net/ipv6/netfilter/ip6_queue.c

   1 /*
   2  * This is a module which is used for queueing IPv6 packets and
   3  * communicating with userspace via netlink.
   4  *
   5  * (C) 2001 Fernando Anton, this code is GPL.
   6  *     IPv64 Project - Work based in IPv64 draft by Arturo Azcorra.
   7  *     Universidad Carlos III de Madrid - Leganes (Madrid) - Spain
   8  *     Universidad Politecnica de Alcala de Henares - Alcala de H. (Madrid) - Spain
   9  *     email: fanton@it.uc3m.es
  10  *
  11  * 2001-11-06: First try. Working with ip_queue.c for IPv4 and trying
  12  *             to adapt it to IPv6
  13  *             HEAVILY based in ipqueue.c by James Morris. It's just
  14  *             a little modified version of it, so he's nearly the
  15  *             real coder of this.
  16  *             Few changes needed, mainly the hard_routing code and
  17  *             the netlink socket protocol (we're NETLINK_IP6_FW).
  18  * 2002-06-25: Code cleanup. [JM: ported cleanup over from ip_queue.c]
  19  */
  20 #include <linux/module.h>
  21 #include <linux/skbuff.h>
  22 #include <linux/init.h>
  23 #include <linux/ipv6.h>
  24 #include <linux/notifier.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/netfilter.h>
  27 #include <linux/netlink.h>
  28 #include <linux/spinlock.h>
  29 #include <linux/brlock.h>
  30 #include <linux/sysctl.h>
  31 #include <linux/proc_fs.h>
  32 #include <net/sock.h>
  33 #include <net/ipv6.h>
  34 #include <net/ip6_route.h>
  35 #include <linux/netfilter_ipv4/ip_queue.h>
  36 #include <linux/netfilter_ipv4/ip_tables.h>
  37 #include <linux/netfilter_ipv6/ip6_tables.h>
  38
  39 #define IPQ_QMAX_DEFAULT 1024
  40 #define IPQ_PROC_FS_NAME "ip6_queue"
  41 #define NET_IPQ_QMAX 2088
  42 #define NET_IPQ_QMAX_NAME "ip6_queue_maxlen"
  43
  44 struct ipq_rt_info {
  45         struct in6_addr daddr;
  46         struct in6_addr saddr;
  47 };
  48
  49 struct ipq_queue_entry {
  50         struct list_head list;
  51         struct nf_info *info;
  52         struct sk_buff *skb;
  53         struct ipq_rt_info rt_info;
  54 };
  55
  56 typedef int (*ipq_cmpfn)(struct ipq_queue_entry *, unsigned long);
  57
  58 static unsigned char copy_mode = IPQ_COPY_NONE;
  59 static unsigned int queue_maxlen = IPQ_QMAX_DEFAULT;
  60 static rwlock_t queue_lock = RW_LOCK_UNLOCKED;
  61 static int peer_pid;
  62 static unsigned int copy_range;
  63 static unsigned int queue_total;
  64 static struct sock *ipqnl;
  65 static LIST_HEAD(queue_list);
  66 static DECLARE_MUTEX(ipqnl_sem);
  67
  68 static void
  69 ipq_issue_verdict(struct ipq_queue_entry *entry, int verdict)
  70 {
  71         local_bh_disable();
  72         nf_reinject(entry->skb, entry->info, verdict);
  73         local_bh_enable();
  74         kfree(entry);
  75 }
  76
  77 static inline int
  78 __ipq_enqueue_entry(struct ipq_queue_entry *entry)
  79 {
  80        if (queue_total >= queue_maxlen) {
  81                if (net_ratelimit())
  82                        printk(KERN_WARNING "ip6_queue: full at %d entries, "
  83                               "dropping packet(s).\n", queue_total);
  84                return -ENOSPC;
  85        }
  86        list_add(&entry->list, &queue_list);
  87        queue_total++;
  88        return 0;
  89 }
  90
  91 /*
  92  * Find and return a queued entry matched by cmpfn, or return the last
  93  * entry if cmpfn is NULL.
