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  * 2001-11-06: First try. Working with ip_queue.c for IPv4 and trying
  16  *             to adapt it to IPv6
  17  *             HEAVILY based in ipqueue.c by James Morris. It's just
  18  *             a little modified version of it, so he's nearly the
  19  *             real coder of this.
  20  *             Few changes needed, mainly the hard_routing code and
  21  *             the netlink socket protocol (we're NETLINK_IP6_FW).
  22  * 2002-06-25: Code cleanup. [JM: ported cleanup over from ip_queue.c]
  23  * 2005-02-04: Added /proc counter for dropped packets; fixed so
  24  *             packets aren't delivered to user space if they're going
  25  *             to be dropped.
  26  */
  27 #include <linux/module.h>
  28 #include <linux/skbuff.h>
  29 #include <linux/init.h>
  30 #include <linux/ipv6.h>
  31 #include <linux/notifier.h>
  32 #include <linux/netdevice.h>
  33 #include <linux/netfilter.h>
  34 #include <linux/netlink.h>
  35 #include <linux/spinlock.h>
  36 #include <linux/sysctl.h>
  37 #include <linux/proc_fs.h>
  38 #include <linux/mutex.h>
  39 #include <net/sock.h>
  40 #include <net/ipv6.h>
  41 #include <net/ip6_route.h>
  42 #include <linux/netfilter_ipv4/ip_queue.h>
  43 #include <linux/netfilter_ipv4/ip_tables.h>
  44 #include <linux/netfilter_ipv6/ip6_tables.h>
  45
  46 #define IPQ_QMAX_DEFAULT 1024
  47 #define IPQ_PROC_FS_NAME "ip6_queue"
  48 #define NET_IPQ_QMAX 2088
  49 #define NET_IPQ_QMAX_NAME "ip6_queue_maxlen"
  50
  51 struct ipq_queue_entry {
  52         struct list_head list;
  53         struct nf_info *info;
  54         struct sk_buff *skb;
  55 };
  56
  57 typedef int (*ipq_cmpfn)(struct ipq_queue_entry *, unsigned long);
  58
  59 static unsigned char copy_mode __read_mostly = IPQ_COPY_NONE;
  60 static unsigned int queue_maxlen __read_mostly = IPQ_QMAX_DEFAULT;
  61 static DEFINE_RWLOCK(queue_lock);
  62 static int peer_pid __read_mostly;
  63 static unsigned int copy_range __read_mostly;
  64 static unsigned int queue_total;
  65 static unsigned int queue_dropped = 0;
  66 static unsigned int queue_user_dropped = 0;
  67 static struct sock *ipqnl __read_mostly;
  68 static LIST_HEAD(queue_list);
  69 static DEFINE_MUTEX(ipqnl_mutex);
  70
  71 static void
  72 ipq_issue_verdict(struct ipq_queue_entry *entry, int verdict)
  73 {
  74         local_bh_disable();
  75         nf_reinject(entry->skb, entry->info, verdict);
  76         local_bh_enable();
  77         kfree(entry);
  78 }
  79
  80 static inline void
  81 __ipq_enqueue_entry(struct ipq_queue_entry *entry)
  82 {
  83        list_add(&entry->list, &queue_list);
  84        queue_total++;
  85 }
  86
  87 /*
  88  * Find and return a queued entry matched by cmpfn, or return the last
  89  * entry if cmpfn is NULL.
