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 = IPQ_COPY_NONE;
  60 static unsigned int queue_maxlen = IPQ_QMAX_DEFAULT;
  61 static DEFINE_RWLOCK(queue_lock);
  62 static int peer_pid;
  63 static unsigned int copy_range;
  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;
  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_HW &&
 210                     (*errp = skb_checksum_help(entry->skb,
 211                                                entry->info->outdev == NULL))) {
 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->nfmark;
 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                 skb_trim(e->skb, v->data_len);
 354         else if (diff > 0) {
 355                 if (v->data_len > 0xFFFF)
 356                         return -EINVAL;
 357                 if (diff > skb_tailroom(e->skb)) {
 358                         struct sk_buff *newskb;
 359
 360                         newskb = skb_copy_expand(e->skb,
 361                                                  skb_headroom(e->skb),
 362                                                  diff,
 363                                                  GFP_ATOMIC);
 364                         if (newskb == NULL) {
 365                                 printk(KERN_WARNING "ip6_queue: OOM "
 366                                       "in mangle, dropping packet\n");
 367                                 return -ENOMEM;
 368                         }
 369                         if (e->skb->sk)
 370                                 skb_set_owner_w(newskb, e->skb->sk);
 371                         kfree_skb(e->skb);
 372                         e->skb = newskb;
 373                 }
 374                 skb_put(e->skb, diff);
 375         }
 376         if (!skb_make_writable(&e->skb, v->data_len))
 377                 return -ENOMEM;
 378         memcpy(e->skb->data, v->payload, v->data_len);
 379         e->skb->ip_summed = CHECKSUM_NONE;
 380
 381         return 0;
 382 }
 383
 384 static inline int
 385 id_cmp(struct ipq_queue_entry *e, unsigned long id)
 386 {
 387         return (id == (unsigned long )e);
 388 }
 389
 390 static int
 391 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
 392 {
 393         struct ipq_queue_entry *entry;
 394
 395         if (vmsg->value > NF_MAX_VERDICT)
 396                 return -EINVAL;
 397
 398         entry = ipq_find_dequeue_entry(id_cmp, vmsg->id);
 399         if (entry == NULL)
 400                 return -ENOENT;
 401         else {
 402                 int verdict = vmsg->value;
 403
 404                 if (vmsg->data_len && vmsg->data_len == len)
 405                         if (ipq_mangle_ipv6(vmsg, entry) < 0)
 406                                 verdict = NF_DROP;
 407
 408                 ipq_issue_verdict(entry, verdict);
 409                 return 0;
 410         }
 411 }
 412
 413 static int
 414 ipq_set_mode(unsigned char mode, unsigned int range)
 415 {
 416         int status;
 417
 418         write_lock_bh(&queue_lock);
 419         status = __ipq_set_mode(mode, range);
 420         write_unlock_bh(&queue_lock);
 421         return status;
 422 }
 423
 424 static int
 425 ipq_receive_peer(struct ipq_peer_msg *pmsg,
 426                  unsigned char type, unsigned int len)
 427 {
 428         int status = 0;
 429
 430         if (len < sizeof(*pmsg))
 431                 return -EINVAL;
 432
 433         switch (type) {
 434         case IPQM_MODE:
 435                 status = ipq_set_mode(pmsg->msg.mode.value,
 436                                       pmsg->msg.mode.range);
 437                 break;
 438
 439         case IPQM_VERDICT:
 440                 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
 441                         status = -EINVAL;
 442                 else
 443                         status = ipq_set_verdict(&pmsg->msg.verdict,
 444                                                  len - sizeof(*pmsg));
 445                         break;
 446         default:
 447                 status = -EINVAL;
 448         }
 449         return status;
 450 }
 451
 452 static int
 453 dev_cmp(struct ipq_queue_entry *entry, unsigned long ifindex)
 454 {
 455         if (entry->info->indev)
 456                 if (entry->info->indev->ifindex == ifindex)
 457                         return 1;
 458
