net/ipv4/netfilter/ip_queue.c

   1 /*
   2  * This is a module which is used for queueing IPv4 packets and
   3  * communicating with userspace via netlink.
   4  *
   5  * (C) 2000-2002 James Morris <jmorris@intercode.com.au>
   6  * (C) 2003-2005 Netfilter Core Team <coreteam@netfilter.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12 #include <linux/module.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/init.h>
  15 #include <linux/ip.h>
  16 #include <linux/notifier.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/netfilter.h>
  19 #include <linux/netfilter_ipv4/ip_queue.h>
  20 #include <linux/netfilter_ipv4/ip_tables.h>
  21 #include <linux/netlink.h>
  22 #include <linux/spinlock.h>
  23 #include <linux/sysctl.h>
  24 #include <linux/proc_fs.h>
  25 #include <linux/security.h>
  26 #include <linux/mutex.h>
  27 #include <net/net_namespace.h>
  28 #include <net/sock.h>
  29 #include <net/route.h>
  30
  31 #define IPQ_QMAX_DEFAULT 1024
  32 #define IPQ_PROC_FS_NAME "ip_queue"
  33 #define NET_IPQ_QMAX 2088
  34 #define NET_IPQ_QMAX_NAME "ip_queue_maxlen"
  35
  36 struct ipq_queue_entry {
  37         struct list_head list;
  38         struct nf_info *info;
  39         struct sk_buff *skb;
  40 };
  41
  42 typedef int (*ipq_cmpfn)(struct ipq_queue_entry *, unsigned long);
  43
  44 static unsigned char copy_mode __read_mostly = IPQ_COPY_NONE;
  45 static unsigned int queue_maxlen __read_mostly = IPQ_QMAX_DEFAULT;
  46 static DEFINE_RWLOCK(queue_lock);
  47 static int peer_pid __read_mostly;
  48 static unsigned int copy_range __read_mostly;
  49 static unsigned int queue_total;
  50 static unsigned int queue_dropped = 0;
  51 static unsigned int queue_user_dropped = 0;
  52 static struct sock *ipqnl __read_mostly;
  53 static LIST_HEAD(queue_list);
  54 static DEFINE_MUTEX(ipqnl_mutex);
  55
  56 static void
  57 ipq_issue_verdict(struct ipq_queue_entry *entry, int verdict)
  58 {
  59         /* TCP input path (and probably other bits) assume to be called
  60          * from softirq context, not from syscall, like ipq_issue_verdict is
  61          * called.  TCP input path deadlocks with locks taken from timer
  62          * softirq, e.g.  We therefore emulate this by local_bh_disable() */
  63
  64         local_bh_disable();
  65         nf_reinject(entry->skb, entry->info, verdict);
  66         local_bh_enable();
  67
  68         kfree(entry);
  69 }
  70
  71 static inline void
  72 __ipq_enqueue_entry(struct ipq_queue_entry *entry)
  73 {
  74        list_add(&entry->list, &queue_list);
  75        queue_total++;
  76 }
  77
  78 /*
  79  * Find and return a queued entry matched by cmpfn, or return the last
  80  * entry if cmpfn is NULL.
