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/sock.h>
  28 #include <net/ipv6.h>
  29 #include <net/ip6_route.h>
  30 #include <linux/netfilter_ipv4/ip_queue.h>
  31 #include <linux/netfilter_ipv4/ip_tables.h>
  32 #include <linux/netfilter_ipv6/ip6_tables.h>
  33
  34 #define IPQ_QMAX_DEFAULT 1024
  35 #define IPQ_PROC_FS_NAME "ip6_queue"
  36 #define NET_IPQ_QMAX 2088
  37 #define NET_IPQ_QMAX_NAME "ip6_queue_maxlen"
  38
  39 struct ipq_queue_entry {
  40         struct list_head list;
  41         struct nf_info *info;
  42         struct sk_buff *skb;
  43 };
  44
  45 typedef int (*ipq_cmpfn)(struct ipq_queue_entry *, unsigned long);
  46
  47 static unsigned char copy_mode __read_mostly = IPQ_COPY_NONE;
  48 static unsigned int queue_maxlen __read_mostly = IPQ_QMAX_DEFAULT;
  49 static DEFINE_RWLOCK(queue_lock);
  50 static int peer_pid __read_mostly;
  51 static unsigned int copy_range __read_mostly;
  52 static unsigned int queue_total;
  53 static unsigned int queue_dropped = 0;
  54 static unsigned int queue_user_dropped = 0;
  55 static struct sock *ipqnl __read_mostly;
  56 static LIST_HEAD(queue_list);
  57 static DEFINE_MUTEX(ipqnl_mutex);
  58
  59 static void
  60 ipq_issue_verdict(struct ipq_queue_entry *entry, int verdict)
  61 {
  62         local_bh_disable();
  63         nf_reinject(entry->skb, entry->info, verdict);
  64         local_bh_enable();
  65         kfree(entry);
  66 }
  67
  68 static inline void
  69 __ipq_enqueue_entry(struct ipq_queue_entry *entry)
  70 {
  71        list_add(&entry->list, &queue_list);
  72        queue_total++;
  73 }
  74
  75 /*
  76  * Find and return a queued entry matched by cmpfn, or return the last
  77  * entry if cmpfn is NULL.
  78  */
  79 static inline struct ipq_queue_entry *
  80 __ipq_find_entry(ipq_cmpfn cmpfn, unsigned long data)
  81 {
  82         struct list_head *p;
  83
  84         list_for_each_prev(p, &queue_list) {
  85                 struct ipq_queue_entry *entry = (struct ipq_queue_entry *)p;
  86
  87                 if (!cmpfn || cmpfn(entry, data))
  88                         return entry;
  89         }
  90         return NULL;
  91 }
  92
  93 static inline void
  94 __ipq_dequeue_entry(struct ipq_queue_entry *entry)
  95 {
  96         list_del(&entry->list);
  97         queue_total--;
  98 }
  99
 100 static inline struct ipq_queue_entry *
 101 __ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 102 {
 103         struct ipq_queue_entry *entry;
 104
 105         entry = __ipq_find_entry(cmpfn, data);
 106         if (entry == NULL)
 107                 return NULL;
 108
 109         __ipq_dequeue_entry(entry);
 110         return entry;
 111 }
 112
 113
 114 static inline void
 115 __ipq_flush(int verdict)
 116 {
 117         struct ipq_queue_entry *entry;
 118
 119         while ((entry = __ipq_find_dequeue_entry(NULL, 0)))
 120                 ipq_issue_verdict(entry, verdict);
 121 }
 122
 123 static inline int
 124 __ipq_set_mode(unsigned char mode, unsigned int range)
 125 {
 126         int status = 0;
 127
 128         switch(mode) {
 129         case IPQ_COPY_NONE:
 130         case IPQ_COPY_META:
 131                 copy_mode = mode;
 132                 copy_range = 0;
 133                 break;
 134
 135         case IPQ_COPY_PACKET:
 136                 copy_mode = mode;
 137                 copy_range = range;
 138                 if (copy_range > 0xFFFF)
 139                         copy_range = 0xFFFF;
 140                 break;
 141
 142         default:
 143                 status = -EINVAL;
 144
 145         }
 146         return status;
 147 }
 148
 149 static inline void
 150 __ipq_reset(void)
 151 {
 152         peer_pid = 0;
 153         net_disable_timestamp();
 154         __ipq_set_mode(IPQ_COPY_NONE, 0);
