git.oblomov.eu Git - linux-2.6/blob - 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", __func__)
  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                 sprintf(name, "ip6tnl%%d");
 236
 237         dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup);
 238         if (dev == NULL)
 239                 goto failed;
 240
 241         if (strchr(name, '%')) {
 242                 if (dev_alloc_name(dev, name) < 0)
 243                         goto failed_free;
 244         }
 245
 246         t = netdev_priv(dev);
 247         dev->init = ip6_tnl_dev_init;
 248         t->parms = *p;
 249
 250         if ((err = register_netdevice(dev)) < 0)
 251                 goto failed_free;
 252
 253         dev_hold(dev);
 254         ip6_tnl_link(t);
 255         return t;
 256
 257 failed_free:
 258         free_netdev(dev);
 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, __u32 *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 == *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 = *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, __be32 info)
 482 {
 483         int rel_msg = 0;
 484         int rel_type = type;
 485         int rel_code = code;
 486         __u32 rel_info = ntohl(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(&init_net, &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(&init_net, &rt, &fl) ||
 549                     rt->u.dst.dev->type != ARPHRD_TUNNEL) {
 550                         ip_rt_put(rt);
 551                         goto out;
 552                 }
 553                 skb2->dst = (struct dst_entry *)rt;
 554         } else {
 555                 ip_rt_put(rt);
 556                 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos,
 557                                    skb2->dev) ||
 558                     skb2->dst->dev->type != ARPHRD_TUNNEL)
 559                         goto out;
 560         }
 561
 562         /* change mtu on this route */
 563         if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) {
 564                 if (rel_info > dst_mtu(skb2->dst))
 565                         goto out;
 566
 567                 skb2->dst->ops->update_pmtu(skb2->dst, rel_info);
 568         }
 569
 570         icmp_send(skb2, rel_type, rel_code, htonl(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, __be32 info)
 580 {
 581         int rel_msg = 0;
 582         int rel_type = type;
 583         int rel_code = code;
 584         __u32 rel_info = ntohl(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(&init_net, &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(ipv6_get_dsfield(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(&init_net, p->link);
 655
 656                 if ((ipv6_addr_is_multicast(&p->laddr) ||
 657                      likely(ipv6_chk_addr(&init_net, &p->laddr, ldev, 0))) &&
 658                     likely(!ipv6_chk_addr(&init_net, &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(&init_net, p->link);
 791
 792                 if (unlikely(!ipv6_chk_addr(&init_net, &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(&init_net, &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         unsigned 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(&init_net, 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->hop_limit = t->parms.hop_limit;
 915         ipv6h->nexthdr = proto;
 916         ipv6_addr_copy(&ipv6h->saddr, &fl->fl6_src);
 917         ipv6_addr_copy(&ipv6h->daddr, &fl->fl6_dst);
 918         nf_reset(skb);
 919         pkt_len = skb->len;
 920         err = ip6_local_out(skb);
 921
 922         if (net_xmit_eval(err) == 0) {
 923                 stats->tx_bytes += pkt_len;
 924                 stats->tx_packets++;
 925         } else {
 926                 stats->tx_errors++;
 927                 stats->tx_aborted_errors++;
 928         }
 929         ip6_tnl_dst_store(t, dst);
 930         return 0;
 931 tx_err_link_failure:
 932         stats->tx_carrier_errors++;
 933         dst_link_failure(skb);
 934 tx_err_dst_release:
 935         dst_release(dst);
 936         return err;
 937 }
 938
 939 static inline int
 940 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 941 {
 942         struct ip6_tnl *t = netdev_priv(dev);
 943         struct iphdr  *iph = ip_hdr(skb);
 944         int encap_limit = -1;
 945         struct flowi fl;
