net/ipv6/ip6_tunnel.c

   1 /*
   2  *      IPv6 tunneling device
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Ville Nuorvala          <vnuorval@tcs.hut.fi>
   7  *      Yasuyuki Kozakai        <kozakai@linux-ipv6.org>
   8  *
   9  *      $Id$
  10  *
  11  *      Based on:
  12  *      linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c
  13  *
  14  *      RFC 2473
  15  *
  16  *      This program is free software; you can redistribute it and/or
  17  *      modify it under the terms of the GNU General Public License
  18  *      as published by the Free Software Foundation; either version
  19  *      2 of the License, or (at your option) any later version.
  20  *
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/capability.h>
  25 #include <linux/errno.h>
  26 #include <linux/types.h>
  27 #include <linux/sockios.h>
  28 #include <linux/icmp.h>
  29 #include <linux/if.h>
  30 #include <linux/in.h>
  31 #include <linux/ip.h>
  32 #include <linux/if_tunnel.h>
  33 #include <linux/net.h>
  34 #include <linux/in6.h>
  35 #include <linux/netdevice.h>
  36 #include <linux/if_arp.h>
  37 #include <linux/icmpv6.h>
  38 #include <linux/init.h>
  39 #include <linux/route.h>
  40 #include <linux/rtnetlink.h>
  41 #include <linux/netfilter_ipv6.h>
  42
  43 #include <asm/uaccess.h>
  44 #include <asm/atomic.h>
  45
  46 #include <net/icmp.h>
  47 #include <net/ip.h>
  48 #include <net/ipv6.h>
  49 #include <net/ip6_route.h>
  50 #include <net/addrconf.h>
  51 #include <net/ip6_tunnel.h>
  52 #include <net/xfrm.h>
  53 #include <net/dsfield.h>
  54 #include <net/inet_ecn.h>
  55
  56 MODULE_AUTHOR("Ville Nuorvala");
  57 MODULE_DESCRIPTION("IPv6 tunneling device");
  58 MODULE_LICENSE("GPL");
  59
  60 #define IPV6_TLV_TEL_DST_SIZE 8
  61
  62 #ifdef IP6_TNL_DEBUG
  63 #define IP6_TNL_TRACE(x...) printk(KERN_DEBUG "%s:" x "\n", __FUNCTION__)
  64 #else
  65 #define IP6_TNL_TRACE(x...) do {;} while(0)
  66 #endif
  67
  68 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK)
  69 #define IPV6_TCLASS_SHIFT 20
  70
  71 #define HASH_SIZE  32
  72
  73 #define HASH(addr) ((__force u32)((addr)->s6_addr32[0] ^ (addr)->s6_addr32[1] ^ \
  74                      (addr)->s6_addr32[2] ^ (addr)->s6_addr32[3]) & \
  75                     (HASH_SIZE - 1))
  76
  77 static int ip6_fb_tnl_dev_init(struct net_device *dev);
  78 static int ip6_tnl_dev_init(struct net_device *dev);
  79 static void ip6_tnl_dev_setup(struct net_device *dev);
  80
  81 /* the IPv6 tunnel fallback device */
  82 static struct net_device *ip6_fb_tnl_dev;
  83
  84
  85 /* lists for storing tunnels in use */
  86 static struct ip6_tnl *tnls_r_l[HASH_SIZE];
  87 static struct ip6_tnl *tnls_wc[1];
  88 static struct ip6_tnl **tnls[2] = { tnls_wc, tnls_r_l };
  89
  90 /* lock for the tunnel lists */
  91 static DEFINE_RWLOCK(ip6_tnl_lock);
  92
  93 static inline struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t)
  94 {
  95         struct dst_entry *dst = t->dst_cache;
  96
  97         if (dst && dst->obsolete &&
  98             dst->ops->check(dst, t->dst_cookie) == NULL) {
  99                 t->dst_cache = NULL;
 100                 dst_release(dst);
 101                 return NULL;
 102         }
 103
 104         return dst;
 105 }
 106
 107 static inline void ip6_tnl_dst_reset(struct ip6_tnl *t)
 108 {
 109         dst_release(t->dst_cache);
 110         t->dst_cache = NULL;
 111 }
 112
 113 static inline void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst)
 114 {
 115         struct rt6_info *rt = (struct rt6_info *) dst;
 116         t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0;
 117         dst_release(t->dst_cache);
 118         t->dst_cache = dst;
 119 }
 120
 121 /**
 122  * ip6_tnl_lookup - fetch tunnel matching the end-point addresses
 123  *   @remote: the address of the tunnel exit-point
 124  *   @local: the address of the tunnel entry-point
 125  *
 126  * Return:
 127  *   tunnel matching given end-points if found,
 128  *   else fallback tunnel if its device is up,
 129  *   else %NULL
 130  **/
 131
 132 static struct ip6_tnl *
 133 ip6_tnl_lookup(struct in6_addr *remote, struct in6_addr *local)
 134 {
 135         unsigned h0 = HASH(remote);
 136         unsigned h1 = HASH(local);
 137         struct ip6_tnl *t;
 138
 139         for (t = tnls_r_l[h0 ^ h1]; t; t = t->next) {
 140                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 141                     ipv6_addr_equal(remote, &t->parms.raddr) &&
 142                     (t->dev->flags & IFF_UP))
 143                         return t;
 144         }
 145         if ((t = tnls_wc[0]) != NULL && (t->dev->flags & IFF_UP))
 146                 return t;
 147
 148         return NULL;
 149 }
 150
 151 /**
 152  * ip6_tnl_bucket - get head of list matching given tunnel parameters
 153  *   @p: parameters containing tunnel end-points
 154  *
 155  * Description:
 156  *   ip6_tnl_bucket() returns the head of the list matching the
 157  *   &struct in6_addr entries laddr and raddr in @p.
