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         sk_buff_data_t 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         struct timeval tv;
 199
 200         read_lock_bh(&queue_lock);
 201
 202         switch (copy_mode) {
 203         case IPQ_COPY_META:
 204         case IPQ_COPY_NONE:
 205                 size = NLMSG_SPACE(sizeof(*pmsg));
 206                 data_len = 0;
 207                 break;
 208
 209         case IPQ_COPY_PACKET:
 210                 if ((entry->skb->ip_summed == CHECKSUM_PARTIAL ||
 211                      entry->skb->ip_summed == CHECKSUM_COMPLETE) &&
 212                     (*errp = skb_checksum_help(entry->skb))) {
 213                         read_unlock_bh(&queue_lock);
 214                         return NULL;
 215                 }
 216                 if (copy_range == 0 || copy_range > entry->skb->len)
 217                         data_len = entry->skb->len;
 218                 else
 219                         data_len = copy_range;
 220
 221                 size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
 222                 break;
 223
 224         default:
 225                 *errp = -EINVAL;
 226                 read_unlock_bh(&queue_lock);
 227                 return NULL;
 228         }
 229
 230         read_unlock_bh(&queue_lock);
 231
 232         skb = alloc_skb(size, GFP_ATOMIC);
 233         if (!skb)
 234                 goto nlmsg_failure;
 235
 236         old_tail = skb->tail;
 237         nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
 238         pmsg = NLMSG_DATA(nlh);
 239         memset(pmsg, 0, sizeof(*pmsg));
 240
 241         pmsg->packet_id       = (unsigned long )entry;
 242         pmsg->data_len        = data_len;
 243         tv = ktime_to_timeval(entry->skb->tstamp);
 244         pmsg->timestamp_sec   = tv.tv_sec;
 245         pmsg->timestamp_usec  = tv.tv_usec;
 246         pmsg->mark            = entry->skb->mark;
 247         pmsg->hook            = entry->info->hook;
 248         pmsg->hw_protocol     = entry->skb->protocol;
 249
 250         if (entry->info->indev)
 251                 strcpy(pmsg->indev_name, entry->info->indev->name);
 252         else
 253                 pmsg->indev_name[0] = '\0';
 254
 255         if (entry->info->outdev)
 256                 strcpy(pmsg->outdev_name, entry->info->outdev->name);
 257         else
 258                 pmsg->outdev_name[0] = '\0';
 259
 260         if (entry->info->indev && entry->skb->dev) {
 261                 pmsg->hw_type = entry->skb->dev->type;
 262                 if (entry->skb->dev->hard_header_parse)
 263                         pmsg->hw_addrlen =
 264                                 entry->skb->dev->hard_header_parse(entry->skb,
 265                                                                    pmsg->hw_addr);
 266         }
 267
 268         if (data_len)
 269                 if (skb_copy_bits(entry->skb, 0, pmsg->payload, data_len))
 270                         BUG();
 271
 272         nlh->nlmsg_len = skb->tail - old_tail;
 273         return skb;
 274
 275 nlmsg_failure:
 276         if (skb)
 277                 kfree_skb(skb);
 278         *errp = -EINVAL;
 279         printk(KERN_ERR "ip6_queue: error creating packet message\n");
 280         return NULL;
 281 }
 282
 283 static int
 284 ipq_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
 285                    unsigned int queuenum, void *data)
 286 {
 287         int status = -EINVAL;
 288         struct sk_buff *nskb;
 289         struct ipq_queue_entry *entry;
 290
 291         if (copy_mode == IPQ_COPY_NONE)
 292                 return -EAGAIN;
 293
 294         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 295         if (entry == NULL) {
 296                 printk(KERN_ERR "ip6_queue: OOM in ipq_enqueue_packet()\n");
 297                 return -ENOMEM;
 298         }
 299
 300         entry->info = info;
 301         entry->skb = skb;
 302
 303         nskb = ipq_build_packet_message(entry, &status);
 304         if (nskb == NULL)
 305                 goto err_out_free;
 306
 307         write_lock_bh(&queue_lock);
 308
 309         if (!peer_pid)
 310                 goto err_out_free_nskb;
 311
 312         if (queue_total >= queue_maxlen) {
 313                 queue_dropped++;
 314                 status = -ENOSPC;
 315                 if (net_ratelimit())
 316                         printk (KERN_WARNING "ip6_queue: fill at %d entries, "
 317                                 "dropping packet(s).  Dropped: %d\n", queue_total,