 459         if (entry->info->outdev)
 460                 if (entry->info->outdev->ifindex == ifindex)
 461                         return 1;
 462
 463         return 0;
 464 }
 465
 466 static void
 467 ipq_dev_drop(int ifindex)
 468 {
 469         struct ipq_queue_entry *entry;
 470
 471         while ((entry = ipq_find_dequeue_entry(dev_cmp, ifindex)) != NULL)
 472                 ipq_issue_verdict(entry, NF_DROP);
 473 }
 474
 475 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 476
 477 static inline void
 478 ipq_rcv_skb(struct sk_buff *skb)
 479 {
 480         int status, type, pid, flags, nlmsglen, skblen;
 481         struct nlmsghdr *nlh;
 482
 483         skblen = skb->len;
 484         if (skblen < sizeof(*nlh))
 485                 return;
 486
 487         nlh = (struct nlmsghdr *)skb->data;
 488         nlmsglen = nlh->nlmsg_len;
 489         if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
 490                 return;
 491
 492         pid = nlh->nlmsg_pid;
 493         flags = nlh->nlmsg_flags;
 494
 495         if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
 496                 RCV_SKB_FAIL(-EINVAL);
 497
 498         if (flags & MSG_TRUNC)
 499                 RCV_SKB_FAIL(-ECOMM);
 500
 501         type = nlh->nlmsg_type;
 502         if (type < NLMSG_NOOP || type >= IPQM_MAX)
 503                 RCV_SKB_FAIL(-EINVAL);
 504
 505         if (type <= IPQM_BASE)
 506                 return;
 507
 508         if (security_netlink_recv(skb))
 509                 RCV_SKB_FAIL(-EPERM);
 510
 511         write_lock_bh(&queue_lock);
 512
 513         if (peer_pid) {
 514                 if (peer_pid != pid) {
 515                         write_unlock_bh(&queue_lock);
 516                         RCV_SKB_FAIL(-EBUSY);
 517                 }
 518         } else {
 519                 net_enable_timestamp();
 520                 peer_pid = pid;
 521         }
 522
 523         write_unlock_bh(&queue_lock);
 524
 525         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 526                                   nlmsglen - NLMSG_LENGTH(0));
 527         if (status < 0)
 528                 RCV_SKB_FAIL(status);
 529
 530         if (flags & NLM_F_ACK)
 531                 netlink_ack(skb, nlh, 0);
 532         return;
 533 }
 534
 535 static void
 536 ipq_rcv_sk(struct sock *sk, int len)
 537 {
 538         struct sk_buff *skb;
 539         unsigned int qlen;
 540
 541         mutex_lock(&ipqnl_mutex);
 542
 543         for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
 544                 skb = skb_dequeue(&sk->sk_receive_queue);
 545                 ipq_rcv_skb(skb);
 546                 kfree_skb(skb);
 547         }
 548
 549         mutex_unlock(&ipqnl_mutex);
 550 }
 551
 552 static int
 553 ipq_rcv_dev_event(struct notifier_block *this,
 554                   unsigned long event, void *ptr)
 555 {
 556         struct net_device *dev = ptr;
 557
 558         /* Drop any packets associated with the downed device */
 559         if (event == NETDEV_DOWN)
 560                 ipq_dev_drop(dev->ifindex);
 561         return NOTIFY_DONE;
 562 }
 563
 564 static struct notifier_block ipq_dev_notifier = {
 565         .notifier_call  = ipq_rcv_dev_event,
 566 };
 567
 568 static int
 569 ipq_rcv_nl_event(struct notifier_block *this,
 570                  unsigned long event, void *ptr)
 571 {
 572         struct netlink_notify *n = ptr;
 573
 574         if (event == NETLINK_URELEASE &&
 575             n->protocol == NETLINK_IP6_FW && n->pid) {
 576                 write_lock_bh(&queue_lock);
 577                 if (n->pid == peer_pid)
 578                         __ipq_reset();
 579                 write_unlock_bh(&queue_lock);
 580         }
 581         return NOTIFY_DONE;
 582 }
 583
 584 static struct notifier_block ipq_nl_notifier = {
 585         .notifier_call  = ipq_rcv_nl_event,
 586 };
 587
 588 static struct ctl_table_header *ipq_sysctl_header;
 589
 590 static ctl_table ipq_table[] = {
 591         {
 592                 .ctl_name       = NET_IPQ_QMAX,
 593                 .procname       = NET_IPQ_QMAX_NAME,
 594                 .data           = &queue_maxlen,
 595                 .maxlen         = sizeof(queue_maxlen),
 596                 .mode           = 0644,
 597                 .proc_handler   = proc_dointvec
 598         },