 158  *
 159  * Return: head of IPv6 tunnel list
 160  **/
 161
 162 static struct ip6_tnl **
 163 ip6_tnl_bucket(struct ip6_tnl_parm *p)
 164 {
 165         struct in6_addr *remote = &p->raddr;
 166         struct in6_addr *local = &p->laddr;
 167         unsigned h = 0;
 168         int prio = 0;
 169
 170         if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) {
 171                 prio = 1;
 172                 h = HASH(remote) ^ HASH(local);
 173         }
 174         return &tnls[prio][h];
 175 }
 176
 177 /**
 178  * ip6_tnl_link - add tunnel to hash table
 179  *   @t: tunnel to be added
 180  **/
 181
 182 static void
 183 ip6_tnl_link(struct ip6_tnl *t)
 184 {
 185         struct ip6_tnl **tp = ip6_tnl_bucket(&t->parms);
 186
 187         t->next = *tp;
 188         write_lock_bh(&ip6_tnl_lock);
 189         *tp = t;
 190         write_unlock_bh(&ip6_tnl_lock);
 191 }
 192
 193 /**
 194  * ip6_tnl_unlink - remove tunnel from hash table
 195  *   @t: tunnel to be removed
 196  **/
 197
 198 static void
 199 ip6_tnl_unlink(struct ip6_tnl *t)
 200 {
 201         struct ip6_tnl **tp;
 202
 203         for (tp = ip6_tnl_bucket(&t->parms); *tp; tp = &(*tp)->next) {
 204                 if (t == *tp) {
 205                         write_lock_bh(&ip6_tnl_lock);
 206                         *tp = t->next;
 207                         write_unlock_bh(&ip6_tnl_lock);
 208                         break;
 209                 }
 210         }
 211 }
 212
 213 /**
 214  * ip6_tnl_create() - create a new tunnel
 215  *   @p: tunnel parameters
 216  *   @pt: pointer to new tunnel
 217  *
 218  * Description:
 219  *   Create tunnel matching given parameters.
 220  *
 221  * Return:
 222  *   created tunnel or NULL
 223  **/
 224
 225 static struct ip6_tnl *ip6_tnl_create(struct ip6_tnl_parm *p)
 226 {
 227         struct net_device *dev;
 228         struct ip6_tnl *t;
 229         char name[IFNAMSIZ];
 230         int err;
 231
 232         if (p->name[0]) {
 233                 strlcpy(name, p->name, IFNAMSIZ);
 234         } else {
 235                 int i;
 236                 for (i = 1; i < IP6_TNL_MAX; i++) {
 237                         sprintf(name, "ip6tnl%d", i);
 238                         if (__dev_get_by_name(name) == NULL)
 239                                 break;
 240                 }
 241                 if (i == IP6_TNL_MAX)
 242                         goto failed;
 243         }
 244         dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup);
 245         if (dev == NULL)
 246                 goto failed;
 247
 248         t = netdev_priv(dev);
 249         dev->init = ip6_tnl_dev_init;
 250         t->parms = *p;
 251
 252         if ((err = register_netdevice(dev)) < 0) {
 253                 free_netdev(dev);
 254                 goto failed;
 255         }
 256         dev_hold(dev);
 257         ip6_tnl_link(t);
 258         return t;
 259 failed:
 260         return NULL;
 261 }
 262
 263 /**
 264  * ip6_tnl_locate - find or create tunnel matching given parameters
 265  *   @p: tunnel parameters
 266  *   @create: != 0 if allowed to create new tunnel if no match found
 267  *
 268  * Description:
 269  *   ip6_tnl_locate() first tries to locate an existing tunnel
 270  *   based on @parms. If this is unsuccessful, but @create is set a new
 271  *   tunnel device is created and registered for use.
 272  *
 273  * Return:
 274  *   matching tunnel or NULL
 275  **/
 276
 277 static struct ip6_tnl *ip6_tnl_locate(struct ip6_tnl_parm *p, int create)
 278 {
 279         struct in6_addr *remote = &p->raddr;
 280         struct in6_addr *local = &p->laddr;
 281         struct ip6_tnl *t;
 282
 283         for (t = *ip6_tnl_bucket(p); t; t = t->next) {
 284                 if (ipv6_addr_equal(local, &t->parms.laddr) &&
 285                     ipv6_addr_equal(remote, &t->parms.raddr))
 286                         return t;
 287         }
 288         if (!create)
 289                 return NULL;
 290         return ip6_tnl_create(p);
 291 }
 292
 293 /**
 294  * ip6_tnl_dev_uninit - tunnel device uninitializer
 295  *   @dev: the device to be destroyed
 296  *
 297  * Description:
 298  *   ip6_tnl_dev_uninit() removes tunnel from its list
 299  **/
 300
 301 static void
 302 ip6_tnl_dev_uninit(struct net_device *dev)
 303 {
 304         struct ip6_tnl *t = netdev_priv(dev);
 305
 306         if (dev == ip6_fb_tnl_dev) {
 307                 write_lock_bh(&ip6_tnl_lock);
 308                 tnls_wc[0] = NULL;
 309                 write_unlock_bh(&ip6_tnl_lock);
 310         } else {
 311                 ip6_tnl_unlink(t);
 312         }
 313         ip6_tnl_dst_reset(t);
 314         dev_put(dev);
 315 }
 316
 317 /**
 318  * parse_tvl_tnl_enc_lim - handle encapsulation limit option
 319  *   @skb: received socket buffer
 320  *
 321  * Return:
 322  *   0 if none was found,
 323  *   else index to encapsulation limit
 324  **/
 325
 326 static __u16
 327 parse_tlv_tnl_enc_lim(struct sk_buff *skb, __u8 * raw)
 328 {
 329         struct ipv6hdr *ipv6h = (struct ipv6hdr *) raw;
 330         __u8 nexthdr = ipv6h->nexthdr;
 331         __u16 off = sizeof (*ipv6h);
 332
 333         while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) {
 334                 __u16 optlen = 0;
 335                 struct ipv6_opt_hdr *hdr;
 336                 if (raw + off + sizeof (*hdr) > skb->data &&
 337                     !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr)))
 338                         break;
 339
 340                 hdr = (struct ipv6_opt_hdr *) (raw + off);
 341                 if (nexthdr == NEXTHDR_FRAGMENT) {
 342                         struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr;
 343                         if (frag_hdr->frag_off)
 344                                 break;
 345                         optlen = 8;
 346                 } else if (nexthdr == NEXTHDR_AUTH) {
 347                         optlen = (hdr->hdrlen + 2) << 2;
 348                 } else {
 349                         optlen = ipv6_optlen(hdr);
 350                 }
 351                 if (nexthdr == NEXTHDR_DEST) {
 352                         __u16 i = off + 2;
 353                         while (1) {
 354                                 struct ipv6_tlv_tnl_enc_lim *tel;
 355
 356                                 /* No more room for encapsulation limit */
 357                                 if (i + sizeof (*tel) > off + optlen)
 358                                         break;
 359
 360                                 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i];
 361                                 /* return index of option if found and valid */
 362                                 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT &&
 363                                     tel->length == 1)
 364                                         return i;
 365                                 /* else jump to next option */
 366                                 if (tel->type)
 367                                         i += tel->length + 2;
 368                                 else
 369                                         i++;
 370                         }
 371                 }
 372                 nexthdr = hdr->nexthdr;
 373                 off += optlen;
 374         }
 375         return 0;
 376 }
 377
 378 /**
 379  * ip6_tnl_err - tunnel error handler
 380  *
 381  * Description:
 382  *   ip6_tnl_err() should handle errors in the tunnel according
 383  *   to the specifications in RFC 2473.