 946         __u8 dsfield;
 947         __u32 mtu;
 948         int err;
 949
 950         if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) ||
 951             !ip6_tnl_xmit_ctl(t))
 952                 return -1;
 953
 954         if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
 955                 encap_limit = t->parms.encap_limit;
 956
 957         memcpy(&fl, &t->fl, sizeof (fl));
 958         fl.proto = IPPROTO_IPIP;
 959
 960         dsfield = ipv4_get_dsfield(iph);
 961
 962         if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS))
 963                 fl.fl6_flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
 964                                           & IPV6_TCLASS_MASK;
 965
 966         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu);
 967         if (err != 0) {
 968                 /* XXX: send ICMP error even if DF is not set. */
 969                 if (err == -EMSGSIZE)
 970                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 971                                   htonl(mtu));
 972                 return -1;
 973         }
 974
 975         return 0;
 976 }
 977
 978 static inline int
 979 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 980 {
 981         struct ip6_tnl *t = netdev_priv(dev);
 982         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
 983         int encap_limit = -1;
 984         __u16 offset;
 985         struct flowi fl;
 986         __u8 dsfield;
 987         __u32 mtu;
 988         int err;
 989
 990         if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) ||
 991             !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h))
 992                 return -1;
 993
 994         offset = parse_tlv_tnl_enc_lim(skb, skb_network_header(skb));
 995         if (offset > 0) {
 996                 struct ipv6_tlv_tnl_enc_lim *tel;
 997                 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset];
 998                 if (tel->encap_limit == 0) {
 999                         icmpv6_send(skb, ICMPV6_PARAMPROB,
1000                                     ICMPV6_HDR_FIELD, offset + 2, skb->dev);
1001                         return -1;
1002                 }
1003                 encap_limit = tel->encap_limit - 1;
1004         } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT))
1005                 encap_limit = t->parms.encap_limit;
1006
1007         memcpy(&fl, &t->fl, sizeof (fl));
1008         fl.proto = IPPROTO_IPV6;
1009
1010         dsfield = ipv6_get_dsfield(ipv6h);
1011         if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS))
1012                 fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
1013         if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL))
1014                 fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK);
1015
1016         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu);
1017         if (err != 0) {
1018                 if (err == -EMSGSIZE)
1019                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev);
1020                 return -1;
1021         }
1022
1023         return 0;
1024 }
1025
1026 static int
1027 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
1028 {
1029         struct ip6_tnl *t = netdev_priv(dev);
1030         struct net_device_stats *stats = &t->stat;
1031         int ret;
1032
1033         if (t->recursion++) {
1034                 t->stat.collisions++;
1035                 goto tx_err;
1036         }
1037
1038         switch (skb->protocol) {
1039         case __constant_htons(ETH_P_IP):
1040                 ret = ip4ip6_tnl_xmit(skb, dev);
1041                 break;
1042         case __constant_htons(ETH_P_IPV6):
1043                 ret = ip6ip6_tnl_xmit(skb, dev);
1044                 break;
1045         default:
1046                 goto tx_err;
1047         }
1048
1049         if (ret < 0)
1050                 goto tx_err;
1051
1052         t->recursion--;
1053         return 0;
1054
1055 tx_err:
1056         stats->tx_errors++;
1057         stats->tx_dropped++;
1058         kfree_skb(skb);
1059         t->recursion--;
1060         return 0;
1061 }
1062
1063 static void ip6_tnl_set_cap(struct ip6_tnl *t)
1064 {
1065         struct ip6_tnl_parm *p = &t->parms;
1066         int ltype = ipv6_addr_type(&p->laddr);
1067         int rtype = ipv6_addr_type(&p->raddr);