 318                                 queue_dropped);
 319                 goto err_out_free_nskb;
 320         }
 321
 322         /* netlink_unicast will either free the nskb or attach it to a socket */
 323         status = netlink_unicast(ipqnl, nskb, peer_pid, MSG_DONTWAIT);
 324         if (status < 0) {
 325                 queue_user_dropped++;
 326                 goto err_out_unlock;
 327         }
 328
 329         __ipq_enqueue_entry(entry);
 330
 331         write_unlock_bh(&queue_lock);
 332         return status;
 333
 334 err_out_free_nskb:
 335         kfree_skb(nskb);
 336
 337 err_out_unlock:
 338         write_unlock_bh(&queue_lock);
 339
 340 err_out_free:
 341         kfree(entry);
 342         return status;
 343 }
 344
 345 static int
 346 ipq_mangle_ipv6(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
 347 {
 348         int diff;
 349         struct ipv6hdr *user_iph = (struct ipv6hdr *)v->payload;
 350
 351         if (v->data_len < sizeof(*user_iph))
 352                 return 0;
 353         diff = v->data_len - e->skb->len;
 354         if (diff < 0) {
 355                 if (pskb_trim(e->skb, v->data_len))
 356                         return -ENOMEM;
 357         } else if (diff > 0) {
 358                 if (v->data_len > 0xFFFF)
 359                         return -EINVAL;
 360                 if (diff > skb_tailroom(e->skb)) {
 361                         struct sk_buff *newskb;
 362
 363                         newskb = skb_copy_expand(e->skb,
 364                                                  skb_headroom(e->skb),
 365                                                  diff,
 366                                                  GFP_ATOMIC);
 367                         if (newskb == NULL) {
 368                                 printk(KERN_WARNING "ip6_queue: OOM "
 369                                       "in mangle, dropping packet\n");
 370                                 return -ENOMEM;
 371                         }
 372                         if (e->skb->sk)
 373                                 skb_set_owner_w(newskb, e->skb->sk);
 374                         kfree_skb(e->skb);
 375                         e->skb = newskb;
 376                 }
 377                 skb_put(e->skb, diff);
 378         }
 379         if (!skb_make_writable(&e->skb, v->data_len))
 380                 return -ENOMEM;
 381         memcpy(e->skb->data, v->payload, v->data_len);
 382         e->skb->ip_summed = CHECKSUM_NONE;
 383
 384         return 0;
 385 }
 386
 387 static inline int
 388 id_cmp(struct ipq_queue_entry *e, unsigned long id)
 389 {
 390         return (id == (unsigned long )e);
 391 }
 392
 393 static int
 394 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
 395 {
 396         struct ipq_queue_entry *entry;
 397
 398         if (vmsg->value > NF_MAX_VERDICT)
 399                 return -EINVAL;
 400
 401         entry = ipq_find_dequeue_entry(id_cmp, vmsg->id);
 402         if (entry == NULL)
 403                 return -ENOENT;
 404         else {
 405                 int verdict = vmsg->value;
 406
 407                 if (vmsg->data_len && vmsg->data_len == len)
 408                         if (ipq_mangle_ipv6(vmsg, entry) < 0)
 409                                 verdict = NF_DROP;
 410
 411                 ipq_issue_verdict(entry, verdict);
 412                 return 0;
 413         }
 414 }
 415
 416 static int
 417 ipq_set_mode(unsigned char mode, unsigned int range)
 418 {
 419         int status;
 420
 421         write_lock_bh(&queue_lock);
 422         status = __ipq_set_mode(mode, range);
 423         write_unlock_bh(&queue_lock);
 424         return status;
 425 }
 426
 427 static int
 428 ipq_receive_peer(struct ipq_peer_msg *pmsg,
 429                  unsigned char type, unsigned int len)
 430 {
 431         int status = 0;
 432
 433         if (len < sizeof(*pmsg))
 434                 return -EINVAL;
 435
 436         switch (type) {
 437         case IPQM_MODE:
 438                 status = ipq_set_mode(pmsg->msg.mode.value,
 439                                       pmsg->msg.mode.range);
 440                 break;
 441
 442         case IPQM_VERDICT:
 443                 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
 444                         status = -EINVAL;
 445                 else
 446                         status = ipq_set_verdict(&pmsg->msg.verdict,
 447                                                  len - sizeof(*pmsg));
 448                         break;