 384  **/
 385
 386 static int
 387 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
 388             int *type, int *code, int *msg, __be32 *info, int offset)
 389 {
 390         struct ipv6hdr *ipv6h = (struct ipv6hdr *) skb->data;
 391         struct ip6_tnl *t;
 392         int rel_msg = 0;
 393         int rel_type = ICMPV6_DEST_UNREACH;
 394         int rel_code = ICMPV6_ADDR_UNREACH;
 395         __u32 rel_info = 0;
 396         __u16 len;
 397         int err = -ENOENT;
 398
 399         /* If the packet doesn't contain the original IPv6 header we are
 400            in trouble since we might need the source address for further
 401            processing of the error. */
 402
 403         read_lock(&ip6_tnl_lock);
 404         if ((t = ip6_tnl_lookup(&ipv6h->daddr, &ipv6h->saddr)) == NULL)
 405                 goto out;
 406
 407         if (t->parms.proto != ipproto && t->parms.proto != 0)
 408                 goto out;
 409
 410         err = 0;
 411
 412         switch (*type) {
 413                 __u32 teli;
 414                 struct ipv6_tlv_tnl_enc_lim *tel;
 415                 __u32 mtu;
 416         case ICMPV6_DEST_UNREACH:
 417                 if (net_ratelimit())
 418                         printk(KERN_WARNING
 419                                "%s: Path to destination invalid "
 420                                "or inactive!\n", t->parms.name);
 421                 rel_msg = 1;
 422                 break;
 423         case ICMPV6_TIME_EXCEED:
 424                 if ((*code) == ICMPV6_EXC_HOPLIMIT) {
 425                         if (net_ratelimit())
 426                                 printk(KERN_WARNING
 427                                        "%s: Too small hop limit or "
 428                                        "routing loop in tunnel!\n",
 429                                        t->parms.name);
 430                         rel_msg = 1;
 431                 }
 432                 break;
 433         case ICMPV6_PARAMPROB:
 434                 teli = 0;
 435                 if ((*code) == ICMPV6_HDR_FIELD)
 436                         teli = parse_tlv_tnl_enc_lim(skb, skb->data);
 437
 438                 if (teli && teli == ntohl(*info) - 2) {
 439                         tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 440                         if (tel->encap_limit == 0) {
 441                                 if (net_ratelimit())
 442                                         printk(KERN_WARNING
 443                                                "%s: Too small encapsulation "
 444                                                "limit or routing loop in "
 445                                                "tunnel!\n", t->parms.name);
 446                                 rel_msg = 1;
 447                         }
 448                 } else if (net_ratelimit()) {
 449                         printk(KERN_WARNING
 450                                "%s: Recipient unable to parse tunneled "
 451                                "packet!\n ", t->parms.name);
 452                 }
 453                 break;
 454         case ICMPV6_PKT_TOOBIG:
 455                 mtu = ntohl(*info) - offset;
 456                 if (mtu < IPV6_MIN_MTU)
 457                         mtu = IPV6_MIN_MTU;
 458                 t->dev->mtu = mtu;
 459
 460                 if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) {
 461                         rel_type = ICMPV6_PKT_TOOBIG;
 462                         rel_code = 0;
 463                         rel_info = mtu;
 464                         rel_msg = 1;
 465                 }
 466                 break;
 467         }
 468
 469         *type = rel_type;
 470         *code = rel_code;
 471         *info = rel_info;
 472         *msg = rel_msg;
 473
 474 out:
 475         read_unlock(&ip6_tnl_lock);
 476         return err;
 477 }
 478
 479 static int
 480 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 481            int type, int code, int offset, __u32 info)
 482 {
 483         int rel_msg = 0;
 484         int rel_type = type;
 485         int rel_code = code;
 486         __u32 rel_info = info;
 487         int err;
 488         struct sk_buff *skb2;
 489         struct iphdr *eiph;
 490         struct flowi fl;
 491         struct rtable *rt;
 492
 493         err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code,
 494                           &rel_msg, &rel_info, offset);
 495         if (err < 0)
 496                 return err;
 497
 498         if (rel_msg == 0)
 499                 return 0;
 500
 501         switch (rel_type) {
 502         case ICMPV6_DEST_UNREACH:
 503                 if (rel_code != ICMPV6_ADDR_UNREACH)
 504                         return 0;
 505                 rel_type = ICMP_DEST_UNREACH;
 506                 rel_code = ICMP_HOST_UNREACH;
 507                 break;
 508         case ICMPV6_PKT_TOOBIG:
 509                 if (rel_code != 0)
 510                         return 0;
 511                 rel_type = ICMP_DEST_UNREACH;
 512                 rel_code = ICMP_FRAG_NEEDED;
 513                 break;
 514         default:
 515                 return 0;
 516         }
 517
 518         if (!pskb_may_pull(skb, offset + sizeof(struct iphdr)))
 519                 return 0;
 520
 521         skb2 = skb_clone(skb, GFP_ATOMIC);
 522         if (!skb2)
 523                 return 0;
 524
 525         dst_release(skb2->dst);
 526         skb2->dst = NULL;
 527         skb_pull(skb2, offset);
 528         skb_reset_network_header(skb2);
 529         eiph = ip_hdr(skb2);
 530
 531         /* Try to guess incoming interface */
 532         memset(&fl, 0, sizeof(fl));
 533         fl.fl4_dst = eiph->saddr;
 534         fl.fl4_tos = RT_TOS(eiph->tos);
 535         fl.proto = IPPROTO_IPIP;
 536         if (ip_route_output_key(&rt, &fl))
 537                 goto out;
 538
 539         skb2->dev = rt->u.dst.dev;
 540
 541         /* route "incoming" packet */
 542         if (rt->rt_flags & RTCF_LOCAL) {
 543                 ip_rt_put(rt);
