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  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  */
  15 #include <linux/module.h>
  16 #include <linux/skbuff.h>
  17 #include <linux/init.h>
  18 #include <linux/ipv6.h>
  19 #include <linux/notifier.h>
  20 #include <linux/netdevice.h>
  21 #include <linux/netfilter.h>
  22 #include <linux/netlink.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/sysctl.h>
  25 #include <linux/proc_fs.h>
  26 #include <linux/mutex.h>
  27 #include <net/net_namespace.h>
  28 #include <net/sock.h>
  29 #include <net/ipv6.h>
  30 #include <net/ip6_route.h>
  31 #include <linux/netfilter_ipv4/ip_queue.h>
  32 #include <linux/netfilter_ipv4/ip_tables.h>
  33 #include <linux/netfilter_ipv6/ip6_tables.h>
  34
  35 #define IPQ_QMAX_DEFAULT 1024
  36 #define IPQ_PROC_FS_NAME "ip6_queue"
  37 #define NET_IPQ_QMAX 2088
  38 #define NET_IPQ_QMAX_NAME "ip6_queue_maxlen"
  39
  40 struct ipq_queue_entry {
  41         struct list_head list;
  42         struct nf_info *info;
  43         struct sk_buff *skb;
  44 };
  45
  46 typedef int (*ipq_cmpfn)(struct ipq_queue_entry *, unsigned long);
  47
  48 static unsigned char copy_mode __read_mostly = IPQ_COPY_NONE;
  49 static unsigned int queue_maxlen __read_mostly = IPQ_QMAX_DEFAULT;
  50 static DEFINE_RWLOCK(queue_lock);
  51 static int peer_pid __read_mostly;
  52 static unsigned int copy_range __read_mostly;
  53 static unsigned int queue_total;
  54 static unsigned int queue_dropped = 0;
  55 static unsigned int queue_user_dropped = 0;
  56 static struct sock *ipqnl __read_mostly;
  57 static LIST_HEAD(queue_list);
  58 static DEFINE_MUTEX(ipqnl_mutex);
  59
  60 static void
  61 ipq_issue_verdict(struct ipq_queue_entry *entry, int verdict)
  62 {
  63         local_bh_disable();
  64         nf_reinject(entry->skb, entry->info, verdict);
  65         local_bh_enable();
  66         kfree(entry);
  67 }
  68
  69 static inline void
  70 __ipq_enqueue_entry(struct ipq_queue_entry *entry)
  71 {
  72        list_add(&entry->list, &queue_list);
  73        queue_total++;
  74 }
  75
  76 /*
  77  * Find and return a queued entry matched by cmpfn, or return the last
  78  * entry if cmpfn is NULL.
  79  */
  80 static inline struct ipq_queue_entry *
  81 __ipq_find_entry(ipq_cmpfn cmpfn, unsigned long data)
  82 {
  83         struct list_head *p;
  84
  85         list_for_each_prev(p, &queue_list) {
  86                 struct ipq_queue_entry *entry = (struct ipq_queue_entry *)p;
  87
  88                 if (!cmpfn || cmpfn(entry, data))
  89                         return entry;
  90         }
  91         return NULL;
  92 }
  93
  94 static inline void
  95 __ipq_dequeue_entry(struct ipq_queue_entry *entry)
  96 {
  97         list_del(&entry->list);
  98         queue_total--;
  99 }
 100
 101 static inline struct ipq_queue_entry *
 102 __ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 103 {
 104         struct ipq_queue_entry *entry;
 105
 106         entry = __ipq_find_entry(cmpfn, data);
 107         if (entry == NULL)
 108                 return NULL;
 109
 110         __ipq_dequeue_entry(entry);
 111         return entry;
 112 }
 113
 114
 115 static inline void
 116 __ipq_flush(int verdict)
 117 {
 118         struct ipq_queue_entry *entry;
 119
 120         while ((entry = __ipq_find_dequeue_entry(NULL, 0)))
 121                 ipq_issue_verdict(entry, verdict);
 122 }
 123
 124 static inline int
 125 __ipq_set_mode(unsigned char mode, unsigned int range)
 126 {
 127         int status = 0;
 128
 129         switch(mode) {
 130         case IPQ_COPY_NONE:
 131         case IPQ_COPY_META:
 132                 copy_mode = mode;
 133                 copy_range = 0;
 134                 break;
 135