  94  */
  95 static inline struct ipq_queue_entry *
  96 __ipq_find_entry(ipq_cmpfn cmpfn, unsigned long data)
  97 {
  98         struct list_head *p;
  99
 100         list_for_each_prev(p, &queue_list) {
 101                 struct ipq_queue_entry *entry = (struct ipq_queue_entry *)p;
 102
 103                 if (!cmpfn || cmpfn(entry, data))
 104                         return entry;
 105         }
 106         return NULL;
 107 }
 108
 109 static inline void
 110 __ipq_dequeue_entry(struct ipq_queue_entry *entry)
 111 {
 112         list_del(&entry->list);
 113         queue_total--;
 114 }
 115
 116 static inline struct ipq_queue_entry *
 117 __ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 118 {
 119         struct ipq_queue_entry *entry;
 120
 121         entry = __ipq_find_entry(cmpfn, data);
 122         if (entry == NULL)
 123                 return NULL;
 124
 125         __ipq_dequeue_entry(entry);
 126         return entry;
 127 }
 128
 129
 130 static inline void
 131 __ipq_flush(int verdict)
 132 {
 133         struct ipq_queue_entry *entry;
 134
 135         while ((entry = __ipq_find_dequeue_entry(NULL, 0)))
 136                 ipq_issue_verdict(entry, verdict);
 137 }
 138
 139 static inline int
 140 __ipq_set_mode(unsigned char mode, unsigned int range)
 141 {
 142         int status = 0;
 143
 144         switch(mode) {
 145         case IPQ_COPY_NONE:
 146         case IPQ_COPY_META:
 147                 copy_mode = mode;
 148                 copy_range = 0;
 149                 break;
 150
 151         case IPQ_COPY_PACKET:
 152                 copy_mode = mode;
 153                 copy_range = range;
 154                 if (copy_range > 0xFFFF)
 155                         copy_range = 0xFFFF;
 156                 break;
 157
 158         default:
 159                 status = -EINVAL;
 160
 161         }
 162         return status;
 163 }
 164
 165 static inline void
 166 __ipq_reset(void)
 167 {
 168         peer_pid = 0;
 169         __ipq_set_mode(IPQ_COPY_NONE, 0);
 170         __ipq_flush(NF_DROP);
 171 }
 172
 173 static struct ipq_queue_entry *
 174 ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 175 {
 176         struct ipq_queue_entry *entry;
 177
 178         write_lock_bh(&queue_lock);
 179         entry = __ipq_find_dequeue_entry(cmpfn, data);
 180         write_unlock_bh(&queue_lock);
 181         return entry;
 182 }
 183
 184 static void
 185 ipq_flush(int verdict)
 186 {
 187         write_lock_bh(&queue_lock);
 188         __ipq_flush(verdict);
 189         write_unlock_bh(&queue_lock);
 190 }
 191
 192 static struct sk_buff *
 193 ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 194 {
 195         unsigned char *old_tail;
 196         size_t size = 0;
 197         size_t data_len = 0;
 198         struct sk_buff *skb;
 199         struct ipq_packet_msg *pmsg;
 200         struct nlmsghdr *nlh;
 201
 202         read_lock_bh(&queue_lock);
 203
 204         switch (copy_mode) {
 205         case IPQ_COPY_META:
 206         case IPQ_COPY_NONE:
 207                 size = NLMSG_SPACE(sizeof(*pmsg));
 208                 data_len = 0;
 209                 break;
 210
 211         case IPQ_COPY_PACKET:
 212                 if (copy_range == 0 || copy_range > entry->skb->len)
 213                         data_len = entry->skb->len;
 214                 else
 215                         data_len = copy_range;
 216
 217                 size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
 218                 break;
 219
 220         default:
 221                 *errp = -EINVAL;
 222                 read_unlock_bh(&queue_lock);
 223                 return NULL;
 224         }
 225
 226         read_unlock_bh(&queue_lock);
 227
 228         skb = alloc_skb(size, GFP_ATOMIC);
 229         if (!skb)
 230                 goto nlmsg_failure;
 231
 232         old_tail= skb->tail;
 233         nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
 234         pmsg = NLMSG_DATA(nlh);
 235         memset(pmsg, 0, sizeof(*pmsg));
 236
 237         pmsg->packet_id       = (unsigned long )entry;
 238         pmsg->data_len        = data_len;
 239         pmsg->timestamp_sec   = entry->skb->stamp.tv_sec;
 240         pmsg->timestamp_usec  = entry->skb->stamp.tv_usec;
 241         pmsg->mark            = entry->skb->nfmark;
 242         pmsg->hook            = entry->info->hook;
 243         pmsg->hw_protocol     = entry->skb->protocol;
 244
 245         if (entry->info->indev)
 246                 strcpy(pmsg->indev_name, entry->info->indev->name);
 247         else