1068
1069         p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV);
1070
1071         if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
1072             rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) &&
1073             !((ltype|rtype) & IPV6_ADDR_LOOPBACK) &&
1074             (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) {
1075                 if (ltype&IPV6_ADDR_UNICAST)
1076                         p->flags |= IP6_TNL_F_CAP_XMIT;
1077                 if (rtype&IPV6_ADDR_UNICAST)
1078                         p->flags |= IP6_TNL_F_CAP_RCV;
1079         }
1080 }
1081
1082 static void ip6_tnl_link_config(struct ip6_tnl *t)
1083 {
1084         struct net_device *dev = t->dev;
1085         struct ip6_tnl_parm *p = &t->parms;
1086         struct flowi *fl = &t->fl;
1087
1088         memcpy(&dev->dev_addr, &p->laddr, sizeof(struct in6_addr));
1089         memcpy(&dev->broadcast, &p->raddr, sizeof(struct in6_addr));
1090
1091         /* Set up flowi template */
1092         ipv6_addr_copy(&fl->fl6_src, &p->laddr);
1093         ipv6_addr_copy(&fl->fl6_dst, &p->raddr);
1094         fl->oif = p->link;
1095         fl->fl6_flowlabel = 0;
1096
1097         if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS))
1098                 fl->fl6_flowlabel |= IPV6_TCLASS_MASK & p->flowinfo;
1099         if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL))
1100                 fl->fl6_flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo;
1101
1102         ip6_tnl_set_cap(t);
1103
1104         if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV)
1105                 dev->flags |= IFF_POINTOPOINT;
1106         else
1107                 dev->flags &= ~IFF_POINTOPOINT;
1108
1109         dev->iflink = p->link;
1110
1111         if (p->flags & IP6_TNL_F_CAP_XMIT) {
1112                 int strict = (ipv6_addr_type(&p->raddr) &
1113                               (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL));
1114
1115                 struct rt6_info *rt = rt6_lookup(&init_net, &p->raddr, &p->laddr,
1116                                                  p->link, strict);
1117
1118                 if (rt == NULL)
1119                         return;
1120
1121                 if (rt->rt6i_dev) {
1122                         dev->hard_header_len = rt->rt6i_dev->hard_header_len +
1123                                 sizeof (struct ipv6hdr);
1124
1125                         dev->mtu = rt->rt6i_dev->mtu - sizeof (struct ipv6hdr);
1126
1127                         if (dev->mtu < IPV6_MIN_MTU)
1128                                 dev->mtu = IPV6_MIN_MTU;
1129                 }
1130                 dst_release(&rt->u.dst);
1131         }
1132 }
1133
1134 /**
1135  * ip6_tnl_change - update the tunnel parameters
1136  *   @t: tunnel to be changed
1137  *   @p: tunnel configuration parameters
1138  *   @active: != 0 if tunnel is ready for use
1139  *
1140  * Description:
1141  *   ip6_tnl_change() updates the tunnel parameters
1142  **/
1143
1144 static int
1145 ip6_tnl_change(struct ip6_tnl *t, struct ip6_tnl_parm *p)
1146 {
1147         ipv6_addr_copy(&t->parms.laddr, &p->laddr);
1148         ipv6_addr_copy(&t->parms.raddr, &p->raddr);
1149         t->parms.flags = p->flags;
1150         t->parms.hop_limit = p->hop_limit;
1151         t->parms.encap_limit = p->encap_limit;
1152         t->parms.flowinfo = p->flowinfo;
1153         t->parms.link = p->link;
1154         t->parms.proto = p->proto;
1155         ip6_tnl_dst_reset(t);
1156         ip6_tnl_link_config(t);
1157         return 0;
1158 }
1159
1160 /**
1161  * ip6_tnl_ioctl - configure ipv6 tunnels from userspace
1162  *   @dev: virtual device associated with tunnel
1163  *   @ifr: parameters passed from userspace
1164  *   @cmd: command to be performed
1165  *
1166  * Description:
1167  *   ip6_tnl_ioctl() is used for managing IPv6 tunnels
1168  *   from userspace.
1169  *
1170  *   The possible commands are the following:
1171  *     %SIOCGETTUNNEL: get tunnel parameters for device
1172  *     %SIOCADDTUNNEL: add tunnel matching given tunnel parameters
1173  *     %SIOCCHGTUNNEL: change tunnel parameters to those given
1174  *     %SIOCDELTUNNEL: delete tunnel
1175  *
1176  *   The fallback device "ip6tnl0", created during module
1177  *   initialization, can be used for creating other tunnel devices.