 449         default:
 450                 status = -EINVAL;
 451         }
 452         return status;
 453 }
 454
 455 static int
 456 dev_cmp(struct ipq_queue_entry *entry, unsigned long ifindex)
 457 {
 458         if (entry->info->indev)
 459                 if (entry->info->indev->ifindex == ifindex)
 460                         return 1;
 461
 462         if (entry->info->outdev)
 463                 if (entry->info->outdev->ifindex == ifindex)
 464                         return 1;
 465
 466         return 0;
 467 }
 468
 469 static void
 470 ipq_dev_drop(int ifindex)
 471 {
 472         struct ipq_queue_entry *entry;
 473
 474         while ((entry = ipq_find_dequeue_entry(dev_cmp, ifindex)) != NULL)
 475                 ipq_issue_verdict(entry, NF_DROP);
 476 }
 477
 478 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 479
 480 static inline void
 481 ipq_rcv_skb(struct sk_buff *skb)
 482 {
 483         int status, type, pid, flags, nlmsglen, skblen;
 484         struct nlmsghdr *nlh;
 485
 486         skblen = skb->len;
 487         if (skblen < sizeof(*nlh))
 488                 return;
 489
 490         nlh = nlmsg_hdr(skb);
 491         nlmsglen = nlh->nlmsg_len;
 492         if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
 493                 return;
 494
 495         pid = nlh->nlmsg_pid;
 496         flags = nlh->nlmsg_flags;
 497
 498         if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
 499                 RCV_SKB_FAIL(-EINVAL);
 500
 501         if (flags & MSG_TRUNC)
 502                 RCV_SKB_FAIL(-ECOMM);
 503
 504         type = nlh->nlmsg_type;
 505         if (type < NLMSG_NOOP || type >= IPQM_MAX)
 506                 RCV_SKB_FAIL(-EINVAL);
 507
 508         if (type <= IPQM_BASE)
 509                 return;
 510
 511         if (security_netlink_recv(skb, CAP_NET_ADMIN))
 512                 RCV_SKB_FAIL(-EPERM);
 513
 514         write_lock_bh(&queue_lock);
 515
 516         if (peer_pid) {
 517                 if (peer_pid != pid) {
 518                         write_unlock_bh(&queue_lock);
 519                         RCV_SKB_FAIL(-EBUSY);
 520                 }
 521         } else {
 522                 net_enable_timestamp();
 523                 peer_pid = pid;
 524         }
 525
 526         write_unlock_bh(&queue_lock);
 527
 528         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 529                                   nlmsglen - NLMSG_LENGTH(0));
 530         if (status < 0)
 531                 RCV_SKB_FAIL(status);
 532
 533         if (flags & NLM_F_ACK)
 534                 netlink_ack(skb, nlh, 0);
 535         return;
 536 }
 537
 538 static void
 539 ipq_rcv_sk(struct sock *sk, int len)
 540 {
 541         struct sk_buff *skb;
 542         unsigned int qlen;
 543
 544         mutex_lock(&ipqnl_mutex);
 545
 546         for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
 547                 skb = skb_dequeue(&sk->sk_receive_queue);
 548                 ipq_rcv_skb(skb);
 549                 kfree_skb(skb);
 550         }
 551
 552         mutex_unlock(&ipqnl_mutex);
 553 }
 554
 555 static int
 556 ipq_rcv_dev_event(struct notifier_block *this,
 557                   unsigned long event, void *ptr)
 558 {
 559         struct net_device *dev = ptr;
 560
 561         /* Drop any packets associated with the downed device */
 562         if (event == NETDEV_DOWN)
 563                 ipq_dev_drop(dev->ifindex);
 564         return NOTIFY_DONE;
 565 }
 566
 567 static struct notifier_block ipq_dev_notifier = {
 568         .notifier_call  = ipq_rcv_dev_event,
 569 };
 570
 571 static int
 572 ipq_rcv_nl_event(struct notifier_block *this,
 573                  unsigned long event, void *ptr)
 574 {
 575         struct netlink_notify *n = ptr;
 576
 577         if (event == NETLINK_URELEASE &&
 578             n->protocol == NETLINK_IP6_FW && n->pid) {
 579                 write_lock_bh(&queue_lock);
 580                 if (n->pid == peer_pid)
 581                         __ipq_reset();
 582                 write_unlock_bh(&queue_lock);
 583         }
 584         return NOTIFY_DONE;
 585 }
 586
 587 static struct notifier_block ipq_nl_notifier = {
 588         .notifier_call  = ipq_rcv_nl_event,
 589 };
 590
 591 static struct ctl_table_header *ipq_sysctl_header;
 592
 593 static ctl_table ipq_table[] = {
 594         {
 595                 .ctl_name       = NET_IPQ_QMAX,
 596                 .procname       = NET_IPQ_QMAX_NAME,
 597                 .data           = &queue_maxlen,