  90  */
  91 static inline struct ipq_queue_entry *
  92 __ipq_find_entry(ipq_cmpfn cmpfn, unsigned long data)
  93 {
  94         struct list_head *p;
  95
  96         list_for_each_prev(p, &queue_list) {
  97                 struct ipq_queue_entry *entry = (struct ipq_queue_entry *)p;
  98
  99                 if (!cmpfn || cmpfn(entry, data))
 100                         return entry;
 101         }
 102         return NULL;
 103 }
 104
 105 static inline void
 106 __ipq_dequeue_entry(struct ipq_queue_entry *entry)
 107 {
 108         list_del(&entry->list);
 109         queue_total--;
 110 }
 111
 112 static inline struct ipq_queue_entry *
 113 __ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 114 {
 115         struct ipq_queue_entry *entry;
 116
 117         entry = __ipq_find_entry(cmpfn, data);
 118         if (entry == NULL)
 119                 return NULL;
 120
 121         __ipq_dequeue_entry(entry);
 122         return entry;
 123 }
 124
 125
 126 static inline void
 127 __ipq_flush(int verdict)
 128 {
 129         struct ipq_queue_entry *entry;
 130
 131         while ((entry = __ipq_find_dequeue_entry(NULL, 0)))
 132                 ipq_issue_verdict(entry, verdict);
 133 }
 134
 135 static inline int
 136 __ipq_set_mode(unsigned char mode, unsigned int range)
 137 {
 138         int status = 0;
 139
 140         switch(mode) {
 141         case IPQ_COPY_NONE:
 142         case IPQ_COPY_META:
 143                 copy_mode = mode;
 144                 copy_range = 0;
 145                 break;
 146
 147         case IPQ_COPY_PACKET:
 148                 copy_mode = mode;
 149                 copy_range = range;
 150                 if (copy_range > 0xFFFF)
 151                         copy_range = 0xFFFF;
 152                 break;
 153
 154         default:
 155                 status = -EINVAL;
 156
 157         }
 158         return status;
 159 }
 160
 161 static inline void
 162 __ipq_reset(void)
 163 {
 164         peer_pid = 0;
 165         net_disable_timestamp();
 166         __ipq_set_mode(IPQ_COPY_NONE, 0);
 167         __ipq_flush(NF_DROP);
 168 }
 169
 170 static struct ipq_queue_entry *
 171 ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 172 {
 173         struct ipq_queue_entry *entry;
 174
 175         write_lock_bh(&queue_lock);
 176         entry = __ipq_find_dequeue_entry(cmpfn, data);
 177         write_unlock_bh(&queue_lock);
 178         return entry;
 179 }
 180
 181 static void
 182 ipq_flush(int verdict)
 183 {
 184         write_lock_bh(&queue_lock);
 185         __ipq_flush(verdict);
 186         write_unlock_bh(&queue_lock);
 187 }
 188
 189 static struct sk_buff *
 190 ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 191 {
 192         unsigned char *old_tail;
 193         size_t size = 0;
 194         size_t data_len = 0;
 195         struct sk_buff *skb;
 196         struct ipq_packet_msg *pmsg;
 197         struct nlmsghdr *nlh;
 198
 199         read_lock_bh(&queue_lock);
 200
 201         switch (copy_mode) {
 202         case IPQ_COPY_META:
 203         case IPQ_COPY_NONE:
 204                 size = NLMSG_SPACE(sizeof(*pmsg));
 205                 data_len = 0;
 206                 break;
 207
 208         case IPQ_COPY_PACKET:
 209                 if ((entry->skb->ip_summed == CHECKSUM_PARTIAL ||
 210                      entry->skb->ip_summed == CHECKSUM_COMPLETE) &&
 211                     (*errp = skb_checksum_help(entry->skb))) {
 212                         read_unlock_bh(&queue_lock);
 213                         return NULL;
 214                 }
 215                 if (copy_range == 0 || copy_range > entry->skb->len)
 216                         data_len = entry->skb->len;
 217                 else
 218                         data_len = copy_range;
 219
 220                 size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
 221                 break;
 222
 223         default:
 224                 *errp = -EINVAL;
 225                 read_unlock_bh(&queue_lock);
 226                 return NULL;
 227         }
 228
 229         read_unlock_bh(&queue_lock);
 230
 231         skb = alloc_skb(size, GFP_ATOMIC);
 232         if (!skb)
 233                 goto nlmsg_failure;