1178  *
1179  * Return:
1180  *   0 on success,
1181  *   %-EFAULT if unable to copy data to or from userspace,
1182  *   %-EPERM if current process hasn't %CAP_NET_ADMIN set
1183  *   %-EINVAL if passed tunnel parameters are invalid,
1184  *   %-EEXIST if changing a tunnel's parameters would cause a conflict
1185  *   %-ENODEV if attempting to change or delete a nonexisting device
1186  **/
1187
1188 static int
1189 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
1190 {
1191         int err = 0;
1192         struct ip6_tnl_parm p;
1193         struct ip6_tnl *t = NULL;
1194
1195         switch (cmd) {
1196         case SIOCGETTUNNEL:
1197                 if (dev == ip6_fb_tnl_dev) {
1198                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) {
1199                                 err = -EFAULT;
1200                                 break;
1201                         }
1202                         t = ip6_tnl_locate(&p, 0);
1203                 }
1204                 if (t == NULL)
1205                         t = netdev_priv(dev);
1206                 memcpy(&p, &t->parms, sizeof (p));
1207                 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) {
1208                         err = -EFAULT;
1209                 }
1210                 break;
1211         case SIOCADDTUNNEL:
1212         case SIOCCHGTUNNEL:
1213                 err = -EPERM;
1214                 if (!capable(CAP_NET_ADMIN))
1215                         break;
1216                 err = -EFAULT;
1217                 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1218                         break;
1219                 err = -EINVAL;
1220                 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP &&
1221                     p.proto != 0)
1222                         break;
1223                 t = ip6_tnl_locate(&p, cmd == SIOCADDTUNNEL);
1224                 if (dev != ip6_fb_tnl_dev && cmd == SIOCCHGTUNNEL) {
1225                         if (t != NULL) {
1226                                 if (t->dev != dev) {
1227                                         err = -EEXIST;
1228                                         break;
1229                                 }
1230                         } else
1231                                 t = netdev_priv(dev);
1232
1233                         ip6_tnl_unlink(t);
1234                         err = ip6_tnl_change(t, &p);
1235                         ip6_tnl_link(t);
1236                         netdev_state_change(dev);
1237                 }
1238                 if (t) {
1239                         err = 0;
1240                         if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof (p)))
1241                                 err = -EFAULT;
1242
1243                 } else
1244                         err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
1245                 break;
1246         case SIOCDELTUNNEL:
1247                 err = -EPERM;
1248                 if (!capable(CAP_NET_ADMIN))
1249                         break;
1250
1251                 if (dev == ip6_fb_tnl_dev) {
1252                         err = -EFAULT;
1253                         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p)))
1254                                 break;
1255                         err = -ENOENT;
1256                         if ((t = ip6_tnl_locate(&p, 0)) == NULL)
1257                                 break;
1258                         err = -EPERM;
1259                         if (t->dev == ip6_fb_tnl_dev)
1260                                 break;
1261                         dev = t->dev;
1262                 }
1263                 err = 0;
1264                 unregister_netdevice(dev);
1265                 break;
1266         default:
1267                 err = -EINVAL;
1268         }
1269         return err;
1270 }
1271
1272 /**
1273  * ip6_tnl_get_stats - return the stats for tunnel device
1274  *   @dev: virtual device associated with tunnel
1275  *
1276  * Return: stats for device
1277  **/
1278
1279 static struct net_device_stats *
1280 ip6_tnl_get_stats(struct net_device *dev)
1281 {
1282         return &(((struct ip6_tnl *)netdev_priv(dev))->stat);
1283 }
1284
1285 /**
1286  * ip6_tnl_change_mtu - change mtu manually for tunnel device
1287  *   @dev: virtual device associated with tunnel
1288  *   @new_mtu: the new mtu
1289  *
1290  * Return:
1291  *   0 on success,
1292  *   %-EINVAL if mtu too small
1293  **/
1294
1295 static int
1296 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu)
1297 {
1298         if (new_mtu < IPV6_MIN_MTU) {
1299                 return -EINVAL;
1300         }
1301         dev->mtu = new_mtu;
1302         return 0;
1303 }
1304
1305 /**
1306  * ip6_tnl_dev_setup - setup virtual tunnel device