 544                 rt = NULL;
 545                 fl.fl4_dst = eiph->daddr;
 546                 fl.fl4_src = eiph->saddr;
 547                 fl.fl4_tos = eiph->tos;
 548                 if (ip_route_output_key(&rt, &fl) ||
 549                     rt->u.dst.dev->type != ARPHRD_TUNNEL) {
 550                         ip_rt_put(rt);
 551                         goto out;
 552                 }
 553         } else {
 554                 ip_rt_put(rt);
 555                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
 556                                    skb2->dev) ||
 557                     skb2->dst->dev->type != ARPHRD_TUNNEL)
 558                         goto out;
 559         }
 560
 561         /* change mtu on this route */
 562         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
 563                 if (rel_info > dst_mtu(skb2->dst))
 564                         goto out;
 565
 566                 skb2->dst->ops->update_pmtu(skb2->dst, rel_info);
 567                 rel_info = htonl(rel_info);
 568         }
 569
 570         icmp_send(skb2, rel_type, rel_code, rel_info);
 571
 572 out:
 573         kfree_skb(skb2);
 574         return 0;
 575 }
 576
 577 static int
 578 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 579            int type, int code, int offset, __u32 info)
 580 {
 581         int rel_msg = 0;
 582         int rel_type = type;
 583         int rel_code = code;
 584         __u32 rel_info = info;
 585         int err;
 586
 587         err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
 588                           &rel_msg, &rel_info, offset);
 589         if (err < 0)
 590                 return err;
 591
 592         if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) {
 593                 struct rt6_info *rt;
 594                 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 595
 596                 if (!skb2)
 597                         return 0;
 598
 599                 dst_release(skb2->dst);
 600                 skb2->dst = NULL;
 601                 skb_pull(skb2, offset);
 602                 skb_reset_network_header(skb2);
 603
 604                 /* Try to guess incoming interface */
 605                 rt = rt6_lookup(&ipv6_hdr(skb2)->saddr, NULL, 0, 0);
 606
 607                 if (rt && rt->rt6i_dev)
 608                         skb2->dev = rt->rt6i_dev;
 609
 610                 icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev);
 611
 612                 if (rt)
 613                         dst_release(&rt->u.dst);
 614
 615                 kfree_skb(skb2);
 616         }
 617
 618         return 0;
 619 }
 620
 621 static void ip4ip6_dscp_ecn_decapsulate(struct ip6_tnl *t,
 622                                         struct ipv6hdr *ipv6h,
 623                                         struct sk_buff *skb)
 624 {
 625         __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK;
 626
 627         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 628                 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield);
 629
 630         if (INET_ECN_is_ce(dsfield))
 631                 IP_ECN_set_ce(ip_hdr(skb));
 632 }
 633
 634 static void ip6ip6_dscp_ecn_decapsulate(struct ip6_tnl *t,
 635                                         struct ipv6hdr *ipv6h,
 636                                         struct sk_buff *skb)
 637 {
 638         if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY)
 639                 ipv6_copy_dscp(ipv6h, ipv6_hdr(skb));
 640
 641         if (INET_ECN_is_ce(ipv6_get_dsfield(ipv6h)))
 642                 IP6_ECN_set_ce(ipv6_hdr(skb));
 643 }
 644
 645 static inline int ip6_tnl_rcv_ctl(struct ip6_tnl *t)
 646 {
 647         struct ip6_tnl_parm *p = &t->parms;
 648         int ret = 0;
 649
 650         if (p->flags & IP6_TNL_F_CAP_RCV) {
 651                 struct net_device *ldev = NULL;
 652
 653                 if (p->link)
 654                         ldev = dev_get_by_index(p->link);
 655
 656                 if ((ipv6_addr_is_multicast(&p->laddr) ||
 657                      likely(ipv6_chk_addr(&p->laddr, ldev, 0))) &&
 658                     likely(!ipv6_chk_addr(&p->raddr, NULL, 0)))
 659                         ret = 1;
 660
 661                 if (ldev)
 662                         dev_put(ldev);
 663         }
 664         return ret;
 665 }
 666
 667 /**
 668  * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally
 669  *   @skb: received socket buffer
 670  *   @protocol: ethernet protocol ID
 671  *   @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN
 672  *
 673  * Return: 0
 674  **/
 675
 676 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
 677                        __u8 ipproto,
 678                        void (*dscp_ecn_decapsulate)(struct ip6_tnl *t,
 679                                                     struct ipv6hdr *ipv6h,
 680                                                     struct sk_buff *skb))
 681 {
 682         struct ip6_tnl *t;
 683         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 684
 685         read_lock(&ip6_tnl_lock);
 686
 687         if ((t = ip6_tnl_lookup(&ipv6h->saddr, &ipv6h->daddr)) != NULL) {
 688                 if (t->parms.proto != ipproto && t->parms.proto != 0) {
 689                         read_unlock(&ip6_tnl_lock);
 690                         goto discard;
 691                 }
 692
 693                 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
 694                         read_unlock(&ip6_tnl_lock);
 695                         goto discard;
 696                 }
 697
 698                 if (!ip6_tnl_rcv_ctl(t)) {
 699                         t->stat.rx_dropped++;
 700                         read_unlock(&ip6_tnl_lock);
 701                         goto discard;
 702                 }
 703                 secpath_reset(skb);
 704                 skb->mac_header = skb->network_header;
 705                 skb_reset_network_header(skb);
 706                 skb->protocol = htons(protocol);
 707                 skb->pkt_type = PACKET_HOST;