 234
 235         old_tail= skb->tail;
 236         nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
 237         pmsg = NLMSG_DATA(nlh);
 238         memset(pmsg, 0, sizeof(*pmsg));
 239
 240         pmsg->packet_id       = (unsigned long )entry;
 241         pmsg->data_len        = data_len;
 242         pmsg->timestamp_sec   = entry->skb->tstamp.off_sec;
 243         pmsg->timestamp_usec  = entry->skb->tstamp.off_usec;
 244         pmsg->mark            = entry->skb->mark;
 245         pmsg->hook            = entry->info->hook;
 246         pmsg->hw_protocol     = entry->skb->protocol;
 247
 248         if (entry->info->indev)
 249                 strcpy(pmsg->indev_name, entry->info->indev->name);
 250         else
 251                 pmsg->indev_name[0] = '\0';
 252
 253         if (entry->info->outdev)
 254                 strcpy(pmsg->outdev_name, entry->info->outdev->name);
 255         else
 256                 pmsg->outdev_name[0] = '\0';
 257
 258         if (entry->info->indev && entry->skb->dev) {
 259                 pmsg->hw_type = entry->skb->dev->type;
 260                 if (entry->skb->dev->hard_header_parse)
 261                         pmsg->hw_addrlen =
 262                                 entry->skb->dev->hard_header_parse(entry->skb,
 263                                                                    pmsg->hw_addr);
 264         }
 265
 266         if (data_len)
 267                 if (skb_copy_bits(entry->skb, 0, pmsg->payload, data_len))
 268                         BUG();
 269
 270         nlh->nlmsg_len = skb->tail - old_tail;
 271         return skb;
 272
 273 nlmsg_failure:
 274         if (skb)
 275                 kfree_skb(skb);
 276         *errp = -EINVAL;
 277         printk(KERN_ERR "ip6_queue: error creating packet message\n");
 278         return NULL;
 279 }
 280
 281 static int
 282 ipq_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
 283                    unsigned int queuenum, void *data)
 284 {
 285         int status = -EINVAL;
 286         struct sk_buff *nskb;
 287         struct ipq_queue_entry *entry;
 288
 289         if (copy_mode == IPQ_COPY_NONE)
 290                 return -EAGAIN;
 291
 292         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 293         if (entry == NULL) {
 294                 printk(KERN_ERR "ip6_queue: OOM in ipq_enqueue_packet()\n");
 295                 return -ENOMEM;
 296         }
 297
 298         entry->info = info;
 299         entry->skb = skb;
 300
 301         nskb = ipq_build_packet_message(entry, &status);
 302         if (nskb == NULL)
 303                 goto err_out_free;
 304
 305         write_lock_bh(&queue_lock);
 306
 307         if (!peer_pid)
 308                 goto err_out_free_nskb;
 309
 310         if (queue_total >= queue_maxlen) {
 311                 queue_dropped++;
 312                 status = -ENOSPC;
 313                 if (net_ratelimit())
 314                         printk (KERN_WARNING "ip6_queue: fill at %d entries, "
 315                                 "dropping packet(s).  Dropped: %d\n", queue_total,
 316                                 queue_dropped);
 317                 goto err_out_free_nskb;
 318         }
 319
 320         /* netlink_unicast will either free the nskb or attach it to a socket */
 321         status = netlink_unicast(ipqnl, nskb, peer_pid, MSG_DONTWAIT);
 322         if (status < 0) {
 323                 queue_user_dropped++;
 324                 goto err_out_unlock;
 325         }
 326
 327         __ipq_enqueue_entry(entry);
 328
 329         write_unlock_bh(&queue_lock);
 330         return status;
 331
 332 err_out_free_nskb:
 333         kfree_skb(nskb);
 334
 335 err_out_unlock:
 336         write_unlock_bh(&queue_lock);
 337
 338 err_out_free:
 339         kfree(entry);
 340         return status;
 341 }
 342
 343 static int
 344 ipq_mangle_ipv6(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
 345 {
 346         int diff;
 347         struct ipv6hdr *user_iph = (struct ipv6hdr *)v->payload;
 348
 349         if (v->data_len < sizeof(*user_iph))
 350                 return 0;
 351         diff = v->data_len - e->skb->len;
 352         if (diff < 0) {