 136         case IPQ_COPY_PACKET:
 137                 copy_mode = mode;
 138                 copy_range = range;
 139                 if (copy_range > 0xFFFF)
 140                         copy_range = 0xFFFF;
 141                 break;
 142
 143         default:
 144                 status = -EINVAL;
 145
 146         }
 147         return status;
 148 }
 149
 150 static inline void
 151 __ipq_reset(void)
 152 {
 153         peer_pid = 0;
 154         net_disable_timestamp();
 155         __ipq_set_mode(IPQ_COPY_NONE, 0);
 156         __ipq_flush(NF_DROP);
 157 }
 158
 159 static struct ipq_queue_entry *
 160 ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 161 {
 162         struct ipq_queue_entry *entry;
 163
 164         write_lock_bh(&queue_lock);
 165         entry = __ipq_find_dequeue_entry(cmpfn, data);
 166         write_unlock_bh(&queue_lock);
 167         return entry;
 168 }
 169
 170 static void
 171 ipq_flush(int verdict)
 172 {
 173         write_lock_bh(&queue_lock);
 174         __ipq_flush(verdict);
 175         write_unlock_bh(&queue_lock);
 176 }
 177
 178 static struct sk_buff *
 179 ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 180 {
 181         sk_buff_data_t old_tail;
 182         size_t size = 0;
 183         size_t data_len = 0;
 184         struct sk_buff *skb;
 185         struct ipq_packet_msg *pmsg;
 186         struct nlmsghdr *nlh;
 187         struct timeval tv;
 188
 189         read_lock_bh(&queue_lock);
 190
 191         switch (copy_mode) {
 192         case IPQ_COPY_META:
 193         case IPQ_COPY_NONE:
 194                 size = NLMSG_SPACE(sizeof(*pmsg));
 195                 data_len = 0;
 196                 break;
 197
 198         case IPQ_COPY_PACKET:
 199                 if ((entry->skb->ip_summed == CHECKSUM_PARTIAL ||
 200                      entry->skb->ip_summed == CHECKSUM_COMPLETE) &&
 201                     (*errp = skb_checksum_help(entry->skb))) {
 202                         read_unlock_bh(&queue_lock);
 203                         return NULL;
 204                 }
 205                 if (copy_range == 0 || copy_range > entry->skb->len)
 206                         data_len = entry->skb->len;
 207                 else
 208                         data_len = copy_range;
 209
 210                 size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
 211                 break;
 212
 213         default:
 214                 *errp = -EINVAL;
 215                 read_unlock_bh(&queue_lock);
 216                 return NULL;
 217         }
 218
 219         read_unlock_bh(&queue_lock);
 220
 221         skb = alloc_skb(size, GFP_ATOMIC);
 222         if (!skb)
 223                 goto nlmsg_failure;
 224
 225         old_tail = skb->tail;
 226         nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
 227         pmsg = NLMSG_DATA(nlh);
 228         memset(pmsg, 0, sizeof(*pmsg));
 229
 230         pmsg->packet_id       = (unsigned long )entry;
 231         pmsg->data_len        = data_len;
 232         tv = ktime_to_timeval(entry->skb->tstamp);
 233         pmsg->timestamp_sec   = tv.tv_sec;
 234         pmsg->timestamp_usec  = tv.tv_usec;
 235         pmsg->mark            = entry->skb->mark;
 236         pmsg->hook            = entry->info->hook;
 237         pmsg->hw_protocol     = entry->skb->protocol;
 238
 239         if (entry->info->indev)
 240                 strcpy(pmsg->indev_name, entry->info->indev->name);
 241         else
 242                 pmsg->indev_name[0] = '\0';
 243
 244         if (entry->info->outdev)
 245                 strcpy(pmsg->outdev_name, entry->info->outdev->name);
 246         else
 247                 pmsg->outdev_name[0] = '\0';
 248
 249         if (entry->info->indev && entry->skb->dev) {
