFAULT;
1033                 if (cmd == SIOCGETTUNNEL) {
1034                         memcpy(&p, &t->parms, sizeof(p));
1035                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p,
1036                                          sizeof(p)))
1037                                 goto done;
1038 #ifdef CONFIG_IPV6_SIT_6RD
1039                 } else {
1040                         ip6rd.prefix = t->ip6rd.prefix;
1041                         ip6rd.relay_prefix = t->ip6rd.relay_prefix;
1042                         ip6rd.prefixlen = t->ip6rd.prefixlen;
1043                         ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen;
1044                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd,
1045                                          sizeof(ip6rd)))
1046                                 goto done;
1047 #endif
1048                 }
1049                 err = 0;
1050                 break;
1051
1052         case SIOCADDTUNNEL:
1053         case SIOCCHGTUNNEL:
1054                 err = -EPERM;
1055                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1056                         goto done;
1057
1058                 err = -EFAULT;
1059                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1060                         goto done;
1061
1062                 err = -EINVAL;
1063                 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 ||
1064                     p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
1065                         goto done;
1066                 if (p.iph.ttl)
1067                         p.iph.frag_off |= htons(IP_DF);
1068
1069                 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
1070
1071                 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
1072                         if (t != NULL) {
1073                                 if (t->dev != dev) {
1074                                         err = -EEXIST;
1075                                         break;
1076                                 }
1077                         } else {
1078                                 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
1079                                     (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
1080                                         err = -EINVAL;
1081                                         break;
1082                                 }
1083                                 t = netdev_priv(dev);
1084                         }
1085
1086                         ipip6_tunnel_update(t, &p);
1087                 }
1088
1089                 if (t) {
1090                         err = 0;
1091                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
1092                                 err = -EFAULT;
1093                 } else
1094                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1095                 break;
1096
1097         case SIOCDELTUNNEL:
1098                 err = -EPERM;
1099                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1100                         goto done;
1101
1102                 if (dev == sitn->fb_tunnel_dev) {
1103                         err = -EFAULT;
1104                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
1105                                 goto done;
1106                         err = -ENOENT;
1107                         if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL)
1108                                 goto done;
1109                         err = -EPERM;
1110                         if (t == netdev_priv(sitn->fb_tunnel_dev))
1111                                 goto done;
1112                         dev = t->dev;
1113                 }
1114                 unregister_netdevice(dev);
1115                 err = 0;
1116                 break;
1117
1118         case SIOCGETPRL:
1119                 err = -EINVAL;
1120                 if (dev == sitn->fb_tunnel_dev)
1121                         goto done;
1122                 err = -ENOENT;
1123                 if (!(t = netdev_priv(dev)))
1124                         goto done;
1125                 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data);
1126                 break;
1127
1128         case SIOCADDPRL:
1129         case SIOCDELPRL:
1130         case SIOCCHGPRL:
1131                 err = -EPERM;
1132                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1133                         goto done;