 353                 if (pskb_trim(e->skb, v->data_len))
 354                         return -ENOMEM;
 355         } else if (diff > 0) {
 356                 if (v->data_len > 0xFFFF)
 357                         return -EINVAL;
 358                 if (diff > skb_tailroom(e->skb)) {
 359                         struct sk_buff *newskb;
 360
 361                         newskb = skb_copy_expand(e->skb,
 362                                                  skb_headroom(e->skb),
 363                                                  diff,
 364                                                  GFP_ATOMIC);
 365                         if (newskb == NULL) {
 366                                 printk(KERN_WARNING "ip6_queue: OOM "
 367                                       "in mangle, dropping packet\n");
 368                                 return -ENOMEM;
 369                         }
 370                         if (e->skb->sk)
 371                                 skb_set_owner_w(newskb, e->skb->sk);
 372                         kfree_skb(e->skb);
 373                         e->skb = newskb;
 374                 }
 375                 skb_put(e->skb, diff);
 376         }
 377         if (!skb_make_writable(&e->skb, v->data_len))
 378                 return -ENOMEM;
 379         memcpy(e->skb->data, v->payload, v->data_len);
 380         e->skb->ip_summed = CHECKSUM_NONE;
 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 (security_netlink_recv(skb, 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         } else {
 520                 net_enable_timestamp();
 521                 peer_pid = pid;
 522         }
 523
 524         write_unlock_bh(&queue_lock);
 525
 526         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 527                                   nlmsglen - NLMSG_LENGTH(0));
 528         if (status < 0)
 529                 RCV_SKB_FAIL(status);
 530
 531         if (flags & NLM_F_ACK)
 532                 netlink_ack(skb, nlh, 0);
 533         return;
 534 }
 535
 536 static void
 537 ipq_rcv_sk(struct sock *sk, int len)
 538 {
 539         struct sk_buff *skb;
 540         unsigned int qlen;
 541
 542         mutex_lock(&ipqnl_mutex);
 543
 544         for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
 545                 skb = skb_dequeue(&sk->sk_receive_queue);
 546                 ipq_rcv_skb(skb);
 547                 kfree_skb(skb);
 548         }
 549
 550         mutex_unlock(&ipqnl_mutex);
 551 }
 552
 553 static int
 554 ipq_rcv_dev_event(struct notifier_block *this,
 555                   unsigned long event, void *ptr)
 556 {
 557         struct net_device *dev = ptr;
 558
 559         /* Drop any packets associated with the downed device */
 560         if (event == NETDEV_DOWN)
 561                 ipq_dev_drop(dev->ifindex);
 562         return NOTIFY_DONE;
 563 }
 564
 565 static struct notifier_block ipq_dev_notifier = {
 566         .notifier_call  = ipq_rcv_dev_event,
 567 };
 568
 569 static int
 570 ipq_rcv_nl_event(struct notifier_block *this,
 571                  unsigned long event, void *ptr)
 572 {
 573         struct netlink_notify *n = ptr;
 574
 575         if (event == NETLINK_URELEASE &&
 576             n->protocol == NETLINK_IP6_FW && n->pid) {
 577                 write_lock_bh(&queue_lock);
 578                 if (n->pid == peer_pid)
 579                         __ipq_reset();
 580                 write_unlock_bh(&queue_lock);
 581         }
 582         return NOTIFY_DONE;
 583 }
 584
 585 static struct notifier_block ipq_nl_notifier = {
 586         .notifier_call  = ipq_rcv_nl_event,
 587 };
 588
 589 static struct ctl_table_header *ipq_sysctl_header;
 590
 591 static ctl_table ipq_table[] = {
 592         {
 593                 .ctl_name       = NET_IPQ_QMAX,
 594                 .procname       = NET_IPQ_QMAX_NAME,
 595                 .data           = &queue_maxlen,
 596                 .maxlen         = sizeof(queue_maxlen),
 597                 .mode           = 0644,
 598                 .proc_handler   = proc_dointvec
 599         },
 600         { .ctl_name = 0 }
 601 };
 602
 603 static ctl_table ipq_dir_table[] = {
 604         {
 605                 .ctl_name       = NET_IPV6,
 606                 .procname       = "ipv6",