 250                 pmsg->hw_type = entry->skb->dev->type;
 251                 pmsg->hw_addrlen = dev_parse_header(entry->skb, pmsg->hw_addr);
 252         }
 253
 254         if (data_len)
 255                 if (skb_copy_bits(entry->skb, 0, pmsg->payload, data_len))
 256                         BUG();
 257
 258         nlh->nlmsg_len = skb->tail - old_tail;
 259         return skb;
 260
 261 nlmsg_failure:
 262         if (skb)
 263                 kfree_skb(skb);
 264         *errp = -EINVAL;
 265         printk(KERN_ERR "ip6_queue: error creating packet message\n");
 266         return NULL;
 267 }
 268
 269 static int
 270 ipq_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
 271                    unsigned int queuenum, void *data)
 272 {
 273         int status = -EINVAL;
 274         struct sk_buff *nskb;
 275         struct ipq_queue_entry *entry;
 276
 277         if (copy_mode == IPQ_COPY_NONE)
 278                 return -EAGAIN;
 279
 280         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 281         if (entry == NULL) {
 282                 printk(KERN_ERR "ip6_queue: OOM in ipq_enqueue_packet()\n");
 283                 return -ENOMEM;
 284         }
 285
 286         entry->info = info;
 287         entry->skb = skb;
 288
 289         nskb = ipq_build_packet_message(entry, &status);
 290         if (nskb == NULL)
 291                 goto err_out_free;
 292
 293         write_lock_bh(&queue_lock);
 294
 295         if (!peer_pid)
 296                 goto err_out_free_nskb;
 297
 298         if (queue_total >= queue_maxlen) {
 299                 queue_dropped++;
 300                 status = -ENOSPC;
 301                 if (net_ratelimit())
 302                         printk (KERN_WARNING "ip6_queue: fill at %d entries, "
 303                                 "dropping packet(s).  Dropped: %d\n", queue_total,
 304                                 queue_dropped);
 305                 goto err_out_free_nskb;
 306         }
 307
 308         /* netlink_unicast will either free the nskb or attach it to a socket */
 309         status = netlink_unicast(ipqnl, nskb, peer_pid, MSG_DONTWAIT);
 310         if (status < 0) {
 311                 queue_user_dropped++;
 312                 goto err_out_unlock;
 313         }
 314
 315         __ipq_enqueue_entry(entry);
 316
 317         write_unlock_bh(&queue_lock);
 318         return status;
 319
 320 err_out_free_nskb:
 321         kfree_skb(nskb);
 322
 323 err_out_unlock:
 324         write_unlock_bh(&queue_lock);
 325
 326 err_out_free:
 327         kfree(entry);
 328         return status;
 329 }
 330
 331 static int
 332 ipq_mangle_ipv6(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
 333 {
 334         int diff;
 335         int err;
 336         struct ipv6hdr *user_iph = (struct ipv6hdr *)v->payload;
 337
 338         if (v->data_len < sizeof(*user_iph))
 339                 return 0;
 340         diff = v->data_len - e->skb->len;
 341         if (diff < 0) {
 342                 if (pskb_trim(e->skb, v->data_len))
 343                         return -ENOMEM;
 344         } else if (diff > 0) {
 345                 if (v->data_len > 0xFFFF)
 346                         return -EINVAL;
 347                 if (diff > skb_tailroom(e->skb)) {
 348                         err = pskb_expand_head(e->skb, 0,
 349                                                diff - skb_tailroom(e->skb),
 350                                                GFP_ATOMIC);
 351                         if (err) {
 352                                 printk(KERN_WARNING "ip6_queue: OOM "
 353                                       "in mangle, dropping packet\n");
 354                                 return err;
 355                         }
 356                 }
