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                 if (entry->skb->dev->hard_header_parse)
 252                         pmsg->hw_addrlen =
 253                                 entry->skb->dev->hard_header_parse(entry->skb,
 254                                                                    pmsg->hw_addr);
 255         }
 256
 257         if (data_len)
 258                 if (skb_copy_bits(entry->skb, 0, pmsg->payload, data_len))
 259                         BUG();
 260
 261         nlh->nlmsg_len = skb->tail - old_tail;
 262         return skb;
 263
 264 nlmsg_failure:
 265         if (skb)
 266                 kfree_skb(skb);
 267         *errp = -EINVAL;
 268         printk(KERN_ERR "ip6_queue: error creating packet message\n");
 269         return NULL;
 270 }
 271
 272 static int
 273 ipq_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
 274                    unsigned int queuenum, void *data)
 275 {
 276         int status = -EINVAL;
 277         struct sk_buff *nskb;
 278         struct ipq_queue_entry *entry;
 279
 280         if (copy_mode == IPQ_COPY_NONE)
 281                 return -EAGAIN;
 282
 283         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 284         if (entry == NULL) {
 285                 printk(KERN_ERR "ip6_queue: OOM in ipq_enqueue_packet()\n");
 286                 return -ENOMEM;
 287         }
 288
 289         entry->info = info;
 290         entry->skb = skb;
 291
 292         nskb = ipq_build_packet_message(entry, &status);
 293         if (nskb == NULL)
 294                 goto err_out_free;
 295
 296         write_lock_bh(&queue_lock);
 297
 298         if (!peer_pid)
 299                 goto err_out_free_nskb;
 300
 301         if (queue_total >= queue_maxlen) {
 302                 queue_dropped++;
 303                 status = -ENOSPC;
 304                 if (net_ratelimit())
 305                         printk (KERN_WARNING "ip6_queue: fill at %d entries, "
 306                                 "dropping packet(s).  Dropped: %d\n", queue_total,
 307                                 queue_dropped);
 308                 goto err_out_free_nskb;
 309         }
 310
 311         /* netlink_unicast will either free the nskb or attach it to a socket */
 312         status = netlink_unicast(ipqnl, nskb, peer_pid, MSG_DONTWAIT);
 313         if (status < 0) {
 314                 queue_user_dropped++;
 315                 goto err_out_unlock;
 316         }
 317
 318         __ipq_enqueue_entry(entry);
 319
 320         write_unlock_bh(&queue_lock);
 321         return status;
 322
 323 err_out_free_nskb:
 324         kfree_skb(nskb);
 325
 326 err_out_unlock:
 327         write_unlock_bh(&queue_lock);
 328
 329 err_out_free:
 330         kfree(entry);
 331         return status;
 332 }
 333
 334 static int
 335 ipq_mangle_ipv6(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
 336 {
 337         int diff;
 338         struct ipv6hdr *user_iph = (struct ipv6hdr *)v->payload;
 339
 340         if (v->data_len < sizeof(*user_iph))
 341                 return 0;
 342         diff = v->data_len - e->skb->len;
 343         if (diff < 0) {
 344                 if (pskb_trim(e->skb, v->data_len))
 345                         return -ENOMEM;
 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         if (!skb_make_writable(&e->skb, v->data_len))
 369                 return -ENOMEM;
 370         skb_copy_to_linear_data(e->skb, v->payload, v->data_len);
 371         e->skb->ip_summed = CHECKSUM_NONE;
 372
 373         return 0;
 374 }
 375
 376 static inline int
 377 id_cmp(struct ipq_queue_entry *e, unsigned long id)
 378 {
 379         return (id == (unsigned long )e);
 380 }
 381
 382 static int
 383 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
 384 {
 385         struct ipq_queue_entry *entry;
 386
 387         if (vmsg->value > NF_MAX_VERDICT)
 388                 return -EINVAL;
 389
 390         entry = ipq_find_dequeue_entry(id_cmp, vmsg->id);
 391         if (entry == NULL)
 392                 return -ENOENT;
 393         else {
 394                 int verdict = vmsg->value;
 395
 396                 if (vmsg->data_len && vmsg->data_len == len)
 397                         if (ipq_mangle_ipv6(vmsg, entry) < 0)
 398                                 verdict = NF_DROP;
 399
 400                 ipq_issue_verdict(entry, verdict);
 401                 return 0;
 402         }
 403 }
 404
 405 static int
 406 ipq_set_mode(unsigned char mode, unsigned int range)
 407 {
 408         int status;
 409
 410         write_lock_bh(&queue_lock);
 411         status = __ipq_set_mode(mode, range);
 412         write_unlock_bh(&queue_lock);
 413         return status;
 414 }
 415
 416 static int
 417 ipq_receive_peer(struct ipq_peer_msg *pmsg,
 418                  unsigned char type, unsigned int len)
 419 {
 420         int status = 0;
 421