 248                 pmsg->indev_name[0] = '\0';
 249
 250         if (entry->info->outdev)
 251                 strcpy(pmsg->outdev_name, entry->info->outdev->name);
 252         else
 253                 pmsg->outdev_name[0] = '\0';
 254
 255         if (entry->info->indev && entry->skb->dev) {
 256                 pmsg->hw_type = entry->skb->dev->type;
 257                 if (entry->skb->dev->hard_header_parse)
 258                         pmsg->hw_addrlen =
 259                                 entry->skb->dev->hard_header_parse(entry->skb,
 260                                                                    pmsg->hw_addr);
 261         }
 262
 263         if (data_len)
 264                 memcpy(pmsg->payload, entry->skb->data, data_len);
 265
 266         nlh->nlmsg_len = skb->tail - old_tail;
 267         return skb;
 268
 269 nlmsg_failure:
 270         if (skb)
 271                 kfree_skb(skb);
 272         *errp = -EINVAL;
 273         printk(KERN_ERR "ip6_queue: error creating packet message\n");
 274         return NULL;
 275 }
 276
 277 static int
 278 ipq_enqueue_packet(struct sk_buff *skb, struct nf_info *info, void *data)
 279 {
 280         int status = -EINVAL;
 281         struct sk_buff *nskb;
 282         struct ipq_queue_entry *entry;
 283
 284         if (copy_mode == IPQ_COPY_NONE)
 285                 return -EAGAIN;
 286
 287         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 288         if (entry == NULL) {
 289                 printk(KERN_ERR "ip6_queue: OOM in ipq_enqueue_packet()\n");
 290                 return -ENOMEM;
 291         }
 292
 293         entry->info = info;
 294         entry->skb = skb;
 295
 296         if (entry->info->hook == NF_IP_LOCAL_OUT) {
 297                 struct ipv6hdr *iph = skb->nh.ipv6h;
 298
 299                 entry->rt_info.daddr = iph->daddr;
 300                 entry->rt_info.saddr = iph->saddr;
 301         }
 302
 303         nskb = ipq_build_packet_message(entry, &status);
 304         if (nskb == NULL)
 305                 goto err_out_free;
 306
 307         write_lock_bh(&queue_lock);
 308
 309         if (!peer_pid)
 310                 goto err_out_free_nskb;
 311
 312         /* netlink_unicast will either free the nskb or attach it to a socket */
 313         status = netlink_unicast(ipqnl, nskb, peer_pid, MSG_DONTWAIT);
 314         if (status < 0)
 315                 goto err_out_unlock;
 316
 317         status = __ipq_enqueue_entry(entry);
 318         if (status < 0)
 319                 goto err_out_unlock;
 320
 321         write_unlock_bh(&queue_lock);
 322         return status;
 323
 324 err_out_free_nskb:
 325         kfree_skb(nskb);
 326
 327 err_out_unlock:
 328         write_unlock_bh(&queue_lock);
 329
 330 err_out_free:
 331         kfree(entry);
 332         return status;
 333 }
 334
 335 static int
 336 ipq_mangle_ipv6(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
 337 {
 338         int diff;
 339         struct ipv6hdr *user_iph = (struct ipv6hdr *)v->payload;
 340
 341         if (v->data_len < sizeof(*user_iph))
 342                 return 0;
 343         diff = v->data_len - e->skb->len;
 344         if (diff < 0)
 345                 skb_trim(e->skb, v->data_len);
 346         else if (diff > 0) {
 347                 if (v->data_len > 0xFFFF)
 348                         return -EINVAL;
 349                 if (diff > skb_tailroom(e->skb)) {
 350                         struct sk_buff *newskb;
 351
 352                         newskb = skb_copy_expand(e->skb,
 353                                                  skb_headroom(e->skb),
 354                                                  diff,
 355                                                  GFP_ATOMIC);
 356                         if (newskb == NULL) {
 357                                 printk(KERN_WARNING "ip6_queue: OOM "
 358                                       "in mangle, dropping packet\n");
 359                                 return -ENOMEM;
 360                         }
 361                         if (e->skb->sk)
 362                                 skb_set_owner_w(newskb, e->skb->sk);
 363                         kfree_skb(e->skb);
 364                         e->skb = newskb;
 365                 }
 366                 skb_put(e->skb, diff);
 367         }
 368         memcpy(e->skb->data, v->payload, v->data_len);
 369         e->skb->nfcache |= NFC_ALTERED;
 370
 371         /*
 372          * Extra routing may needed on local out, as the QUEUE target never
 373          * returns control to the table.