1134                 err = -EINVAL;
1135                 if (dev == sitn->fb_tunnel_dev)
1136                         goto done;
1137                 err = -EFAULT;
1138                 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl)))
1139                         goto done;
1140                 err = -ENOENT;
1141                 if (!(t = netdev_priv(dev)))
1142                         goto done;
1143
1144                 switch (cmd) {
1145                 case SIOCDELPRL:
1146                         err = ipip6_tunnel_del_prl(t, &prl);
1147                         break;
1148                 case SIOCADDPRL:
1149                 case SIOCCHGPRL:
1150                         err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL);
1151                         break;
1152                 }
1153                 netdev_state_change(dev);
1154                 break;
1155
1156 #ifdef CONFIG_IPV6_SIT_6RD
1157         case SIOCADD6RD:
1158         case SIOCCHG6RD:
1159         case SIOCDEL6RD:
1160                 err = -EPERM;
1161                 if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
1162                         goto done;
1163
1164                 err = -EFAULT;
1165                 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data,
1166                                    sizeof(ip6rd)))
1167                         goto done;
1168
1169                 t = netdev_priv(dev);
1170
1171                 if (cmd != SIOCDEL6RD) {
1172                         err = ipip6_tunnel_update_6rd(t, &ip6rd);
1173                         if (err < 0)
1174                                 goto done;
1175                 } else
1176                         ipip6_tunnel_clone_6rd(dev, sitn);
1177
1178                 err = 0;
1179                 break;
1180 #endif
1181
1182         default:
1183                 err = -EINVAL;
1184         }
1185
1186 done:
1187         return err;
1188 }
1189
1190 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu)
1191 {
1192         if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr))
1193                 return -EINVAL;
1194         dev->mtu = new_mtu;
1195         return 0;
1196 }
1197
1198 static const struct net_device_ops ipip6_netdev_ops = {
1199         .ndo_uninit     = ipip6_tunnel_uninit,
1200         .ndo_start_xmit = ipip6_tunnel_xmit,
1201         .ndo_do_ioctl   = ipip6_tunnel_ioctl,
1202         .ndo_change_mtu = ipip6_tunnel_change_mtu,
1203         .ndo_get_stats64= ipip6_get_stats64,
1204 };
1205
1206 static void ipip6_dev_free(struct net_device *dev)
1207 {
1208         free_percpu(dev->tstats);
1209         free_netdev(dev);
1210 }
1211
1212 static void ipip6_tunnel_setup(struct net_device *dev)
1213 {
1214         dev->netdev_ops         = &ipip6_netdev_ops;
1215         dev->destructor         = ipip6_dev_free;
1216
1217         dev->type               = ARPHRD_SIT;
1218         dev->hard_header_len    = LL_MAX_HEADER + sizeof(struct iphdr);
1219         dev->mtu                = ETH_DATA_LEN - sizeof(struct iphdr);
1220         dev->flags              = IFF_NOARP;
1221         dev->priv_flags        &= ~IFF_XMIT_DST_RELEASE;
1222         dev->iflink             = 0;
1223         dev->addr_len           = 4;
1224         dev->features           |= NETIF_F_NETNS_LOCAL;
1225         dev->features           |= NETIF_F_LLTX;
1226 }
1227
1228 static int ipip6_tunnel_init(struct net_device *dev)
1229 {
1230         struct ip_tunnel *tunnel = netdev_priv(dev);
1231
1232         tunnel->dev = dev;
1233
1234         memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
1235         memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
1236
1237         ipip6_tunnel_bind_dev(dev);
1238         dev->tstats = alloc_percpu(struct pcpu_tstats);
1239         if (!dev->tstats)
1240                 return -ENOMEM;
1241
1242         return 0;
1243 }
1244
1245 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev)
1246 {
1247         struct ip_tunnel *tunnel = netdev_priv(dev);
1248         struct iphdr *iph = &tunnel->parms.iph;
1249         struct net *net = dev_net(dev);
1250         struct sit_net *sitn = net_generic(net, sit_net_id);
1251
1252         tunnel->dev = dev;
1253         strcpy(tunnel->parms.name, dev->name);
1254
1255         iph->version            = 4;
1256         iph->protocol           = IPPROTO_IPV6;
1257         iph->ihl                = 5;