 422         if (len < sizeof(*pmsg))
 423                 return -EINVAL;
 424
 425         switch (type) {
 426         case IPQM_MODE:
 427                 status = ipq_set_mode(pmsg->msg.mode.value,
 428                                       pmsg->msg.mode.range);
 429                 break;
 430
 431         case IPQM_VERDICT:
 432                 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
 433                         status = -EINVAL;
 434                 else
 435                         status = ipq_set_verdict(&pmsg->msg.verdict,
 436                                                  len - sizeof(*pmsg));
 437                         break;
 438         default:
 439                 status = -EINVAL;
 440         }
 441         return status;
 442 }
 443
 444 static int
 445 dev_cmp(struct ipq_queue_entry *entry, unsigned long ifindex)
 446 {
 447         if (entry->info->indev)
 448                 if (entry->info->indev->ifindex == ifindex)
 449                         return 1;
 450
 451         if (entry->info->outdev)
 452                 if (entry->info->outdev->ifindex == ifindex)
 453                         return 1;
 454
 455         return 0;
 456 }
 457
 458 static void
 459 ipq_dev_drop(int ifindex)
 460 {
 461         struct ipq_queue_entry *entry;
 462
 463         while ((entry = ipq_find_dequeue_entry(dev_cmp, ifindex)) != NULL)
 464                 ipq_issue_verdict(entry, NF_DROP);
 465 }
 466
 467 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 468
 469 static inline void
 470 ipq_rcv_skb(struct sk_buff *skb)
 471 {
 472         int status, type, pid, flags, nlmsglen, skblen;
 473         struct nlmsghdr *nlh;
 474
 475         skblen = skb->len;
 476         if (skblen < sizeof(*nlh))
 477                 return;
 478
 479         nlh = nlmsg_hdr(skb);
 480         nlmsglen = nlh->nlmsg_len;
 481         if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
 482                 return;
 483
 484         pid = nlh->nlmsg_pid;
 485         flags = nlh->nlmsg_flags;
 486
 487         if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
 488                 RCV_SKB_FAIL(-EINVAL);
 489
 490         if (flags & MSG_TRUNC)
 491                 RCV_SKB_FAIL(-ECOMM);
 492
 493         type = nlh->nlmsg_type;
 494         if (type < NLMSG_NOOP || type >= IPQM_MAX)
 495                 RCV_SKB_FAIL(-EINVAL);
 496
 497         if (type <= IPQM_BASE)
 498                 return;
 499
 500         if (security_netlink_recv(skb, CAP_NET_ADMIN))
 501                 RCV_SKB_FAIL(-EPERM);
 502
 503         write_lock_bh(&queue_lock);
 504
 505         if (peer_pid) {
 506                 if (peer_pid != pid) {
 507                         write_unlock_bh(&queue_lock);
 508                         RCV_SKB_FAIL(-EBUSY);
 509                 }
 510         } else {
 511                 net_enable_timestamp();
 512                 peer_pid = pid;
 513         }
 514
 515         write_unlock_bh(&queue_lock);
 516
 517         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 518                                   nlmsglen - NLMSG_LENGTH(0));
 519         if (status < 0)
 520                 RCV_SKB_FAIL(status);
 521
 522         if (flags & NLM_F_ACK)
 523                 netlink_ack(skb, nlh, 0);
 524         return;
 525 }
 526
 527 static void
 528 ipq_rcv_sk(struct sock *sk, int len)
 529 {
 530         struct sk_buff *skb;
 531         unsigned int qlen;
 532
 533         mutex_lock(&ipqnl_mutex);
 534
 535         for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
 536                 skb = skb_dequeue(&sk->sk_receive_queue);
 537                 ipq_rcv_skb(skb);
 538                 kfree_skb(skb);
 539         }
 540
 541         mutex_unlock(&ipqnl_mutex);
 542 }
 543
 544 static int
 545 ipq_rcv_dev_event(struct notifier_block *this,
 546                   unsigned long event, void *ptr)
 547 {
 548         struct net_device *dev = ptr;
 549
 550         /* Drop any packets associated with the downed device */
 551         if (event == NETDEV_DOWN)
 552                 ipq_dev_drop(dev->ifindex);
 553         return NOTIFY_DONE;
 554 }
 555
 556 static struct notifier_block ipq_dev_notifier = {
 557         .notifier_call  = ipq_rcv_dev_event,
 558 };
 559
 560 static int
 561 ipq_rcv_nl_event(struct notifier_block *this,
 562                  unsigned long event, void *ptr)
 563 {
 564         struct netlink_notify *n = ptr;
 565
 566         if (event == NETLINK_URELEASE &&
 567             n->protocol == NETLINK_IP6_FW && n->pid) {
 568                 write_lock_bh(&queue_lock);
 569                 if (n->pid == peer_pid)
 570                         __ipq_reset();
 571                 write_unlock_bh(&queue_lock);
 572         }
 573         return NOTIFY_DONE;
 574 }
 575
 576 static struct notifier_block ipq_nl_notifier = {
 577         .notifier_call  = ipq_rcv_nl_event,
 578 };
 579