 155         __ipq_flush(NF_DROP);
 156 }
 157
 158 static struct ipq_queue_entry *
 159 ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 160 {
 161         struct ipq_queue_entry *entry;
 162
 163         write_lock_bh(&queue_lock);
 164         entry = __ipq_find_dequeue_entry(cmpfn, data);
 165         write_unlock_bh(&queue_lock);
 166         return entry;
 167 }
 168
 169 static void
 170 ipq_flush(int verdict)
 171 {
 172         write_lock_bh(&queue_lock);
 173         __ipq_flush(verdict);
 174         write_unlock_bh(&queue_lock);
 175 }
 176
 177 static struct sk_buff *
 178 ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 179 {
 180         sk_buff_data_t old_tail;
 181         size_t size = 0;
 182         size_t data_len = 0;
 183         struct sk_buff *skb;
 184         struct ipq_packet_msg *pmsg;
 185         struct nlmsghdr *nlh;
 186         struct timeval tv;
 187
 188         read_lock_bh(&queue_lock);
 189
 190         switch (copy_mode) {
 191         case IPQ_COPY_META:
 192         case IPQ_COPY_NONE:
 193                 size = NLMSG_SPACE(sizeof(*pmsg));
 194                 data_len = 0;
 195                 break;
 196
 197         case IPQ_COPY_PACKET:
 198                 if ((entry->skb->ip_summed == CHECKSUM_PARTIAL ||
 199                      entry->skb->ip_summed == CHECKSUM_COMPLETE) &&
 200                     (*errp = skb_checksum_help(entry->skb))) {
 201                         read_unlock_bh(&queue_lock);
 202                         return NULL;
 203                 }
 204                 if (copy_range == 0 || copy_range > entry->skb->len)
 205                         data_len = entry->skb->len;
 206                 else
 207                         data_len = copy_range;
 208
 209                 size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
 210                 break;
 211
 212         default:
 213                 *errp = -EINVAL;
 214                 read_unlock_bh(&queue_lock);
 215                 return NULL;
 216         }
 217
 218         read_unlock_bh(&queue_lock);
 219
 220         skb = alloc_skb(size, GFP_ATOMIC);
 221         if (!skb)
 222                 goto nlmsg_failure;
 223
 224         old_tail = skb->tail;
 225         nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
 226         pmsg = NLMSG_DATA(nlh);
 227         memset(pmsg, 0, sizeof(*pmsg));
 228
 229         pmsg->packet_id       = (unsigned long )entry;
 230         pmsg->data_len        = data_len;
 231         tv = ktime_to_timeval(entry->skb->tstamp);
 232         pmsg->timestamp_sec   = tv.tv_sec;
 233         pmsg->timestamp_usec  = tv.tv_usec;
 234         pmsg->mark            = entry->skb->mark;
 235         pmsg->hook            = entry->info->hook;
 236         pmsg->hw_protocol     = entry->skb->protocol;
 237
 238         if (entry->info->indev)
 239                 strcpy(pmsg->indev_name, entry->info->indev->name);
 240         else
 241                 pmsg->indev_name[0] = '\0';
 242
 243         if (entry->info->outdev)
 244                 strcpy(pmsg->outdev_name, entry->info->outdev->name);
 245         else
 246                 pmsg->outdev_name[0] = '\0';
 247
 248         if (entry->info->indev && entry->skb->dev) {
 249                 pmsg->hw_type = entry->skb->dev->type;
 250                 if (entry->skb->dev->hard_header_parse)
 251                         pmsg->hw_addrlen =
 252                                 entry->skb->dev->hard_header_parse(entry->skb,
 253                                                                    pmsg->hw_addr);
 254         }
 255
 256         if (data_len)
 257                 if (skb_copy_bits(entry->skb, 0, pmsg->payload, data_len))
 258                         BUG();
 259
 260         nlh->nlmsg_len = skb->tail - old_tail;