1258         iph->ttl                = 64;
1259
1260         dev->tstats = alloc_percpu(struct pcpu_tstats);
1261         if (!dev->tstats)
1262                 return -ENOMEM;
1263         dev_hold(dev);
1264         rcu_assign_pointer(sitn->tunnels_wc[0], tunnel);
1265         return 0;
1266 }
1267
1268 static void ipip6_netlink_parms(struct nlattr *data[],
1269                                 struct ip_tunnel_parm *parms)
1270 {
1271         memset(parms, 0, sizeof(*parms));
1272
1273         parms->iph.version = 4;
1274         parms->iph.protocol = IPPROTO_IPV6;
1275         parms->iph.ihl = 5;
1276         parms->iph.ttl = 64;
1277
1278         if (!data)
1279                 return;
1280
1281         if (data[IFLA_IPTUN_LINK])
1282                 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
1283
1284         if (data[IFLA_IPTUN_LOCAL])
1285                 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
1286
1287         if (data[IFLA_IPTUN_REMOTE])
1288                 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
1289
1290         if (data[IFLA_IPTUN_TTL]) {
1291                 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
1292                 if (parms->iph.ttl)
1293                         parms->iph.frag_off = htons(IP_DF);
1294         }
1295
1296         if (data[IFLA_IPTUN_TOS])
1297                 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
1298
1299         if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
1300                 parms->iph.frag_off = htons(IP_DF);
1301
1302         if (data[IFLA_IPTUN_FLAGS])
1303                 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
1304 }
1305
1306 #ifdef CONFIG_IPV6_SIT_6RD
1307 /* This function returns true when 6RD attributes are present in the nl msg */
1308 static bool ipip6_netlink_6rd_parms(struct nlattr *data[],
1309                                     struct ip_tunnel_6rd *ip6rd)
1310 {
1311         bool ret = false;
1312         memset(ip6rd, 0, sizeof(*ip6rd));
1313
1314         if (!data)
1315                 return ret;
1316
1317         if (data[IFLA_IPTUN_6RD_PREFIX]) {
1318                 ret = true;
1319                 nla_memcpy(&ip6rd->prefix, data[IFLA_IPTUN_6RD_PREFIX],
1320                            sizeof(struct in6_addr));
1321         }
1322
1323         if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) {
1324                 ret = true;
1325                 ip6rd->relay_prefix =
1326                         nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]);
1327         }
1328
1329         if (data[IFLA_IPTUN_6RD_PREFIXLEN]) {
1330                 ret = true;
1331                 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]);
1332         }
1333
1334         if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) {
1335                 ret = true;
1336                 ip6rd->relay_prefixlen =
1337                         nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]);
1338         }
1339
1340         return ret;
1341 }
1342 #endif
1343
1344 static int ipip6_newlink(struct net *src_net, struct net_device *dev,
1345                          struct nlattr *tb[], struct nlattr *data[])
1346 {
1347         struct net *net = dev_net(dev);
1348         struct ip_tunnel *nt;
1349 #ifdef CONFIG_IPV6_SIT_6RD
1350         struct ip_tunnel_6rd ip6rd;
1351 #endif
1352         int err;
1353
1354         nt = netdev_priv(dev);
1355         ipip6_netlink_parms(data, &nt->parms);
1356
1357         if (ipip6_tunnel_locate(net, &nt->parms, 0))
1358                 return -EEXIST;
1359
1360         err = ipip6_tunnel_create(dev);
1361         if (err < 0)
1362                 return err;
1363
1364 #ifdef CONFIG_IPV6_SIT_6RD
1365         if (ipip6_netlink_6rd_parms(data, &ip6rd))
1366                 err = ipip6_tunnel_update_6rd(nt, &ip6rd);
1367 #endif
1368
1369         return err;
1370 }
1371
1372 static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[],
1373                           struct nlattr *data[])
1374 {
1375         struct ip_tunnel *t;
1376         struct ip_tunnel_parm p;
1377         struct net *net = dev_net(dev);
1378         struct sit_net *sitn = net_generic(net, sit_net_id);
1379 #ifdef CONFIG_IPV6_SIT_6RD
1380         struct ip_tunnel_6rd ip6rd;
1381 #endif
1382
1383         if (dev == sitn->fb_tunnel_dev)
1384                 return -EINVAL;
1385
1386         ipip6_netlink_parms(data, &p);