  81  */
  82 static inline struct ipq_queue_entry *
  83 __ipq_find_entry(ipq_cmpfn cmpfn, unsigned long data)
  84 {
  85         struct list_head *p;
  86
  87         list_for_each_prev(p, &queue_list) {
  88                 struct ipq_queue_entry *entry = (struct ipq_queue_entry *)p;
  89
  90                 if (!cmpfn || cmpfn(entry, data))
  91                         return entry;
  92         }
  93         return NULL;
  94 }
  95
  96 static inline void
  97 __ipq_dequeue_entry(struct ipq_queue_entry *entry)
  98 {
  99         list_del(&entry->list);
 100         queue_total--;
 101 }
 102
 103 static inline struct ipq_queue_entry *
 104 __ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 105 {
 106         struct ipq_queue_entry *entry;
 107
 108         entry = __ipq_find_entry(cmpfn, data);
 109         if (entry == NULL)
 110                 return NULL;
 111
 112         __ipq_dequeue_entry(entry);
 113         return entry;
 114 }
 115
 116
 117 static inline void
 118 __ipq_flush(int verdict)
 119 {
 120         struct ipq_queue_entry *entry;
 121
 122         while ((entry = __ipq_find_dequeue_entry(NULL, 0)))
 123                 ipq_issue_verdict(entry, verdict);
 124 }
 125
 126 static inline int
 127 __ipq_set_mode(unsigned char mode, unsigned int range)
 128 {
 129         int status = 0;
 130
 131         switch(mode) {
 132         case IPQ_COPY_NONE:
 133         case IPQ_COPY_META:
 134                 copy_mode = mode;
 135                 copy_range = 0;
 136                 break;
 137
 138         case IPQ_COPY_PACKET:
 139                 copy_mode = mode;
 140                 copy_range = range;
 141                 if (copy_range > 0xFFFF)
 142                         copy_range = 0xFFFF;
 143                 break;
 144
 145         default:
 146                 status = -EINVAL;
 147
 148         }
 149         return status;
 150 }
 151
 152 static inline void
 153 __ipq_reset(void)
 154 {
 155         peer_pid = 0;
 156         net_disable_timestamp();
 157         __ipq_set_mode(IPQ_COPY_NONE, 0);
 158         __ipq_flush(NF_DROP);
 159 }
 160
 161 static struct ipq_queue_entry *
 162 ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 163 {
 164         struct ipq_queue_entry *entry;
 165
 166         write_lock_bh(&queue_lock);
 167         entry = __ipq_find_dequeue_entry(cmpfn, data);
 168         write_unlock_bh(&queue_lock);
 169         return entry;
 170 }
 171
 172 static void
 173 ipq_flush(int verdict)
 174 {
 175         write_lock_bh(&queue_lock);
 176         __ipq_flush(verdict);
 177         write_unlock_bh(&queue_lock);
 178 }
 179
 180 static struct sk_buff *
 181 ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 182 {
 183         sk_buff_data_t old_tail;
 184         size_t size = 0;
 185         size_t data_len = 0;
 186         struct sk_buff *skb;
 187         struct ipq_packet_msg *pmsg;
 188         struct nlmsghdr *nlh;
 189         struct timeval tv;
 190
 191         read_lock_bh(&queue_lock);
 192
 193         switch (copy_mode) {
 194         case IPQ_COPY_META:
 195         case IPQ_COPY_NONE:
 196                 size = NLMSG_SPACE(sizeof(*pmsg));
 197                 data_len = 0;
 198                 break;
 199
 200         case IPQ_COPY_PACKET:
 201                 if ((entry->skb->ip_summed == CHECKSUM_PARTIAL ||
 202                      entry->skb->ip_summed == CHECKSUM_COMPLETE) &&
 203                     (*errp = skb_checksum_help(entry->skb))) {
 204                         read_unlock_bh(&queue_lock);
 205                         return NULL;
 206                 }
 207                 if (copy_range == 0 || copy_range > entry->skb->len)
 208                         data_len = entry->skb->len;
 209                 else
 210                         data_len = copy_range;
 211
 212                 size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
 213                 break;
 214
 215         default:
 216                 *errp = -EINVAL;
 217                 read_unlock_bh(&queue_lock);
 218                 return NULL;
 219         }
 220
 221         read_unlock_bh(&queue_lock);
 222
 223         skb = alloc_skb(size, GFP_ATOMIC);
 224         if (!skb)