 374          * Not a nice way to cmp, but works
 375          */
 376         if (e->info->hook == NF_IP_LOCAL_OUT) {
 377                 struct ipv6hdr *iph = e->skb->nh.ipv6h;
 378                 if (ipv6_addr_cmp(&iph->daddr, &e->rt_info.daddr) ||
 379                     ipv6_addr_cmp(&iph->saddr, &e->rt_info.saddr))
 380                         return ip6_route_me_harder(e->skb);
 381         }
 382         return 0;
 383 }
 384
 385 static inline int
 386 id_cmp(struct ipq_queue_entry *e, unsigned long id)
 387 {
 388         return (id == (unsigned long )e);
 389 }
 390
 391 static int
 392 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
 393 {
 394         struct ipq_queue_entry *entry;
 395
 396         if (vmsg->value > NF_MAX_VERDICT)
 397                 return -EINVAL;
 398
 399         entry = ipq_find_dequeue_entry(id_cmp, vmsg->id);
 400         if (entry == NULL)
 401                 return -ENOENT;
 402         else {
 403                 int verdict = vmsg->value;
 404
 405                 if (vmsg->data_len && vmsg->data_len == len)
 406                         if (ipq_mangle_ipv6(vmsg, entry) < 0)
 407                                 verdict = NF_DROP;
 408
 409                 ipq_issue_verdict(entry, verdict);
 410                 return 0;
 411         }
 412 }
 413
 414 static int
 415 ipq_set_mode(unsigned char mode, unsigned int range)
 416 {
 417         int status;
 418
 419         write_lock_bh(&queue_lock);
 420         status = __ipq_set_mode(mode, range);
 421         write_unlock_bh(&queue_lock);
 422         return status;
 423 }
 424
 425 static int
 426 ipq_receive_peer(struct ipq_peer_msg *pmsg,
 427                  unsigned char type, unsigned int len)
 428 {
 429         int status = 0;
 430
 431         if (len < sizeof(*pmsg))
 432                 return -EINVAL;
 433
 434         switch (type) {
 435         case IPQM_MODE:
 436                 status = ipq_set_mode(pmsg->msg.mode.value,
 437                                       pmsg->msg.mode.range);
 438                 break;
 439
 440         case IPQM_VERDICT:
 441                 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
 442                         status = -EINVAL;
 443                 else
 444                         status = ipq_set_verdict(&pmsg->msg.verdict,
 445                                                  len - sizeof(*pmsg));
 446                         break;
 447         default:
 448                 status = -EINVAL;
 449         }
 450         return status;
 451 }
 452
 453 static int
 454 dev_cmp(struct ipq_queue_entry *entry, unsigned long ifindex)
 455 {
 456         if (entry->info->indev)
 457                 if (entry->info->indev->ifindex == ifindex)
 458                         return 1;
 459
 460         if (entry->info->outdev)
 461                 if (entry->info->outdev->ifindex == ifindex)
 462                         return 1;
 463
 464         return 0;
 465 }
 466
 467 static void
 468 ipq_dev_drop(int ifindex)
 469 {
 470         struct ipq_queue_entry *entry;
 471
 472         while ((entry = ipq_find_dequeue_entry(dev_cmp, ifindex)) != NULL)
 473                 ipq_issue_verdict(entry, NF_DROP);
 474 }
 475
 476 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 477
 478 static inline void
 479 ipq_rcv_skb(struct sk_buff *skb)
 480 {
 481         int status, type, pid, flags, nlmsglen, skblen;
 482         struct nlmsghdr *nlh;
 483
 484         skblen = skb->len;
 485         if (skblen < sizeof(*nlh))