1387
1388         if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) ||
1389             (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr))
1390                 return -EINVAL;
1391
1392         t = ipip6_tunnel_locate(net, &p, 0);
1393
1394         if (t) {
1395                 if (t->dev != dev)
1396                         return -EEXIST;
1397         } else
1398                 t = netdev_priv(dev);
1399
1400         ipip6_tunnel_update(t, &p);
1401
1402 #ifdef CONFIG_IPV6_SIT_6RD
1403         if (ipip6_netlink_6rd_parms(data, &ip6rd))
1404                 return ipip6_tunnel_update_6rd(t, &ip6rd);
1405 #endif
1406
1407         return 0;
1408 }
1409
1410 static size_t ipip6_get_size(const struct net_device *dev)
1411 {
1412         return
1413                 /* IFLA_IPTUN_LINK */
1414                 nla_total_size(4) +
1415                 /* IFLA_IPTUN_LOCAL */
1416                 nla_total_size(4) +
1417                 /* IFLA_IPTUN_REMOTE */
1418                 nla_total_size(4) +
1419                 /* IFLA_IPTUN_TTL */
1420                 nla_total_size(1) +
1421                 /* IFLA_IPTUN_TOS */
1422                 nla_total_size(1) +
1423                 /* IFLA_IPTUN_PMTUDISC */
1424                 nla_total_size(1) +
1425                 /* IFLA_IPTUN_FLAGS */
1426                 nla_total_size(2) +
1427 #ifdef CONFIG_IPV6_SIT_6RD
1428                 /* IFLA_IPTUN_6RD_PREFIX */
1429                 nla_total_size(sizeof(struct in6_addr)) +
1430                 /* IFLA_IPTUN_6RD_RELAY_PREFIX */
1431                 nla_total_size(4) +
1432                 /* IFLA_IPTUN_6RD_PREFIXLEN */
1433                 nla_total_size(2) +
1434                 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */
1435                 nla_total_size(2) +
1436 #endif
1437                 0;
1438 }
1439
1440 static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev)
1441 {
1442         struct ip_tunnel *tunnel = netdev_priv(dev);
1443         struct ip_tunnel_parm *parm = &tunnel->parms;
1444
1445         if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) ||
1446             nla_put_be32(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) ||
1447             nla_put_be32(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) ||
1448             nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) ||
1449             nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) ||
1450             nla_put_u8(skb, IFLA_IPTUN_PMTUDISC,
1451                        !!(parm->iph.frag_off & htons(IP_DF))) ||
1452             nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags))
1453                 goto nla_put_failure;
1454
1455 #ifdef CONFIG_IPV6_SIT_6RD
1456         if (nla_put(skb, IFLA_IPTUN_6RD_PREFIX, sizeof(struct in6_addr),
1457                     &tunnel->ip6rd.prefix) ||
1458             nla_put_be32(skb, IFLA_IPTUN_6RD_RELAY_PREFIX,
1459                          tunnel->ip6rd.relay_prefix) ||
1460             nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN,
1461                         tunnel->ip6rd.prefixlen) ||
1462             nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN,
1463                         tunnel->ip6rd.relay_prefixlen))
1464                 goto nla_put_failure;
1465 #endif
1466
1467         return 0;
1468
1469 nla_put_failure:
1470         return -EMSGSIZE;
1471 }
1472
1473 static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = {
1474         [IFLA_IPTUN_LINK]               = { .type = NLA_U32 },
1475         [IFLA_IPTUN_LOCAL]              = { .type = NLA_U32 },
1476         [IFLA_IPTUN_REMOTE]             = { .type = NLA_U32 },
1477         [IFLA_IPTUN_TTL]                = { .type = NLA_U8 },
1478         [IFLA_IPTUN_TOS]                = { .type = NLA_U8 },
1479         [IFLA_IPTUN_PMTUDISC]           = { .type = NLA_U8 },
1480         [IFLA_IPTUN_FLAGS]              = { .type = NLA_U16 },
1481 #ifdef CONFIG_IPV6_SIT_6RD
1482         [IFLA_IPTUN_6RD_PREFIX]         = { .len = sizeof(struct in6_addr) },
1483         [IFLA_IPTUN_6RD_RELAY_PREFIX]   = { .type = NLA_U32 },
1484         [IFLA_IPTUN_6RD_PREFIXLEN]      = { .type = NLA_U16 },
1485         [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 },
1486 #endif
1487 };
1488
1489 static struct rtnl_link_ops sit_link_ops __read_mostly = {
1490         .kind           = "sit",
1491         .maxtype        = IFLA_IPTUN_MAX,