 607                 .mode           = 0555,
 608                 .child          = ipq_table
 609         },
 610         { .ctl_name = 0 }
 611 };
 612
 613 static ctl_table ipq_root_table[] = {
 614         {
 615                 .ctl_name       = CTL_NET,
 616                 .procname       = "net",
 617                 .mode           = 0555,
 618                 .child          = ipq_dir_table
 619         },
 620         { .ctl_name = 0 }
 621 };
 622
 623 #ifdef CONFIG_PROC_FS
 624 static int
 625 ipq_get_info(char *buffer, char **start, off_t offset, int length)
 626 {
 627         int len;
 628
 629         read_lock_bh(&queue_lock);
 630
 631         len = sprintf(buffer,
 632                       "Peer PID          : %d\n"
 633                       "Copy mode         : %hu\n"
 634                       "Copy range        : %u\n"
 635                       "Queue length      : %u\n"
 636                       "Queue max. length : %u\n"
 637                       "Queue dropped     : %u\n"
 638                       "Netfilter dropped : %u\n",
 639                       peer_pid,
 640                       copy_mode,
 641                       copy_range,
 642                       queue_total,
 643                       queue_maxlen,
 644                       queue_dropped,
 645                       queue_user_dropped);
 646
 647         read_unlock_bh(&queue_lock);
 648
 649         *start = buffer + offset;
 650         len -= offset;
 651         if (len > length)
 652                 len = length;
 653         else if (len < 0)
 654                 len = 0;
 655         return len;
 656 }
 657 #endif /* CONFIG_PROC_FS */
 658
 659 static struct nf_queue_handler nfqh = {
 660         .name   = "ip6_queue",
 661         .outfn  = &ipq_enqueue_packet,
 662 };
 663
 664 static int __init ip6_queue_init(void)
 665 {
 666         int status = -ENOMEM;
 667         struct proc_dir_entry *proc;
 668
 669         netlink_register_notifier(&ipq_nl_notifier);
 670         ipqnl = netlink_kernel_create(NETLINK_IP6_FW, 0, ipq_rcv_sk,
 671                                       THIS_MODULE);
 672         if (ipqnl == NULL) {
 673                 printk(KERN_ERR "ip6_queue: failed to create netlink socket\n");
 674                 goto cleanup_netlink_notifier;
 675         }
 676
 677         proc = proc_net_create(IPQ_PROC_FS_NAME, 0, ipq_get_info);
 678         if (proc)
 679                 proc->owner = THIS_MODULE;
 680         else {
 681                 printk(KERN_ERR "ip6_queue: failed to create proc entry\n");
 682                 goto cleanup_ipqnl;
 683         }
 684
 685         register_netdevice_notifier(&ipq_dev_notifier);
 686         ipq_sysctl_header = register_sysctl_table(ipq_root_table);
 687
 688         status = nf_register_queue_handler(PF_INET6, &nfqh);
 689         if (status < 0) {
 690                 printk(KERN_ERR "ip6_queue: failed to register queue handler\n");
 691                 goto cleanup_sysctl;
 692         }
 693         return status;
 694
 695 cleanup_sysctl:
 696         unregister_sysctl_table(ipq_sysctl_header);
 697         unregister_netdevice_notifier(&ipq_dev_notifier);
 698         proc_net_remove(IPQ_PROC_FS_NAME);
 699
 700 cleanup_ipqnl:
 701         sock_release(ipqnl->sk_socket);
 702         mutex_lock(&ipqnl_mutex);
 703         mutex_unlock(&ipqnl_mutex);
 704
 705 cleanup_netlink_notifier:
 706         netlink_unregister_notifier(&ipq_nl_notifier);
 707         return status;
 708 }
 709
 710 static void __exit ip6_queue_fini(void)
 711 {
 712         nf_unregister_queue_handlers(&nfqh);
 713         synchronize_net();
 714         ipq_flush(NF_DROP);
 715
 716         unregister_sysctl_table(ipq_sysctl_header);
 717         unregister_netdevice_notifier(&ipq_dev_notifier);
 718         proc_net_remove(IPQ_PROC_FS_NAME);
 719
 720         sock_release(ipqnl->sk_socket);
 721         mutex_lock(&ipqnl_mutex);
 722         mutex_unlock(&ipqnl_mutex);
 723
 724         netlink_unregister_notifier(&ipq_nl_notifier);
 725 }
 726
 727 MODULE_DESCRIPTION("IPv6 packet queue handler");
 728 MODULE_LICENSE("GPL");
 729
 730 module_init(ip6_queue_init);
 731 module_exit(ip6_queue_fini);