 357                 skb_put(e->skb, diff);
 358         }
 359         if (!skb_make_writable(e->skb, v->data_len))
 360                 return -ENOMEM;
 361         skb_copy_to_linear_data(e->skb, v->payload, v->data_len);
 362         e->skb->ip_summed = CHECKSUM_NONE;
 363
 364         return 0;
 365 }
 366
 367 static inline int
 368 id_cmp(struct ipq_queue_entry *e, unsigned long id)
 369 {
 370         return (id == (unsigned long )e);
 371 }
 372
 373 static int
 374 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
 375 {
 376         struct ipq_queue_entry *entry;
 377
 378         if (vmsg->value > NF_MAX_VERDICT)
 379                 return -EINVAL;
 380
 381         entry = ipq_find_dequeue_entry(id_cmp, vmsg->id);
 382         if (entry == NULL)
 383                 return -ENOENT;
 384         else {
 385                 int verdict = vmsg->value;
 386
 387                 if (vmsg->data_len && vmsg->data_len == len)
 388                         if (ipq_mangle_ipv6(vmsg, entry) < 0)
 389                                 verdict = NF_DROP;
 390
 391                 ipq_issue_verdict(entry, verdict);
 392                 return 0;
 393         }
 394 }
 395
 396 static int
 397 ipq_set_mode(unsigned char mode, unsigned int range)
 398 {
 399         int status;
 400
 401         write_lock_bh(&queue_lock);
 402         status = __ipq_set_mode(mode, range);
 403         write_unlock_bh(&queue_lock);
 404         return status;
 405 }
 406
 407 static int
 408 ipq_receive_peer(struct ipq_peer_msg *pmsg,
 409                  unsigned char type, unsigned int len)
 410 {
 411         int status = 0;
 412
 413         if (len < sizeof(*pmsg))
 414                 return -EINVAL;
 415
 416         switch (type) {
 417         case IPQM_MODE:
 418                 status = ipq_set_mode(pmsg->msg.mode.value,
 419                                       pmsg->msg.mode.range);
 420                 break;
 421
 422         case IPQM_VERDICT:
 423                 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
 424                         status = -EINVAL;
 425                 else
 426                         status = ipq_set_verdict(&pmsg->msg.verdict,
 427                                                  len - sizeof(*pmsg));
 428                         break;
 429         default:
 430                 status = -EINVAL;
 431         }
 432         return status;
 433 }
 434
 435 static int
 436 dev_cmp(struct ipq_queue_entry *entry, unsigned long ifindex)
 437 {
 438         if (entry->info->indev)
 439                 if (entry->info->indev->ifindex == ifindex)
 440                         return 1;
 441
 442         if (entry->info->outdev)
 443                 if (entry->info->outdev->ifindex == ifindex)
 444                         return 1;
 445
 446         return 0;
 447 }
 448
 449 static void
 450 ipq_dev_drop(int ifindex)
 451 {
 452         struct ipq_queue_entry *entry;
 453
 454         while ((entry = ipq_find_dequeue_entry(dev_cmp, ifindex)) != NULL)
 455                 ipq_issue_verdict(entry, NF_DROP);
 456 }
 457
 458 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 459
 460 static inline void
 461 __ipq_rcv_skb(struct sk_buff *skb)
 462 {
 463         int status, type, pid, flags, nlmsglen, skblen;
 464         struct nlmsghdr *nlh;
 465
 466         skblen = skb->len;
 467         if (skblen < sizeof(*nlh))
 468                 return;
 469
 470         nlh = nlmsg_hdr(skb);
 471         nlmsglen = nlh->nlmsg_len;
 472         if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
 473                 return;
 474
 475         pid = nlh->nlmsg_pid;
 476         flags = nlh->nlmsg_flags;
 477
 478         if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
 479                 RCV_SKB_FAIL(-EINVAL);