 708                 memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
 709                 skb->dev = t->dev;
 710                 dst_release(skb->dst);
 711                 skb->dst = NULL;
 712                 nf_reset(skb);
 713
 714                 dscp_ecn_decapsulate(t, ipv6h, skb);
 715
 716                 t->stat.rx_packets++;
 717                 t->stat.rx_bytes += skb->len;
 718                 netif_rx(skb);
 719                 read_unlock(&ip6_tnl_lock);
 720                 return 0;
 721         }
 722         read_unlock(&ip6_tnl_lock);
 723         return 1;
 724
 725 discard:
 726         kfree_skb(skb);
 727         return 0;
 728 }
 729
 730 static int ip4ip6_rcv(struct sk_buff *skb)
 731 {
 732         return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP,
 733                            ip4ip6_dscp_ecn_decapsulate);
 734 }
 735
 736 static int ip6ip6_rcv(struct sk_buff *skb)
 737 {
 738         return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6,
 739                            ip6ip6_dscp_ecn_decapsulate);
 740 }
 741
 742 struct ipv6_tel_txoption {
 743         struct ipv6_txoptions ops;
 744         __u8 dst_opt[8];
 745 };
 746
 747 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit)
 748 {
 749         memset(opt, 0, sizeof(struct ipv6_tel_txoption));
 750
 751         opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT;
 752         opt->dst_opt[3] = 1;
 753         opt->dst_opt[4] = encap_limit;
 754         opt->dst_opt[5] = IPV6_TLV_PADN;
 755         opt->dst_opt[6] = 1;
 756
 757         opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt;
 758         opt->ops.opt_nflen = 8;
 759 }
 760
 761 /**
 762  * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own
 763  *   @t: the outgoing tunnel device
 764  *   @hdr: IPv6 header from the incoming packet
 765  *
 766  * Description:
 767  *   Avoid trivial tunneling loop by checking that tunnel exit-point
 768  *   doesn't match source of incoming packet.
 769  *
 770  * Return:
 771  *   1 if conflict,
 772  *   0 else
 773  **/
 774
 775 static inline int
 776 ip6_tnl_addr_conflict(struct ip6_tnl *t, struct ipv6hdr *hdr)
 777 {
 778         return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr);
 779 }
 780
 781 static inline int ip6_tnl_xmit_ctl(struct ip6_tnl *t)
 782 {
 783         struct ip6_tnl_parm *p = &t->parms;
 784         int ret = 0;
 785
 786         if (p->flags & IP6_TNL_F_CAP_XMIT) {
 787                 struct net_device *ldev = NULL;
 788
 789                 if (p->link)
 790                         ldev = dev_get_by_index(p->link);
 791
 792                 if (unlikely(!ipv6_chk_addr(&p->laddr, ldev, 0)))
 793                         printk(KERN_WARNING
 794                                "%s xmit: Local address not yet configured!\n",
 795                                p->name);
 796                 else if (!ipv6_addr_is_multicast(&p->raddr) &&
 797                          unlikely(ipv6_chk_addr(&p->raddr, NULL, 0)))
 798                         printk(KERN_WARNING
 799                                "%s xmit: Routing loop! "
 800                                "Remote address found on this node!\n",
 801                                p->name);
 802                 else
 803                         ret = 1;
 804                 if (ldev)
 805                         dev_put(ldev);
 806         }
 807         return ret;
 808 }
 809 /**
 810  * ip6_tnl_xmit2 - encapsulate packet and send
 811  *   @skb: the outgoing socket buffer
 812  *   @dev: the outgoing tunnel device
 813  *   @dsfield: dscp code for outer header
 814  *   @fl: flow of tunneled packet
 815  *   @encap_limit: encapsulation limit
 816  *   @pmtu: Path MTU is stored if packet is too big
 817  *
 818  * Description:
 819  *   Build new header and do some sanity checks on the packet before sending
 820  *   it.
 821  *
 822  * Return:
 823  *   0 on success
 824  *   -1 fail
 825  *   %-EMSGSIZE message too big. return mtu in this case.
 826  **/
 827
 828 static int ip6_tnl_xmit2(struct sk_buff *skb,
 829                          struct net_device *dev,
 830                          __u8 dsfield,
 831                          struct flowi *fl,
 832                          int encap_limit,
 833                          __u32 *pmtu)
 834 {
 835         struct ip6_tnl *t = netdev_priv(dev);
 836         struct net_device_stats *stats = &t->stat;
 837         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 838         struct ipv6_tel_txoption opt;
 839         struct dst_entry *dst;
 840         struct net_device *tdev;
 841         int mtu;
 842         int max_headroom = sizeof(struct ipv6hdr);
 843         u8 proto;
 844         int err = -1;
 845         int pkt_len;
 846
 847         if ((dst = ip6_tnl_dst_check(t)) != NULL)
 848                 dst_hold(dst);
 849         else {
 850                 dst = ip6_route_output(NULL, fl);
 851
 852                 if (dst->error || xfrm_lookup(&dst, fl, NULL, 0) < 0)
 853                         goto tx_err_link_failure;
 854         }
 855
 856         tdev = dst->dev;
 857
 858         if (tdev == dev) {
 859                 stats->collisions++;
 860                 if (net_ratelimit())
 861                         printk(KERN_WARNING
 862                                "%s: Local routing loop detected!\n",
 863                                t->parms.name);
 864                 goto tx_err_dst_release;
 865         }
 866         mtu = dst_mtu(dst) - sizeof (*ipv6h);
 867         if (encap_limit >= 0) {
 868                 max_headroom += 8;
 869                 mtu -= 8;
 870         }
 871         if (mtu < IPV6_MIN_MTU)
 872                 mtu = IPV6_MIN_MTU;
 873         if (skb->dst)
 874                 skb->dst->ops->update_pmtu(skb->dst, mtu);
 875         if (skb->len > mtu) {
 876                 *pmtu = mtu;
 877                 err = -EMSGSIZE;
 878                 goto tx_err_dst_release;
 879         }
 880
 881         /*
 882          * Okay, now see if we can stuff it in the buffer as-is.