 486                 return;
 487
 488         nlh = (struct nlmsghdr *)skb->data;
 489         nlmsglen = nlh->nlmsg_len;
 490         if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
 491                 return;
 492
 493         pid = nlh->nlmsg_pid;
 494         flags = nlh->nlmsg_flags;
 495
 496         if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
 497                 RCV_SKB_FAIL(-EINVAL);
 498
 499         if (flags & MSG_TRUNC)
 500                 RCV_SKB_FAIL(-ECOMM);
 501
 502         type = nlh->nlmsg_type;
 503         if (type < NLMSG_NOOP || type >= IPQM_MAX)
 504                 RCV_SKB_FAIL(-EINVAL);
 505
 506         if (type <= IPQM_BASE)
 507                 return;
 508
 509         if(!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN))
 510                 RCV_SKB_FAIL(-EPERM);
 511
 512         write_lock_bh(&queue_lock);
 513
 514         if (peer_pid) {
 515                 if (peer_pid != pid) {
 516                         write_unlock_bh(&queue_lock);
 517                         RCV_SKB_FAIL(-EBUSY);
 518                 }
 519         }
 520         else
 521                 peer_pid = pid;
 522
 523         write_unlock_bh(&queue_lock);
 524
 525         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 526                                   nlmsglen - NLMSG_LENGTH(0));
 527         if (status < 0)
 528                 RCV_SKB_FAIL(status);
 529
 530         if (flags & NLM_F_ACK)
 531                 netlink_ack(skb, nlh, 0);
 532         return;
 533 }
 534
 535 static void
 536 ipq_rcv_sk(struct sock *sk, int len)
 537 {
 538         do {
 539                 struct sk_buff *skb;
 540
 541                 if (down_trylock(&ipqnl_sem))
 542                         return;
 543
 544                 while ((skb = skb_dequeue(&sk->receive_queue)) != NULL) {
 545                         ipq_rcv_skb(skb);
 546                         kfree_skb(skb);
 547                 }
 548
 549                 up(&ipqnl_sem);
 550
 551         } while (ipqnl && ipqnl->receive_queue.qlen);
 552 }
 553
 554 static int
 555 ipq_rcv_dev_event(struct notifier_block *this,
 556                   unsigned long event, void *ptr)
 557 {
 558         struct net_device *dev = ptr;
 559
 560         /* Drop any packets associated with the downed device */
 561         if (event == NETDEV_DOWN)
 562                 ipq_dev_drop(dev->ifindex);
 563         return NOTIFY_DONE;
 564 }
 565
 566 static struct notifier_block ipq_dev_notifier = {
 567         ipq_rcv_dev_event,
 568         NULL,
 569         0
 570 };
 571
 572 static int
 573 ipq_rcv_nl_event(struct notifier_block *this,
 574                  unsigned long event, void *ptr)
 575 {
 576         struct netlink_notify *n = ptr;
 577
 578         if (event == NETLINK_URELEASE &&
 579             n->protocol == NETLINK_IP6_FW && n->pid) {
 580                 write_lock_bh(&queue_lock);
 581                 if (n->pid == peer_pid)
 582                         __ipq_reset();
 583                 write_unlock_bh(&queue_lock);
 584         }
 585         return NOTIFY_DONE;
 586 }
 587
 588 static struct notifier_block ipq_nl_notifier = {
 589         ipq_rcv_nl_event,
 590         NULL,
 591         0
 592 };
 593
 594 static struct ctl_table_header *ipq_sysctl_header;
 595
 596 static ctl_table ipq_table[] = {
 597         { NET_IPQ_QMAX, NET_IPQ_QMAX_NAME, &queue_maxlen,
 598           sizeof(queue_maxlen), 0644,  NULL, proc_dointvec },