 261         return skb;
 262
 263 nlmsg_failure:
 264         if (skb)
 265                 kfree_skb(skb);
 266         *errp = -EINVAL;
 267         printk(KERN_ERR "ip6_queue: error creating packet message\n");
 268         return NULL;
 269 }
 270
 271 static int
 272 ipq_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
 273                    unsigned int queuenum, void *data)
 274 {
 275         int status = -EINVAL;
 276         struct sk_buff *nskb;
 277         struct ipq_queue_entry *entry;
 278
 279         if (copy_mode == IPQ_COPY_NONE)
 280                 return -EAGAIN;
 281
 282         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 283         if (entry == NULL) {
 284                 printk(KERN_ERR "ip6_queue: OOM in ipq_enqueue_packet()\n");
 285                 return -ENOMEM;
 286         }
 287
 288         entry->info = info;
 289         entry->skb = skb;
 290
 291         nskb = ipq_build_packet_message(entry, &status);
 292         if (nskb == NULL)
 293                 goto err_out_free;
 294
 295         write_lock_bh(&queue_lock);
 296
 297         if (!peer_pid)
 298                 goto err_out_free_nskb;
 299
 300         if (queue_total >= queue_maxlen) {
 301                 queue_dropped++;
 302                 status = -ENOSPC;
 303                 if (net_ratelimit())
 304                         printk (KERN_WARNING "ip6_queue: fill at %d entries, "
 305                                 "dropping packet(s).  Dropped: %d\n", queue_total,
 306                                 queue_dropped);
 307                 goto err_out_free_nskb;
 308         }
 309
 310         /* netlink_unicast will either free the nskb or attach it to a socket */
 311         status = netlink_unicast(ipqnl, nskb, peer_pid, MSG_DONTWAIT);
 312         if (status < 0) {
 313                 queue_user_dropped++;
 314                 goto err_out_unlock;
 315         }
 316
 317         __ipq_enqueue_entry(entry);
 318
 319         write_unlock_bh(&queue_lock);
 320         return status;
 321
 322 err_out_free_nskb:
 323         kfree_skb(nskb);
 324
 325 err_out_unlock:
 326         write_unlock_bh(&queue_lock);
 327
 328 err_out_free:
 329         kfree(entry);
 330         return status;
 331 }
 332
 333 static int
 334 ipq_mangle_ipv6(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
 335 {
 336         int diff;
 337         struct ipv6hdr *user_iph = (struct ipv6hdr *)v->payload;
 338
 339         if (v->data_len < sizeof(*user_iph))
 340                 return 0;
 341         diff = v->data_len - e->skb->len;
 342         if (diff < 0) {
 343                 if (pskb_trim(e->skb, v->data_len))
 344                         return -ENOMEM;
 345         } else if (diff > 0) {
 346                 if (v->data_len > 0xFFFF)
 347                         return -EINVAL;
 348                 if (diff > skb_tailroom(e->skb)) {
 349                         struct sk_buff *newskb;
 350
 351                         newskb = skb_copy_expand(e->skb,
 352                                                  skb_headroom(e->skb),
 353                                                  diff,
 354                                                  GFP_ATOMIC);
 355                         if (newskb == NULL) {
 356                                 printk(KERN_WARNING "ip6_queue: OOM "
 357                                       "in mangle, dropping packet\n");
 358                                 return -ENOMEM;
 359                         }
 360                         if (e->skb->sk)
 361                                 skb_set_owner_w(newskb, e->skb->sk);
 362                         kfree_skb(e->skb);
 363                         e->skb = newskb;
 364                 }
 365                 skb_put(e->skb, diff);