 883          */
 884         max_headroom += LL_RESERVED_SPACE(tdev);
 885
 886         if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
 887             (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
 888                 struct sk_buff *new_skb;
 889
 890                 if (!(new_skb = skb_realloc_headroom(skb, max_headroom)))
 891                         goto tx_err_dst_release;
 892
 893                 if (skb->sk)
 894                         skb_set_owner_w(new_skb, skb->sk);
 895                 kfree_skb(skb);
 896                 skb = new_skb;
 897         }
 898         dst_release(skb->dst);
 899         skb->dst = dst_clone(dst);
 900
 901         skb->transport_header = skb->network_header;
 902
 903         proto = fl->proto;
 904         if (encap_limit >= 0) {
 905                 init_tel_txopt(&opt, encap_limit);
 906                 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL);
 907         }
 908         skb_push(skb, sizeof(struct ipv6hdr));
 909         skb_reset_network_header(skb);
 910         ipv6h = ipv6_hdr(skb);
 911         *(__be32*)ipv6h = fl->fl6_flowlabel | htonl(0x60000000);
 912         dsfield = INET_ECN_encapsulate(0, dsfield);
 913         ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield);
 914         ipv6h->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
 915         ipv6h->hop_limit = t->parms.hop_limit;
 916         ipv6h->nexthdr = proto;
 917         ipv6_addr_copy(&ipv6h->saddr, &fl->fl6_src);
 918         ipv6_addr_copy(&ipv6h->daddr, &fl->fl6_dst);
 919         nf_reset(skb);
 920         pkt_len = skb->len;
 921         err = NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL,
 922                       skb->dst->dev, dst_output);
 923
 924         if (net_xmit_eval(err) == 0) {
 925                 stats->tx_bytes += pkt_len;
 926                 stats->tx_packets++;
 927         } else {
 928                 stats->tx_errors++;
 929                 stats->tx_aborted_errors++;
 930         }
 931         ip6_tnl_dst_store(t, dst);
 932         return 0;
 933 tx_err_link_failure:
 934         stats->tx_carrier_errors++;
 935         dst_link_failure(skb);
 936 tx_err_dst_release:
 937         dst_release(dst);
 938         return err;
 939 }
 940
 941 static inline int
 942 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 943 {
 944         struct ip6_tnl *t = netdev_priv(dev);
 945         struct iphdr  *iph = ip_hdr(skb);
 946         int encap_limit = -1;
 947         struct flowi fl;
 948         __u8 dsfield;
 949         __u32 mtu;
 950         int err;
 951
 952         if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) ||
 953             !ip6_tnl_xmit_ctl(t))
 954                 return -1;
 955
 956         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 957                 encap_limit = t->parms.encap_limit;
 958
 959         memcpy(&fl, &t->fl, sizeof (fl));
 960         fl.proto = IPPROTO_IPIP;
 961
 962         dsfield = ipv4_get_dsfield(iph);
 963
 964         if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS))
 965                 fl.fl6_flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
 966                                           & IPV6_TCLASS_MASK;
 967
 968         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu);
 969         if (err != 0) {
 970                 /* XXX: send ICMP error even if DF is not set. */
 971                 if (err == -EMSGSIZE)
 972                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 973                                   htonl(mtu));
 974                 return -1;
 975         }
 976
 977         return 0;
 978 }
 979
 980 static inline int
 981 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 982 {
 983         struct ip6_tnl *t = netdev_priv(dev);
 984         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 985         int encap_limit = -1;
 986         __u16 offset;
 987         struct flowi fl;
 988         __u8 dsfield;
 989         __u32 mtu;
 990         int err;
 991
 992         if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
 993             !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h))
 994                 return -1;
 995
 996         offset = parse_tlv_tnl_enc_lim(skb, skb_network_header(skb));
 997         if (offset > 0) {
 998                 struct ipv6_tlv_tnl_enc_lim *tel;
 999                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
1000                 if (tel->encap_limit == 0) {
1001                         icmpv6_send(skb, ICMPV6_PARAMPROB,
1002                                     ICMPV6_HDR_FIELD, offset + 2, skb->dev);
1003                         return -1;
1004                 }
1005                 encap_limit = tel->encap_limit - 1;
1006         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1007                 encap_limit = t->parms.encap_limit;
1008
1009         memcpy(&fl, &t->fl, sizeof (fl));
1010         fl.proto = IPPROTO_IPV6;
1011
1012         dsfield = ipv6_get_dsfield(ipv6h);
1013         if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS))
1014                 fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
1015         if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL))
1016                 fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK);
1017
1018         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu);
1019         if (err != 0) {
1020                 if (err == -EMSGSIZE)
1021                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
1022                 return -1;
1023         }
1024
1025         return 0;
1026 }
1027
1028 static int
1029 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1030 {
1031         struct ip6_tnl *t = netdev_priv(dev);
1032         struct net_device_stats *stats = &t->stat;
1033         int ret;
1034
1035         if (t->recursion++) {
1036                 t->stat.collisions++;
1037                 goto tx_err;
1038         }
1039
1040         switch (skb->protocol) {
1041         case __constant_htons(ETH_P_IP):
1042                 ret = ip4ip6_tnl_xmit(skb, dev);
1043                 break;
1044         case __constant_htons(ETH_P_IPV6):
1045                 ret = ip6ip6_tnl_xmit(skb, dev);
1046                 break;
1047         default:
1048                 goto tx_err;
1049         }
1050
1051         if (ret < 0)
1052                 goto tx_err;
1053
1054         t->recursion--;
1055         return 0;
1056
1057 tx_err:
1058         stats->tx_errors++;
1059         stats->tx_dropped++;
1060         kfree_skb(skb);
1061         t->recursion--;
1062         return 0;
1063 }
1064
1065 static void ip6_tnl_set_cap(struct ip6_tnl *t)
1066 {
1067         struct ip6_tnl_parm *p = &t->parms;
1068         int ltype = ipv6_addr_type(&p->laddr);
1069         int rtype = ipv6_addr_type(&p->raddr);
1070