 580 static struct ctl_table_header *ipq_sysctl_header;
 581
 582 static ctl_table ipq_table[] = {
 583         {
 584                 .ctl_name       = NET_IPQ_QMAX,
 585                 .procname       = NET_IPQ_QMAX_NAME,
 586                 .data           = &queue_maxlen,
 587                 .maxlen         = sizeof(queue_maxlen),
 588                 .mode           = 0644,
 589                 .proc_handler   = proc_dointvec
 590         },
 591         { .ctl_name = 0 }
 592 };
 593
 594 static ctl_table ipq_dir_table[] = {
 595         {
 596                 .ctl_name       = NET_IPV6,
 597                 .procname       = "ipv6",
 598                 .mode           = 0555,
 599                 .child          = ipq_table
 600         },
 601         { .ctl_name = 0 }
 602 };
 603
 604 static ctl_table ipq_root_table[] = {
 605         {
 606                 .ctl_name       = CTL_NET,
 607                 .procname       = "net",
 608                 .mode           = 0555,
 609                 .child          = ipq_dir_table
 610         },
 611         { .ctl_name = 0 }
 612 };
 613
 614 #ifdef CONFIG_PROC_FS
 615 static int
 616 ipq_get_info(char *buffer, char **start, off_t offset, int length)
 617 {
 618         int len;
 619
 620         read_lock_bh(&queue_lock);
 621
 622         len = sprintf(buffer,
 623                       "Peer PID          : %d\n"
 624                       "Copy mode         : %hu\n"
 625                       "Copy range        : %u\n"
 626                       "Queue length      : %u\n"
 627                       "Queue max. length : %u\n"
 628                       "Queue dropped     : %u\n"
 629                       "Netfilter dropped : %u\n",
 630                       peer_pid,
 631                       copy_mode,
 632                       copy_range,
 633                       queue_total,
 634                       queue_maxlen,
 635                       queue_dropped,
 636                       queue_user_dropped);
 637
 638         read_unlock_bh(&queue_lock);
 639
 640         *start = buffer + offset;
 641         len -= offset;
 642         if (len > length)
 643                 len = length;
 644         else if (len < 0)
 645                 len = 0;
 646         return len;
 647 }
 648 #endif /* CONFIG_PROC_FS */
 649
 650 static struct nf_queue_handler nfqh = {
 651         .name   = "ip6_queue",
 652         .outfn  = &ipq_enqueue_packet,
 653 };
 654
 655 static int __init ip6_queue_init(void)
 656 {
 657         int status = -ENOMEM;
 658         struct proc_dir_entry *proc;
 659
 660         netlink_register_notifier(&ipq_nl_notifier);
 661         ipqnl = netlink_kernel_create(NETLINK_IP6_FW, 0, ipq_rcv_sk, NULL,
 662                                       THIS_MODULE);
 663         if (ipqnl == NULL) {
 664                 printk(KERN_ERR "ip6_queue: failed to create netlink socket\n");
 665                 goto cleanup_netlink_notifier;
 666         }
 667
 668         proc = proc_net_create(&init_net, IPQ_PROC_FS_NAME, 0, ipq_get_info);
 669         if (proc)
 670                 proc->owner = THIS_MODULE;
 671         else {
 672                 printk(KERN_ERR "ip6_queue: failed to create proc entry\n");
 673                 goto cleanup_ipqnl;
 674         }
 675
 676         register_netdevice_notifier(&ipq_dev_notifier);
 677         ipq_sysctl_header = register_sysctl_table(ipq_root_table);
 678
 679         status = nf_register_queue_handler(PF_INET6, &nfqh);
 680         if (status < 0) {
 681                 printk(KERN_ERR "ip6_queue: failed to register queue handler\n");
 682                 goto cleanup_sysctl;
 683         }
 684         return status;
 685
 686 cleanup_sysctl:
 687         unregister_sysctl_table(ipq_sysctl_header);
 688         unregister_netdevice_notifier(&ipq_dev_notifier);
 689         proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 690
 691 cleanup_ipqnl:
 692         sock_release(ipqnl->sk_socket);
 693         mutex_lock(&ipqnl_mutex);
 694         mutex_unlock(&ipqnl_mutex);
 695
 696 cleanup_netlink_notifier:
 697         netlink_unregister_notifier(&ipq_nl_notifier);
 698         return status;
 699 }
 700
 701 static void __exit ip6_queue_fini(void)
 702 {
 703         nf_unregister_queue_handlers(&nfqh);
 704         synchronize_net();
 705         ipq_flush(NF_DROP);
 706
 707         unregister_sysctl_table(ipq_sysctl_header);
 708         unregister_netdevice_notifier(&ipq_dev_notifier);
 709         proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 710
 711         sock_release(ipqnl->sk_socket);
 712         mutex_lock(&ipqnl_mutex);
 713         mutex_unlock(&ipqnl_mutex);
 714
 715         netlink_unregister_notifier(&ipq_nl_notifier);
 716 }
 717
 718 MODULE_DESCRIPTION("IPv6 packet queue handler");
 719 MODULE_LICENSE("GPL");
 720
 721 module_init(ip6_queue_init);
 722 module_exit(ip6_queue_fini);