 366         }
 367         if (!skb_make_writable(&e->skb, v->data_len))
 368                 return -ENOMEM;
 369         skb_copy_to_linear_data(e->skb, v->payload, v->data_len);
 370         e->skb->ip_summed = CHECKSUM_NONE;
 371
 372         return 0;
 373 }
 374
 375 static inline int
 376 id_cmp(struct ipq_queue_entry *e, unsigned long id)
 377 {
 378         return (id == (unsigned long )e);
 379 }
 380
 381 static int
 382 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
 383 {
 384         struct ipq_queue_entry *entry;
 385
 386         if (vmsg->value > NF_MAX_VERDICT)
 387                 return -EINVAL;
 388
 389         entry = ipq_find_dequeue_entry(id_cmp, vmsg->id);
 390         if (entry == NULL)
 391                 return -ENOENT;
 392         else {
 393                 int verdict = vmsg->value;
 394
 395                 if (vmsg->data_len && vmsg->data_len == len)
 396                         if (ipq_mangle_ipv6(vmsg, entry) < 0)
 397                                 verdict = NF_DROP;
 398
 399                 ipq_issue_verdict(entry, verdict);
 400                 return 0;
 401         }
 402 }
 403
 404 static int
 405 ipq_set_mode(unsigned char mode, unsigned int range)
 406 {
 407         int status;
 408
 409         write_lock_bh(&queue_lock);
 410         status = __ipq_set_mode(mode, range);
 411         write_unlock_bh(&queue_lock);
 412         return status;
 413 }
 414
 415 static int
 416 ipq_receive_peer(struct ipq_peer_msg *pmsg,
 417                  unsigned char type, unsigned int len)
 418 {
 419         int status = 0;
 420
 421         if (len < sizeof(*pmsg))
 422                 return -EINVAL;
 423
 424         switch (type) {
 425         case IPQM_MODE:
 426                 status = ipq_set_mode(pmsg->msg.mode.value,
 427                                       pmsg->msg.mode.range);
 428                 break;
 429
 430         case IPQM_VERDICT:
 431                 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
 432                         status = -EINVAL;
 433                 else
 434                         status = ipq_set_verdict(&pmsg->msg.verdict,
 435                                                  len - sizeof(*pmsg));
 436                         break;
 437         default:
 438                 status = -EINVAL;
 439         }
 440         return status;
 441 }
 442
 443 static int
 444 dev_cmp(struct ipq_queue_entry *entry, unsigned long ifindex)
 445 {
 446         if (entry->info->indev)
 447                 if (entry->info->indev->ifindex == ifindex)
 448                         return 1;
 449
 450         if (entry->info->outdev)
 451                 if (entry->info->outdev->ifindex == ifindex)
 452                         return 1;
 453
 454         return 0;
 455 }
 456
 457 static void
 458 ipq_dev_drop(int ifindex)
 459 {
 460         struct ipq_queue_entry *entry;
 461
 462         while ((entry = ipq_find_dequeue_entry(dev_cmp, ifindex)) != NULL)
 463                 ipq_issue_verdict(entry, NF_DROP);
 464 }
 465
 466 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 467
 468 static inline void
 469 ipq_rcv_skb(struct sk_buff *skb)
 470 {
 471         int status, type, pid, flags, nlmsglen, skblen;
 472         struct nlmsghdr *nlh;
 473
 474         skblen = skb->len;
 475         if (skblen < sizeof(*nlh))
 476                 return;
 477
 478         nlh = nlmsg_hdr(skb);
 479         nlmsglen = nlh->nlmsg_len;
 480         if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
 481                 return;
 482
 483         pid = nlh->nlmsg_pid;
 484         flags = nlh->nlmsg_flags;
 485
 486         if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
 487                 RCV_SKB_FAIL(-EINVAL);
 488
 489         if (flags & MSG_TRUNC)