1492         .policy         = ipip6_policy,
1493         .priv_size      = sizeof(struct ip_tunnel),
1494         .setup          = ipip6_tunnel_setup,
1495         .newlink        = ipip6_newlink,
1496         .changelink     = ipip6_changelink,
1497         .get_size       = ipip6_get_size,
1498         .fill_info      = ipip6_fill_info,
1499 };
1500
1501 static struct xfrm_tunnel sit_handler __read_mostly = {
1502         .handler        =       ipip6_rcv,
1503         .err_handler    =       ipip6_err,
1504         .priority       =       1,
1505 };
1506
1507 static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head)
1508 {
1509         int prio;
1510
1511         for (prio = 1; prio < 4; prio++) {
1512                 int h;
1513                 for (h = 0; h < HASH_SIZE; h++) {
1514                         struct ip_tunnel *t;
1515
1516                         t = rtnl_dereference(sitn->tunnels[prio][h]);
1517                         while (t != NULL) {
1518                                 unregister_netdevice_queue(t->dev, head);
1519                                 t = rtnl_dereference(t->next);
1520                         }
1521                 }
1522         }
1523 }
1524
1525 static int __net_init sit_init_net(struct net *net)
1526 {
1527         struct sit_net *sitn = net_generic(net, sit_net_id);
1528         struct ip_tunnel *t;
1529         int err;
1530
1531         sitn->tunnels[0] = sitn->tunnels_wc;
1532         sitn->tunnels[1] = sitn->tunnels_l;
1533         sitn->tunnels[2] = sitn->tunnels_r;
1534         sitn->tunnels[3] = sitn->tunnels_r_l;
1535
1536         sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0",
1537                                            ipip6_tunnel_setup);
1538         if (!sitn->fb_tunnel_dev) {
1539                 err = -ENOMEM;
1540                 goto err_alloc_dev;
1541         }
1542         dev_net_set(sitn->fb_tunnel_dev, net);
1543
1544         err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev);
1545         if (err)
1546                 goto err_dev_free;
1547
1548         ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn);
1549
1550         if ((err = register_netdev(sitn->fb_tunnel_dev)))
1551                 goto err_reg_dev;
1552
1553         t = netdev_priv(sitn->fb_tunnel_dev);
1554
1555         strcpy(t->parms.name, sitn->fb_tunnel_dev->name);
1556         return 0;
1557
1558 err_reg_dev:
1559         dev_put(sitn->fb_tunnel_dev);
1560 err_dev_free:
1561         ipip6_dev_free(sitn->fb_tunnel_dev);
1562 err_alloc_dev:
1563         return err;
1564 }
1565
1566 static void __net_exit sit_exit_net(struct net *net)
1567 {
1568         struct sit_net *sitn = net_generic(net, sit_net_id);
1569         LIST_HEAD(list);
1570
1571         rtnl_lock();
1572         sit_destroy_tunnels(sitn, &list);
1573         unregister_netdevice_queue(sitn->fb_tunnel_dev, &list);
1574         unregister_netdevice_many(&list);
1575         rtnl_unlock();
1576 }
1577
1578 static struct pernet_operations sit_net_ops = {
1579         .init = sit_init_net,
1580         .exit = sit_exit_net,
1581         .id   = &sit_net_id,
1582         .size = sizeof(struct sit_net),
1583 };
1584
1585 static void __exit sit_cleanup(void)
1586 {
1587         rtnl_link_unregister(&sit_link_ops);
1588         xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1589
1590         unregister_pernet_device(&sit_net_ops);
1591         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1592 }
1593
1594 static int __init sit_init(void)
1595 {
1596         int err;
1597
1598         pr_info("IPv6 over IPv4 tunneling driver\n");
1599
1600         err = register_pernet_device(&sit_net_ops);
1601         if (err < 0)
1602                 return err;
1603         err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
1604         if (err < 0) {
1605                 pr_info("%s: can't add protocol\n", __func__);
1606                 goto xfrm_tunnel_failed;
1607         }
1608         err = rtnl_link_register(&sit_link_ops);
1609         if (err < 0)
1610                 goto rtnl_link_failed;
1611
1612 out:
1613         return err;
1614
1615 rtnl_link_failed:
1616         xfrm4_tunnel_deregister(&sit_handler, AF_INET6);
1617 xfrm_tunnel_failed:
1618         unregister_pernet_device(&sit_net_ops);
1619         goto out;
1620 }
1621
1622 module_init(sit_init);
1623 module_exit(sit_cleanup);
1624 MODULE_LICENSE("GPL");
1625 MODULE_ALIAS_NETDEV("sit0");