1071         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV);
1072
1073         if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
1074             rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
1075             !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
1076             (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
1077                 if (ltype&IPV6_ADDR_UNICAST)
1078                         p->flags |= IP6_TNL_F_CAP_XMIT;
1079                 if (rtype&IPV6_ADDR_UNICAST)
1080                         p->flags |= IP6_TNL_F_CAP_RCV;
1081         }
1082 }
1083
1084 static void ip6_tnl_link_config(struct ip6_tnl *t)
1085 {
1086         struct net_device *dev = t->dev;
1087         struct ip6_tnl_parm *p = &t->parms;
1088         struct flowi *fl = &t->fl;
1089
1090         memcpy(&dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1091         memcpy(&dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1092
1093         /* Set up flowi template */
1094         ipv6_addr_copy(&fl->fl6_src, &p->laddr);
1095         ipv6_addr_copy(&fl->fl6_dst, &p->raddr);
1096         fl->oif = p->link;
1097         fl->fl6_flowlabel = 0;
1098
1099         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1100                 fl->fl6_flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1101         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1102                 fl->fl6_flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1103
1104         ip6_tnl_set_cap(t);
1105
1106         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1107                 dev->flags |= IFF_POINTOPOINT;
1108         else
1109                 dev->flags &= ~IFF_POINTOPOINT;
1110
1111         dev->iflink = p->link;
1112
1113         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1114                 int strict = (ipv6_addr_type(&p->raddr) &
1115                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1116
1117                 struct rt6_info *rt = rt6_lookup(&p->raddr, &p->laddr,
1118                                                  p->link, strict);
1119
1120                 if (rt == NULL)
1121                         return;
1122
1123                 if (rt->rt6i_dev) {
1124                         dev->hard_header_len = rt->rt6i_dev->hard_header_len +
1125                                 sizeof (struct ipv6hdr);
1126
1127                         dev->mtu = rt->rt6i_dev->mtu - sizeof (struct ipv6hdr);
1128
1129                         if (dev->mtu < IPV6_MIN_MTU)
1130                                 dev->mtu = IPV6_MIN_MTU;
1131                 }
1132                 dst_release(&rt->u.dst);
1133         }
1134 }
1135
1136 /**
1137  * ip6_tnl_change - update the tunnel parameters
1138  *   @t: tunnel to be changed
1139  *   @p: tunnel configuration parameters
1140  *   @active: != 0 if tunnel is ready for use
1141  *
1142  * Description:
1143  *   ip6_tnl_change() updates the tunnel parameters
1144  **/
1145
1146 static int
1147 ip6_tnl_change(struct ip6_tnl *t, struct ip6_tnl_parm *p)
1148 {
1149         ipv6_addr_copy(&t->parms.laddr, &p->laddr);
1150         ipv6_addr_copy(&t->parms.raddr, &p->raddr);
1151         t->parms.flags = p->flags;
1152         t->parms.hop_limit = p->hop_limit;
1153         t->parms.encap_limit = p->encap_limit;
1154         t->parms.flowinfo = p->flowinfo;
1155         t->parms.link = p->link;
1156         t->parms.proto = p->proto;
1157         ip6_tnl_dst_reset(t);
1158         ip6_tnl_link_config(t);
1159         return 0;
1160 }
1161
1162 /**
1163  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1164  *   @dev: virtual device associated with tunnel
1165  *   @ifr: parameters passed from userspace
1166  *   @cmd: command to be performed
1167  *
1168  * Description:
1169  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1170  *   from userspace.
1171  *
1172  *   The possible commands are the following:
1173  *     %SIOCGETTUNNEL: get tunnel parameters for device
1174  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1175  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1176  *     %SIOCDELTUNNEL: delete tunnel
1177  *
1178  *   The fallback device "ip6tnl0", created during module
1179  *   initialization, can be used for creating other tunnel devices.
1180  *
1181  * Return:
1182  *   0 on success,
1183  *   %-EFAULT if unable to copy data to or from userspace,
1184  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1185  *   %-EINVAL if passed tunnel parameters are invalid,
1186  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1187  *   %-ENODEV if attempting to change or delete a nonexisting device
1188  **/
1189
1190 static int
1191 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1192 {
1193         int err = 0;
1194         struct ip6_tnl_parm p;
1195         struct ip6_tnl *t = NULL;
1196
1197         switch (cmd) {
1198         case SIOCGETTUNNEL:
1199                 if (dev == ip6_fb_tnl_dev) {
1200                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) {
1201                                 err = -EFAULT;
1202                                 break;
1203                         }
1204                         t = ip6_tnl_locate(&p, 0);
1205                 }
1206                 if (t == NULL)
1207                         t = netdev_priv(dev);
1208                 memcpy(&p, &t->parms, sizeof (p));
1209                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) {
1210                         err = -EFAULT;
1211                 }
1212                 break;
1213         case SIOCADDTUNNEL:
1214         case SIOCCHGTUNNEL:
1215                 err = -EPERM;
1216                 if (!capable(CAP_NET_ADMIN))
1217                         break;
1218                 err = -EFAULT;
1219                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1220                         break;
1221                 err = -EINVAL;
1222                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1223                     p.proto != 0)
1224                         break;
1225                 t = ip6_tnl_locate(&p, cmd == SIOCADDTUNNEL);
1226                 if (dev != ip6_fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
1227                         if (t != NULL) {
1228                                 if (t->dev != dev) {
1229                                         err = -EEXIST;
1230                                         break;
1231                                 }
1232                         } else
1233                                 t = netdev_priv(dev);
1234
1235                         ip6_tnl_unlink(t);
1236                         err = ip6_tnl_change(t, &p);
1237                         ip6_tnl_link(t);
1238                         netdev_state_change(dev);
1239                 }
1240                 if (t) {
1241                         err = 0;