 490                 RCV_SKB_FAIL(-ECOMM);
 491
 492         type = nlh->nlmsg_type;
 493         if (type < NLMSG_NOOP || type >= IPQM_MAX)
 494                 RCV_SKB_FAIL(-EINVAL);
 495
 496         if (type <= IPQM_BASE)
 497                 return;
 498
 499         if (security_netlink_recv(skb, CAP_NET_ADMIN))
 500                 RCV_SKB_FAIL(-EPERM);
 501
 502         write_lock_bh(&queue_lock);
 503
 504         if (peer_pid) {
 505                 if (peer_pid != pid) {
 506                         write_unlock_bh(&queue_lock);
 507                         RCV_SKB_FAIL(-EBUSY);
 508                 }
 509         } else {
 510                 net_enable_timestamp();
 511                 peer_pid = pid;
 512         }
 513
 514         write_unlock_bh(&queue_lock);
 515
 516         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 517                                   nlmsglen - NLMSG_LENGTH(0));
 518         if (status < 0)
 519                 RCV_SKB_FAIL(status);
 520
 521         if (flags & NLM_F_ACK)
 522                 netlink_ack(skb, nlh, 0);
 523         return;
 524 }
 525
 526 static void
 527 ipq_rcv_sk(struct sock *sk, int len)
 528 {
 529         struct sk_buff *skb;
 530         unsigned int qlen;
 531
 532         mutex_lock(&ipqnl_mutex);
 533
 534         for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
 535                 skb = skb_dequeue(&sk->sk_receive_queue);
 536                 ipq_rcv_skb(skb);
 537                 kfree_skb(skb);
 538         }
 539
 540         mutex_unlock(&ipqnl_mutex);
 541 }
 542
 543 static int
 544 ipq_rcv_dev_event(struct notifier_block *this,
 545                   unsigned long event, void *ptr)
 546 {
 547         struct net_device *dev = ptr;
 548
 549         /* Drop any packets associated with the downed device */
 550         if (event == NETDEV_DOWN)
 551                 ipq_dev_drop(dev->ifindex);
 552         return NOTIFY_DONE;
 553 }
 554
 555 static struct notifier_block ipq_dev_notifier = {
 556         .notifier_call  = ipq_rcv_dev_event,
 557 };
 558
 559 static int
 560 ipq_rcv_nl_event(struct notifier_block *this,
 561                  unsigned long event, void *ptr)
 562 {
 563         struct netlink_notify *n = ptr;
 564
 565         if (event == NETLINK_URELEASE &&
 566             n->protocol == NETLINK_IP6_FW && n->pid) {
 567                 write_lock_bh(&queue_lock);
 568                 if (n->pid == peer_pid)
 569                         __ipq_reset();
 570                 write_unlock_bh(&queue_lock);
 571         }
 572         return NOTIFY_DONE;
 573 }
 574
 575 static struct notifier_block ipq_nl_notifier = {
 576         .notifier_call  = ipq_rcv_nl_event,
 577 };
 578
 579 static struct ctl_table_header *ipq_sysctl_header;
 580
 581 static ctl_table ipq_table[] = {
 582         {
 583                 .ctl_name       = NET_IPQ_QMAX,
 584                 .procname       = NET_IPQ_QMAX_NAME,
 585                 .data           = &queue_maxlen,
 586                 .maxlen         = sizeof(queue_maxlen),
 587                 .mode           = 0644,
 588                 .proc_handler   = proc_dointvec
 589         },
 590         { .ctl_name = 0 }
 591 };
 592
 593 static ctl_table ipq_dir_table[] = {
 594         {
 595                 .ctl_name       = NET_IPV6,
 596                 .procname       = "ipv6",
 597                 .mode           = 0555,
 598                 .child          = ipq_table
 599         },
 600         { .ctl_name = 0 }
 601 };
 602
 603 static ctl_table ipq_root_table[] = {
 604         {
 605                 .ctl_name       = CTL_NET,
 606                 .procname       = "net",
 607                 .mode           = 0555,
 608                 .child          = ipq_dir_table
 609         },