 599         { 0 }
 600 };
 601
 602 static ctl_table ipq_dir_table[] = {
 603         {NET_IPV6, "ipv6", NULL, 0, 0555, ipq_table, 0, 0, 0, 0, 0},
 604         { 0 }
 605 };
 606
 607 static ctl_table ipq_root_table[] = {
 608         {CTL_NET, "net", NULL, 0, 0555, ipq_dir_table, 0, 0, 0, 0, 0},
 609         { 0 }
 610 };
 611
 612 static int
 613 ipq_get_info(char *buffer, char **start, off_t offset, int length)
 614 {
 615         int len;
 616
 617         read_lock_bh(&queue_lock);
 618
 619         len = sprintf(buffer,
 620                       "Peer PID          : %d\n"
 621                       "Copy mode         : %hu\n"
 622                       "Copy range        : %u\n"
 623                       "Queue length      : %u\n"
 624                       "Queue max. length : %u\n",
 625                       peer_pid,
 626                       copy_mode,
 627                       copy_range,
 628                       queue_total,
 629                       queue_maxlen);
 630
 631         read_unlock_bh(&queue_lock);
 632
 633         *start = buffer + offset;
 634         len -= offset;
 635         if (len > length)
 636                 len = length;
 637         else if (len < 0)
 638                 len = 0;
 639         return len;
 640 }
 641
 642 static int
 643 init_or_cleanup(int init)
 644 {
 645         int status = -ENOMEM;
 646         struct proc_dir_entry *proc;
 647
 648         if (!init)
 649                 goto cleanup;
 650
 651         netlink_register_notifier(&ipq_nl_notifier);
 652         ipqnl = netlink_kernel_create(NETLINK_IP6_FW, ipq_rcv_sk);
 653         if (ipqnl == NULL) {
 654                 printk(KERN_ERR "ip6_queue: failed to create netlink socket\n");
 655                 goto cleanup_netlink_notifier;
 656         }
 657
 658         proc = proc_net_create(IPQ_PROC_FS_NAME, 0, ipq_get_info);
 659         if (proc)
 660                 proc->owner = THIS_MODULE;
 661         else {
 662                 printk(KERN_ERR "ip6_queue: failed to create proc entry\n");
 663                 goto cleanup_ipqnl;
 664         }
 665
 666         register_netdevice_notifier(&ipq_dev_notifier);
 667         ipq_sysctl_header = register_sysctl_table(ipq_root_table, 0);
 668
 669         status = nf_register_queue_handler(PF_INET6, ipq_enqueue_packet, NULL);
 670         if (status < 0) {
 671                 printk(KERN_ERR "ip6_queue: failed to register queue handler\n");
 672                 goto cleanup_sysctl;
 673         }
 674         return status;
 675
 676 cleanup:
 677         nf_unregister_queue_handler(PF_INET6);
 678         br_write_lock_bh(BR_NETPROTO_LOCK);
 679         br_write_unlock_bh(BR_NETPROTO_LOCK);
 680         ipq_flush(NF_DROP);
 681
 682 cleanup_sysctl:
 683         unregister_sysctl_table(ipq_sysctl_header);
 684         unregister_netdevice_notifier(&ipq_dev_notifier);
 685         proc_net_remove(IPQ_PROC_FS_NAME);
 686
 687 cleanup_ipqnl:
 688         sock_release(ipqnl->socket);
 689         down(&ipqnl_sem);
 690         up(&ipqnl_sem);
 691
 692 cleanup_netlink_notifier:
 693         netlink_unregister_notifier(&ipq_nl_notifier);
 694         return status;
 695 }
 696
 697 static int __init init(void)
 698 {
 699
 700         return init_or_cleanup(1);
 701 }
 702
 703 static void __exit fini(void)
 704 {
 705         init_or_cleanup(0);
 706 }
 707
 708 MODULE_DESCRIPTION("IPv6 packet queue handler");
 709 MODULE_LICENSE("GPL");
 710
 711 module_init(init);
 712 module_exit(fini);