 599         { .ctl_name = 0 }
 600 };
 601
 602 static ctl_table ipq_dir_table[] = {
 603         {
 604                 .ctl_name       = NET_IPV6,
 605                 .procname       = "ipv6",
 606                 .mode           = 0555,
 607                 .child          = ipq_table
 608         },
 609         { .ctl_name = 0 }
 610 };
 611
 612 static ctl_table ipq_root_table[] = {
 613         {
 614                 .ctl_name       = CTL_NET,
 615                 .procname       = "net",
 616                 .mode           = 0555,
 617                 .child          = ipq_dir_table
 618         },
 619         { .ctl_name = 0 }
 620 };
 621
 622 static int
 623 ipq_get_info(char *buffer, char **start, off_t offset, int length)
 624 {
 625         int len;
 626
 627         read_lock_bh(&queue_lock);
 628
 629         len = sprintf(buffer,
 630                       "Peer PID          : %d\n"
 631                       "Copy mode         : %hu\n"
 632                       "Copy range        : %u\n"
 633                       "Queue length      : %u\n"
 634                       "Queue max. length : %u\n"
 635                       "Queue dropped     : %u\n"
 636                       "Netfilter dropped : %u\n",
 637                       peer_pid,
 638                       copy_mode,
 639                       copy_range,
 640                       queue_total,
 641                       queue_maxlen,
 642                       queue_dropped,
 643                       queue_user_dropped);
 644
 645         read_unlock_bh(&queue_lock);
 646
 647         *start = buffer + offset;
 648         len -= offset;
 649         if (len > length)
 650                 len = length;
 651         else if (len < 0)
 652                 len = 0;
 653         return len;
 654 }
 655
 656 static struct nf_queue_handler nfqh = {
 657         .name   = "ip6_queue",
 658         .outfn  = &ipq_enqueue_packet,
 659 };
 660
 661 static int __init ip6_queue_init(void)
 662 {
 663         int status = -ENOMEM;
 664         struct proc_dir_entry *proc;
 665
 666         netlink_register_notifier(&ipq_nl_notifier);
 667         ipqnl = netlink_kernel_create(NETLINK_IP6_FW, 0, ipq_rcv_sk,
 668                                       THIS_MODULE);
 669         if (ipqnl == NULL) {
 670                 printk(KERN_ERR "ip6_queue: failed to create netlink socket\n");
 671                 goto cleanup_netlink_notifier;
 672         }
 673
 674         proc = proc_net_create(IPQ_PROC_FS_NAME, 0, ipq_get_info);
 675         if (proc)
 676                 proc->owner = THIS_MODULE;
 677         else {
 678                 printk(KERN_ERR "ip6_queue: failed to create proc entry\n");
 679                 goto cleanup_ipqnl;
 680         }
 681
 682         register_netdevice_notifier(&ipq_dev_notifier);
 683         ipq_sysctl_header = register_sysctl_table(ipq_root_table, 0);
 684
 685         status = nf_register_queue_handler(PF_INET6, &nfqh);
 686         if (status < 0) {
 687                 printk(KERN_ERR "ip6_queue: failed to register queue handler\n");
 688                 goto cleanup_sysctl;
 689         }
 690         return status;
 691
 692 cleanup_sysctl:
 693         unregister_sysctl_table(ipq_sysctl_header);
 694         unregister_netdevice_notifier(&ipq_dev_notifier);
 695         proc_net_remove(IPQ_PROC_FS_NAME);
 696
 697 cleanup_ipqnl:
 698         sock_release(ipqnl->sk_socket);
 699         mutex_lock(&ipqnl_mutex);
 700         mutex_unlock(&ipqnl_mutex);
 701
 702 cleanup_netlink_notifier:
 703         netlink_unregister_notifier(&ipq_nl_notifier);
 704         return status;
 705 }
 706
 707 static void __exit ip6_queue_fini(void)
 708 {
 709         nf_unregister_queue_handlers(&nfqh);
 710         synchronize_net();
 711         ipq_flush(NF_DROP);
 712
 713         unregister_sysctl_table(ipq_sysctl_header);
 714         unregister_netdevice_notifier(&ipq_dev_notifier);
 715         proc_net_remove(IPQ_PROC_FS_NAME);
 716
 717         sock_release(ipqnl->sk_socket);
 718         mutex_lock(&ipqnl_mutex);
 719         mutex_unlock(&ipqnl_mutex);
 720
 721         netlink_unregister_notifier(&ipq_nl_notifier);
 722 }
 723
 724 MODULE_DESCRIPTION("IPv6 packet queue handler");
 725 MODULE_LICENSE("GPL");
 726
 727 module_init(ip6_queue_init);
 728 module_exit(ip6_queue_fini);