1242                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof (p)))
1243                                 err = -EFAULT;
1244
1245                 } else
1246                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1247                 break;
1248         case SIOCDELTUNNEL:
1249                 err = -EPERM;
1250                 if (!capable(CAP_NET_ADMIN))
1251                         break;
1252
1253                 if (dev == ip6_fb_tnl_dev) {
1254                         err = -EFAULT;
1255                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1256                                 break;
1257                         err = -ENOENT;
1258                         if ((t = ip6_tnl_locate(&p, 0)) == NULL)
1259                                 break;
1260                         err = -EPERM;
1261                         if (t->dev == ip6_fb_tnl_dev)
1262                                 break;
1263                         dev = t->dev;
1264                 }
1265                 err = 0;
1266                 unregister_netdevice(dev);
1267                 break;
1268         default:
1269                 err = -EINVAL;
1270         }
1271         return err;
1272 }
1273
1274 /**
1275  * ip6_tnl_get_stats - return the stats for tunnel device
1276  *   @dev: virtual device associated with tunnel
1277  *
1278  * Return: stats for device
1279  **/
1280
1281 static struct net_device_stats *
1282 ip6_tnl_get_stats(struct net_device *dev)
1283 {
1284         return &(((struct ip6_tnl *)netdev_priv(dev))->stat);
1285 }
1286
1287 /**
1288  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1289  *   @dev: virtual device associated with tunnel
1290  *   @new_mtu: the new mtu
1291  *
1292  * Return:
1293  *   0 on success,
1294  *   %-EINVAL if mtu too small
1295  **/
1296
1297 static int
1298 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1299 {
1300         if (new_mtu < IPV6_MIN_MTU) {
1301                 return -EINVAL;
1302         }
1303         dev->mtu = new_mtu;
1304         return 0;
1305 }
1306
1307 /**
1308  * ip6_tnl_dev_setup - setup virtual tunnel device
1309  *   @dev: virtual device associated with tunnel
1310  *
1311  * Description:
1312  *   Initialize function pointers and device parameters
1313  **/
1314
1315 static void ip6_tnl_dev_setup(struct net_device *dev)
1316 {
1317         SET_MODULE_OWNER(dev);
1318         dev->uninit = ip6_tnl_dev_uninit;
1319         dev->destructor = free_netdev;
1320         dev->hard_start_xmit = ip6_tnl_xmit;
1321         dev->get_stats = ip6_tnl_get_stats;
1322         dev->do_ioctl = ip6_tnl_ioctl;
1323         dev->change_mtu = ip6_tnl_change_mtu;
1324
1325         dev->type = ARPHRD_TUNNEL6;
1326         dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr);
1327         dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr);
1328         dev->flags |= IFF_NOARP;
1329         dev->addr_len = sizeof(struct in6_addr);
1330 }
1331
1332
1333 /**
1334  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1335  *   @dev: virtual device associated with tunnel
1336  **/
1337
1338 static inline void
1339 ip6_tnl_dev_init_gen(struct net_device *dev)
1340 {
1341         struct ip6_tnl *t = netdev_priv(dev);
1342         t->dev = dev;
1343         strcpy(t->parms.name, dev->name);
1344 }
1345
1346 /**
1347  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1348  *   @dev: virtual device associated with tunnel
1349  **/
1350
1351 static int
1352 ip6_tnl_dev_init(struct net_device *dev)
1353 {
1354         struct ip6_tnl *t = netdev_priv(dev);
1355         ip6_tnl_dev_init_gen(dev);
1356         ip6_tnl_link_config(t);
1357         return 0;
1358 }
1359
1360 /**
1361  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1362  *   @dev: fallback device
1363  *
1364  * Return: 0
1365  **/
1366
1367 static int
1368 ip6_fb_tnl_dev_init(struct net_device *dev)
1369 {
1370         struct ip6_tnl *t = netdev_priv(dev);
1371         ip6_tnl_dev_init_gen(dev);
1372         t->parms.proto = IPPROTO_IPV6;
1373         dev_hold(dev);
1374         tnls_wc[0] = t;
1375         return 0;
1376 }
1377
1378 static struct xfrm6_tunnel ip4ip6_handler = {
1379         .handler        = ip4ip6_rcv,
1380         .err_handler    = ip4ip6_err,
1381         .priority       =       1,
1382 };
1383
1384 static struct xfrm6_tunnel ip6ip6_handler = {
1385         .handler        = ip6ip6_rcv,
1386         .err_handler    = ip6ip6_err,
1387         .priority       =       1,
1388 };
1389
1390 /**
1391  * ip6_tunnel_init - register protocol and reserve needed resources
1392  *
1393  * Return: 0 on success
1394  **/
1395
1396 static int __init ip6_tunnel_init(void)
1397 {
1398         int  err;
1399
1400         if (xfrm6_tunnel_register(&ip4ip6_handler, AF_INET)) {
1401                 printk(KERN_ERR "ip6_tunnel init: can't register ip4ip6\n");
1402                 err = -EAGAIN;
1403                 goto out;
1404         }
1405
1406         if (xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6)) {
1407                 printk(KERN_ERR "ip6_tunnel init: can't register ip6ip6\n");
1408                 err = -EAGAIN;
1409                 goto unreg_ip4ip6;
1410         }
1411         ip6_fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
1412                                       ip6_tnl_dev_setup);
1413
1414         if (!ip6_fb_tnl_dev) {
1415                 err = -ENOMEM;
1416                 goto fail;
1417         }
1418         ip6_fb_tnl_dev->init = ip6_fb_tnl_dev_init;
1419
1420         if ((err = register_netdev(ip6_fb_tnl_dev))) {
1421                 free_netdev(ip6_fb_tnl_dev);
1422                 goto fail;
1423         }
1424         return 0;
1425 fail:
1426         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
1427 unreg_ip4ip6:
1428         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
1429 out:
1430         return err;
1431 }
1432
1433 static void __exit ip6_tnl_destroy_tunnels(void)
1434 {
1435         int h;
1436         struct ip6_tnl *t;
1437
1438         for (h = 0; h < HASH_SIZE; h++) {
1439                 while ((t = tnls_r_l[h]) != NULL)
1440                         unregister_netdevice(t->dev);
1441         }
1442
1443         t = tnls_wc[0];
1444         unregister_netdevice(t->dev);
1445 }
1446
1447 /**
1448  * ip6_tunnel_cleanup - free resources and unregister protocol
1449  **/
1450
1451 static void __exit ip6_tunnel_cleanup(void)
1452 {
1453         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
1454                 printk(KERN_INFO "ip6_tunnel close: can't deregister ip4ip6\n");
1455
1456         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
1457                 printk(KERN_INFO "ip6_tunnel close: can't deregister ip6ip6\n");
1458
1459         rtnl_lock();
1460         ip6_tnl_destroy_tunnels();
1461         rtnl_unlock();
1462 }
1463
1464 module_init(ip6_tunnel_init);
1465 module_exit(ip6_tunnel_cleanup);