 480
 481         if (flags & MSG_TRUNC)
 482                 RCV_SKB_FAIL(-ECOMM);
 483
 484         type = nlh->nlmsg_type;
 485         if (type < NLMSG_NOOP || type >= IPQM_MAX)
 486                 RCV_SKB_FAIL(-EINVAL);
 487
 488         if (type <= IPQM_BASE)
 489                 return;
 490
 491         if (security_netlink_recv(skb, CAP_NET_ADMIN))
 492                 RCV_SKB_FAIL(-EPERM);
 493
 494         write_lock_bh(&queue_lock);
 495
 496         if (peer_pid) {
 497                 if (peer_pid != pid) {
 498                         write_unlock_bh(&queue_lock);
 499                         RCV_SKB_FAIL(-EBUSY);
 500                 }
 501         } else {
 502                 net_enable_timestamp();
 503                 peer_pid = pid;
 504         }
 505
 506         write_unlock_bh(&queue_lock);
 507
 508         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 509                                   nlmsglen - NLMSG_LENGTH(0));
 510         if (status < 0)
 511                 RCV_SKB_FAIL(status);
 512
 513         if (flags & NLM_F_ACK)
 514                 netlink_ack(skb, nlh, 0);
 515         return;
 516 }
 517
 518 static void
 519 ipq_rcv_skb(struct sk_buff *skb)
 520 {
 521         mutex_lock(&ipqnl_mutex);
 522         __ipq_rcv_skb(skb);
 523         mutex_unlock(&ipqnl_mutex);
 524 }
 525
 526 static int
 527 ipq_rcv_dev_event(struct notifier_block *this,
 528                   unsigned long event, void *ptr)
 529 {
 530         struct net_device *dev = ptr;
 531
 532         if (dev->nd_net != &init_net)
 533                 return NOTIFY_DONE;
 534
 535         /* Drop any packets associated with the downed device */
 536         if (event == NETDEV_DOWN)
 537                 ipq_dev_drop(dev->ifindex);
 538         return NOTIFY_DONE;
 539 }
 540
 541 static struct notifier_block ipq_dev_notifier = {
 542         .notifier_call  = ipq_rcv_dev_event,
 543 };
 544
 545 static int
 546 ipq_rcv_nl_event(struct notifier_block *this,
 547                  unsigned long event, void *ptr)
 548 {
 549         struct netlink_notify *n = ptr;
 550
 551         if (event == NETLINK_URELEASE &&
 552             n->protocol == NETLINK_IP6_FW && n->pid) {
 553                 write_lock_bh(&queue_lock);
 554                 if ((n->net == &init_net) && (n->pid == peer_pid))
 555                         __ipq_reset();
 556                 write_unlock_bh(&queue_lock);
 557         }
 558         return NOTIFY_DONE;
 559 }
 560
 561 static struct notifier_block ipq_nl_notifier = {
 562         .notifier_call  = ipq_rcv_nl_event,
 563 };
 564
 565 static struct ctl_table_header *ipq_sysctl_header;
 566
 567 static ctl_table ipq_table[] = {
 568         {
 569                 .ctl_name       = NET_IPQ_QMAX,
 570                 .procname       = NET_IPQ_QMAX_NAME,
 571                 .data           = &queue_maxlen,
 572                 .maxlen         = sizeof(queue_maxlen),
 573                 .mode           = 0644,
 574                 .proc_handler   = proc_dointvec
 575         },
 576         { .ctl_name = 0 }
 577 };
 578
 579 static ctl_table ipq_dir_table[] = {
 580         {
 581                 .ctl_name       = NET_IPV6,
 582                 .procname       = "ipv6",
 583                 .mode           = 0555,
 584                 .child          = ipq_table
 585         },
 586         { .ctl_name = 0 }
 587 };
 588
 589 static ctl_table ipq_root_table[] = {
 590         {
 591                 .ctl_name       = CTL_NET,
 592                 .procname       = "net",
 593                 .mode           = 0555,
 594                 .child          = ipq_dir_table
 595         },
 596         { .ctl_name = 0 }
 597 };
 598
 599 #ifdef CONFIG_PROC_FS
 600 static int