 610         { .ctl_name = 0 }
 611 };
 612
 613 #ifdef CONFIG_PROC_FS
 614 static int
 615 ipq_get_info(char *buffer, char **start, off_t offset, int length)
 616 {
 617         int len;
 618
 619         read_lock_bh(&queue_lock);
 620
 621         len = sprintf(buffer,
 622                       "Peer PID          : %d\n"
 623                       "Copy mode         : %hu\n"
 624                       "Copy range        : %u\n"
 625                       "Queue length      : %u\n"
 626                       "Queue max. length : %u\n"
 627                       "Queue dropped     : %u\n"
 628                       "Netfilter dropped : %u\n",
 629                       peer_pid,
 630                       copy_mode,
 631                       copy_range,
 632                       queue_total,
 633                       queue_maxlen,
 634                       queue_dropped,
 635                       queue_user_dropped);
 636
 637         read_unlock_bh(&queue_lock);
 638
 639         *start = buffer + offset;
 640         len -= offset;
 641         if (len > length)
 642                 len = length;
 643         else if (len < 0)
 644                 len = 0;
 645         return len;
 646 }
 647 #endif /* CONFIG_PROC_FS */
 648
 649 static struct nf_queue_handler nfqh = {
 650         .name   = "ip6_queue",
 651         .outfn  = &ipq_enqueue_packet,
 652 };
 653
 654 static int __init ip6_queue_init(void)
 655 {
 656         int status = -ENOMEM;
 657         struct proc_dir_entry *proc;
 658
 659         netlink_register_notifier(&ipq_nl_notifier);
 660         ipqnl = netlink_kernel_create(NETLINK_IP6_FW, 0, ipq_rcv_sk, NULL,
 661                                       THIS_MODULE);
 662         if (ipqnl == NULL) {
 663                 printk(KERN_ERR "ip6_queue: failed to create netlink socket\n");
 664                 goto cleanup_netlink_notifier;
 665         }
 666
 667         proc = proc_net_create(IPQ_PROC_FS_NAME, 0, ipq_get_info);
 668         if (proc)
 669                 proc->owner = THIS_MODULE;
 670         else {
 671                 printk(KERN_ERR "ip6_queue: failed to create proc entry\n");
 672                 goto cleanup_ipqnl;
 673         }
 674
 675         register_netdevice_notifier(&ipq_dev_notifier);
 676         ipq_sysctl_header = register_sysctl_table(ipq_root_table);
 677
 678         status = nf_register_queue_handler(PF_INET6, &nfqh);
 679         if (status < 0) {
 680                 printk(KERN_ERR "ip6_queue: failed to register queue handler\n");
 681                 goto cleanup_sysctl;
 682         }
 683         return status;
 684
 685 cleanup_sysctl:
 686         unregister_sysctl_table(ipq_sysctl_header);
 687         unregister_netdevice_notifier(&ipq_dev_notifier);
 688         proc_net_remove(IPQ_PROC_FS_NAME);
 689
 690 cleanup_ipqnl:
 691         sock_release(ipqnl->sk_socket);
 692         mutex_lock(&ipqnl_mutex);
 693         mutex_unlock(&ipqnl_mutex);
 694
 695 cleanup_netlink_notifier:
 696         netlink_unregister_notifier(&ipq_nl_notifier);
 697         return status;
 698 }
 699
 700 static void __exit ip6_queue_fini(void)
 701 {
 702         nf_unregister_queue_handlers(&nfqh);
 703         synchronize_net();
 704         ipq_flush(NF_DROP);
 705
 706         unregister_sysctl_table(ipq_sysctl_header);
 707         unregister_netdevice_notifier(&ipq_dev_notifier);
 708         proc_net_remove(IPQ_PROC_FS_NAME);
 709
 710         sock_release(ipqnl->sk_socket);
 711         mutex_lock(&ipqnl_mutex);
 712         mutex_unlock(&ipqnl_mutex);
 713
 714         netlink_unregister_notifier(&ipq_nl_notifier);
 715 }
 716
 717 MODULE_DESCRIPTION("IPv6 packet queue handler");
 718 MODULE_LICENSE("GPL");
 719
 720 module_init(ip6_queue_init);
 721 module_exit(ip6_queue_fini);