1307  *   @dev: virtual device associated with tunnel
1308  *
1309  * Description:
1310  *   Initialize function pointers and device parameters
1311  **/
1312
1313 static void ip6_tnl_dev_setup(struct net_device *dev)
1314 {
1315         dev->uninit = ip6_tnl_dev_uninit;
1316         dev->destructor = free_netdev;
1317         dev->hard_start_xmit = ip6_tnl_xmit;
1318         dev->get_stats = ip6_tnl_get_stats;
1319         dev->do_ioctl = ip6_tnl_ioctl;
1320         dev->change_mtu = ip6_tnl_change_mtu;
1321
1322         dev->type = ARPHRD_TUNNEL6;
1323         dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr);
1324         dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr);
1325         dev->flags |= IFF_NOARP;
1326         dev->addr_len = sizeof(struct in6_addr);
1327 }
1328
1329
1330 /**
1331  * ip6_tnl_dev_init_gen - general initializer for all tunnel devices
1332  *   @dev: virtual device associated with tunnel
1333  **/
1334
1335 static inline void
1336 ip6_tnl_dev_init_gen(struct net_device *dev)
1337 {
1338         struct ip6_tnl *t = netdev_priv(dev);
1339         t->dev = dev;
1340         strcpy(t->parms.name, dev->name);
1341 }
1342
1343 /**
1344  * ip6_tnl_dev_init - initializer for all non fallback tunnel devices
1345  *   @dev: virtual device associated with tunnel
1346  **/
1347
1348 static int
1349 ip6_tnl_dev_init(struct net_device *dev)
1350 {
1351         struct ip6_tnl *t = netdev_priv(dev);
1352         ip6_tnl_dev_init_gen(dev);
1353         ip6_tnl_link_config(t);
1354         return 0;
1355 }
1356
1357 /**
1358  * ip6_fb_tnl_dev_init - initializer for fallback tunnel device
1359  *   @dev: fallback device
1360  *
1361  * Return: 0
1362  **/
1363
1364 static int
1365 ip6_fb_tnl_dev_init(struct net_device *dev)
1366 {
1367         struct ip6_tnl *t = netdev_priv(dev);
1368         ip6_tnl_dev_init_gen(dev);
1369         t->parms.proto = IPPROTO_IPV6;
1370         dev_hold(dev);
1371         tnls_wc[0] = t;
1372         return 0;
1373 }
1374
1375 static struct xfrm6_tunnel ip4ip6_handler = {
1376         .handler        = ip4ip6_rcv,
1377         .err_handler    = ip4ip6_err,
1378         .priority       =       1,
1379 };
1380
1381 static struct xfrm6_tunnel ip6ip6_handler = {
1382         .handler        = ip6ip6_rcv,
1383         .err_handler    = ip6ip6_err,
1384         .priority       =       1,
1385 };
1386
1387 /**
1388  * ip6_tunnel_init - register protocol and reserve needed resources
1389  *
1390  * Return: 0 on success
1391  **/
1392
1393 static int __init ip6_tunnel_init(void)
1394 {
1395         int  err;
1396
1397         if (xfrm6_tunnel_register(&ip4ip6_handler, AF_INET)) {
1398                 printk(KERN_ERR "ip6_tunnel init: can't register ip4ip6\n");
1399                 err = -EAGAIN;
1400                 goto out;
1401         }
1402
1403         if (xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6)) {
1404                 printk(KERN_ERR "ip6_tunnel init: can't register ip6ip6\n");
1405                 err = -EAGAIN;
1406                 goto unreg_ip4ip6;
1407         }
1408         ip6_fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0",
1409                                       ip6_tnl_dev_setup);
1410
1411         if (!ip6_fb_tnl_dev) {
1412                 err = -ENOMEM;
1413                 goto fail;
1414         }
1415         ip6_fb_tnl_dev->init = ip6_fb_tnl_dev_init;
1416
1417         if ((err = register_netdev(ip6_fb_tnl_dev))) {
1418                 free_netdev(ip6_fb_tnl_dev);
1419                 goto fail;
1420         }
1421         return 0;
1422 fail:
1423         xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6);
1424 unreg_ip4ip6:
1425         xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET);
1426 out:
1427         return err;
1428 }
1429
1430 static void __exit ip6_tnl_destroy_tunnels(void)
1431 {
1432         int h;
1433         struct ip6_tnl *t;
1434
1435         for (h = 0; h < HASH_SIZE; h++) {
1436                 while ((t = tnls_r_l[h]) != NULL)
1437                         unregister_netdevice(t->dev);
1438         }
1439
1440         t = tnls_wc[0];
1441         unregister_netdevice(t->dev);
1442 }
1443
1444 /**
1445  * ip6_tunnel_cleanup - free resources and unregister protocol
1446  **/
1447
1448 static void __exit ip6_tunnel_cleanup(void)
1449 {
1450         if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET))
1451                 printk(KERN_INFO "ip6_tunnel close: can't deregister ip4ip6\n");
1452
1453         if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6))
1454                 printk(KERN_INFO "ip6_tunnel close: can't deregister ip6ip6\n");
1455
1456         rtnl_lock();
1457         ip6_tnl_destroy_tunnels();
1458         rtnl_unlock();
1459 }
1460
1461 module_init(ip6_tunnel_init);
1462 module_exit(ip6_tunnel_cleanup);