 601 ipq_get_info(char *buffer, char **start, off_t offset, int length)
 602 {
 603         int len;
 604
 605         read_lock_bh(&queue_lock);
 606
 607         len = sprintf(buffer,
 608                       "Peer PID          : %d\n"
 609                       "Copy mode         : %hu\n"
 610                       "Copy range        : %u\n"
 611                       "Queue length      : %u\n"
 612                       "Queue max. length : %u\n"
 613                       "Queue dropped     : %u\n"
 614                       "Netfilter dropped : %u\n",
 615                       peer_pid,
 616                       copy_mode,
 617                       copy_range,
 618                       queue_total,
 619                       queue_maxlen,
 620                       queue_dropped,
 621                       queue_user_dropped);
 622
 623         read_unlock_bh(&queue_lock);
 624
 625         *start = buffer + offset;
 626         len -= offset;
 627         if (len > length)
 628                 len = length;
 629         else if (len < 0)
 630                 len = 0;
 631         return len;
 632 }
 633 #endif /* CONFIG_PROC_FS */
 634
 635 static struct nf_queue_handler nfqh = {
 636         .name   = "ip6_queue",
 637         .outfn  = &ipq_enqueue_packet,
 638 };
 639
 640 static int __init ip6_queue_init(void)
 641 {
 642         int status = -ENOMEM;
 643         struct proc_dir_entry *proc;
 644
 645         netlink_register_notifier(&ipq_nl_notifier);
 646         ipqnl = netlink_kernel_create(&init_net, NETLINK_IP6_FW, 0,
 647                                       ipq_rcv_skb, NULL, THIS_MODULE);
 648         if (ipqnl == NULL) {
 649                 printk(KERN_ERR "ip6_queue: failed to create netlink socket\n");
 650                 goto cleanup_netlink_notifier;
 651         }
 652
 653         proc = proc_net_create(&init_net, IPQ_PROC_FS_NAME, 0, ipq_get_info);
 654         if (proc)
 655                 proc->owner = THIS_MODULE;
 656         else {
 657                 printk(KERN_ERR "ip6_queue: failed to create proc entry\n");
 658                 goto cleanup_ipqnl;
 659         }
 660
 661         register_netdevice_notifier(&ipq_dev_notifier);
 662         ipq_sysctl_header = register_sysctl_table(ipq_root_table);
 663
 664         status = nf_register_queue_handler(PF_INET6, &nfqh);
 665         if (status < 0) {
 666                 printk(KERN_ERR "ip6_queue: failed to register queue handler\n");
 667                 goto cleanup_sysctl;
 668         }
 669         return status;
 670
 671 cleanup_sysctl:
 672         unregister_sysctl_table(ipq_sysctl_header);
 673         unregister_netdevice_notifier(&ipq_dev_notifier);
 674         proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 675
 676 cleanup_ipqnl:
 677         sock_release(ipqnl->sk_socket);
 678         mutex_lock(&ipqnl_mutex);
 679         mutex_unlock(&ipqnl_mutex);
 680
 681 cleanup_netlink_notifier:
 682         netlink_unregister_notifier(&ipq_nl_notifier);
 683         return status;
 684 }
 685
 686 static void __exit ip6_queue_fini(void)
 687 {
 688         nf_unregister_queue_handlers(&nfqh);
 689         synchronize_net();
 690         ipq_flush(NF_DROP);
 691
 692         unregister_sysctl_table(ipq_sysctl_header);
 693         unregister_netdevice_notifier(&ipq_dev_notifier);
 694         proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 695
 696         sock_release(ipqnl->sk_socket);
 697         mutex_lock(&ipqnl_mutex);
 698         mutex_unlock(&ipqnl_mutex);
 699
 700         netlink_unregister_notifier(&ipq_nl_notifier);
 701 }
 702
 703 MODULE_DESCRIPTION("IPv6 packet queue handler");
 704 MODULE_LICENSE("GPL");
 705
 706 module_init(ip6_queue_init);
 707 module_exit(ip6_queue_fini);