 598                 .maxlen         = sizeof(queue_maxlen),
 599                 .mode           = 0644,
 600                 .proc_handler   = proc_dointvec
 601         },
 602         { .ctl_name = 0 }
 603 };
 604
 605 static ctl_table ipq_dir_table[] = {
 606         {
 607                 .ctl_name       = NET_IPV6,
 608                 .procname       = "ipv6",
 609                 .mode           = 0555,
 610                 .child          = ipq_table
 611         },
 612         { .ctl_name = 0 }
 613 };
 614
 615 static ctl_table ipq_root_table[] = {
 616         {
 617                 .ctl_name       = CTL_NET,
 618                 .procname       = "net",
 619                 .mode           = 0555,
 620                 .child          = ipq_dir_table
 621         },
 622         { .ctl_name = 0 }
 623 };
 624
 625 #ifdef CONFIG_PROC_FS
 626 static int
 627 ipq_get_info(char *buffer, char **start, off_t offset, int length)
 628 {
 629         int len;
 630
 631         read_lock_bh(&queue_lock);
 632
 633         len = sprintf(buffer,
 634                       "Peer PID          : %d\n"
 635                       "Copy mode         : %hu\n"
 636                       "Copy range        : %u\n"
 637                       "Queue length      : %u\n"
 638                       "Queue max. length : %u\n"
 639                       "Queue dropped     : %u\n"
 640                       "Netfilter dropped : %u\n",
 641                       peer_pid,
 642                       copy_mode,
 643                       copy_range,
 644                       queue_total,
 645                       queue_maxlen,
 646                       queue_dropped,
 647                       queue_user_dropped);
 648
 649         read_unlock_bh(&queue_lock);
 650
 651         *start = buffer + offset;
 652         len -= offset;
 653         if (len > length)
 654                 len = length;
 655         else if (len < 0)
 656                 len = 0;
 657         return len;
 658 }
 659 #endif /* CONFIG_PROC_FS */
 660
 661 static struct nf_queue_handler nfqh = {
 662         .name   = "ip6_queue",
 663         .outfn  = &ipq_enqueue_packet,
 664 };
 665
 666 static int __init ip6_queue_init(void)
 667 {
 668         int status = -ENOMEM;
 669         struct proc_dir_entry *proc;
 670
 671         netlink_register_notifier(&ipq_nl_notifier);
 672         ipqnl = netlink_kernel_create(NETLINK_IP6_FW, 0, ipq_rcv_sk,
 673                                       THIS_MODULE);
 674         if (ipqnl == NULL) {
 675                 printk(KERN_ERR "ip6_queue: failed to create netlink socket\n");
 676                 goto cleanup_netlink_notifier;
 677         }
 678
 679         proc = proc_net_create(IPQ_PROC_FS_NAME, 0, ipq_get_info);
 680         if (proc)
 681                 proc->owner = THIS_MODULE;
 682         else {
 683                 printk(KERN_ERR "ip6_queue: failed to create proc entry\n");
 684                 goto cleanup_ipqnl;
 685         }
 686
 687         register_netdevice_notifier(&ipq_dev_notifier);
 688         ipq_sysctl_header = register_sysctl_table(ipq_root_table);
 689
 690         status = nf_register_queue_handler(PF_INET6, &nfqh);
 691         if (status < 0) {
 692                 printk(KERN_ERR "ip6_queue: failed to register queue handler\n");
 693                 goto cleanup_sysctl;
 694         }
 695         return status;
 696
 697 cleanup_sysctl:
 698         unregister_sysctl_table(ipq_sysctl_header);
 699         unregister_netdevice_notifier(&ipq_dev_notifier);
 700         proc_net_remove(IPQ_PROC_FS_NAME);
 701
 702 cleanup_ipqnl:
 703         sock_release(ipqnl->sk_socket);
 704         mutex_lock(&ipqnl_mutex);
 705         mutex_unlock(&ipqnl_mutex);
 706
 707 cleanup_netlink_notifier:
 708         netlink_unregister_notifier(&ipq_nl_notifier);
 709         return status;
 710 }
 711
 712 static void __exit ip6_queue_fini(void)
 713 {
 714         nf_unregister_queue_handlers(&nfqh);
 715         synchronize_net();
 716         ipq_flush(NF_DROP);
 717
 718         unregister_sysctl_table(ipq_sysctl_header);
 719         unregister_netdevice_notifier(&ipq_dev_notifier);
 720         proc_net_remove(IPQ_PROC_FS_NAME);
 721
 722         sock_release(ipqnl->sk_socket);
 723         mutex_lock(&ipqnl_mutex);
 724         mutex_unlock(&ipqnl_mutex);
 725
 726         netlink_unregister_notifier(&ipq_nl_notifier);
 727 }
 728
 729 MODULE_DESCRIPTION("IPv6 packet queue handler");
 730 MODULE_LICENSE("GPL");
 731
 732 module_init(ip6_queue_init);
 733 module_exit(ip6_queue_fini);