 225                 goto nlmsg_failure;
 226
 227         old_tail = skb->tail;
 228         nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
 229         pmsg = NLMSG_DATA(nlh);
 230         memset(pmsg, 0, sizeof(*pmsg));
 231
 232         pmsg->packet_id       = (unsigned long )entry;
 233         pmsg->data_len        = data_len;
 234         tv = ktime_to_timeval(entry->skb->tstamp);
 235         pmsg->timestamp_sec   = tv.tv_sec;
 236         pmsg->timestamp_usec  = tv.tv_usec;
 237         pmsg->mark            = entry->skb->mark;
 238         pmsg->hook            = entry->info->hook;
 239         pmsg->hw_protocol     = entry->skb->protocol;
 240
 241         if (entry->info->indev)
 242                 strcpy(pmsg->indev_name, entry->info->indev->name);
 243         else
 244                 pmsg->indev_name[0] = '\0';
 245
 246         if (entry->info->outdev)
 247                 strcpy(pmsg->outdev_name, entry->info->outdev->name);
 248         else
 249                 pmsg->outdev_name[0] = '\0';
 250
 251         if (entry->info->indev && entry->skb->dev) {
 252                 pmsg->hw_type = entry->skb->dev->type;
 253                 pmsg->hw_addrlen = dev_parse_header(entry->skb,
 254                                                     pmsg->hw_addr);
 255         }
 256
 257         if (data_len)
 258                 if (skb_copy_bits(entry->skb, 0, pmsg->payload, data_len))
 259                         BUG();
 260
 261         nlh->nlmsg_len = skb->tail - old_tail;
 262         return skb;
 263
 264 nlmsg_failure:
 265         if (skb)
 266                 kfree_skb(skb);
 267         *errp = -EINVAL;
 268         printk(KERN_ERR "ip_queue: error creating packet message\n");
 269         return NULL;
 270 }
 271
 272 static int
 273 ipq_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
 274                    unsigned int queuenum, void *data)
 275 {
 276         int status = -EINVAL;
 277         struct sk_buff *nskb;
 278         struct ipq_queue_entry *entry;
 279
 280         if (copy_mode == IPQ_COPY_NONE)
 281                 return -EAGAIN;
 282
 283         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 284         if (entry == NULL) {
 285                 printk(KERN_ERR "ip_queue: OOM in ipq_enqueue_packet()\n");
 286                 return -ENOMEM;
 287         }
 288
 289         entry->info = info;
 290         entry->skb = skb;
 291
 292         nskb = ipq_build_packet_message(entry, &status);
 293         if (nskb == NULL)
 294                 goto err_out_free;
 295
 296         write_lock_bh(&queue_lock);
 297
 298         if (!peer_pid)
 299                 goto err_out_free_nskb;
 300
 301         if (queue_total >= queue_maxlen) {
 302                 queue_dropped++;
 303                 status = -ENOSPC;
 304                 if (net_ratelimit())
 305                           printk (KERN_WARNING "ip_queue: full at %d entries, "
 306                                   "dropping packets(s). Dropped: %d\n", queue_total,
 307                                   queue_dropped);
 308                 goto err_out_free_nskb;
 309         }
 310
 311         /* netlink_unicast will either free the nskb or attach it to a socket */
 312         status = netlink_unicast(ipqnl, nskb, peer_pid, MSG_DONTWAIT);
 313         if (status < 0) {
 314                 queue_user_dropped++;
 315                 goto err_out_unlock;
 316         }
 317
 318         __ipq_enqueue_entry(entry);
 319
 320         write_unlock_bh(&queue_lock);
 321         return status;
 322
 323 err_out_free_nskb:
 324         kfree_skb(nskb);
 325
 326 err_out_unlock:
 327         write_unlock_bh(&queue_lock);
 328
 329 err_out_free:
 330         kfree(entry);
 331         return status;
 332 }
 333
 334 static int
 335 ipq_mangle_ipv4(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
 336 {
 337         int diff;
 338         int err;
 339         struct iphdr *user_iph = (struct iphdr *)v->payload;
 340
 341         if (v->data_len < sizeof(*user_iph))
 342                 return 0;
 343         diff = v->data_len - e->skb->len;
 344         if (diff < 0) {
 345                 if (pskb_trim(e->skb, v->data_len))
 346                         return -ENOMEM;
 347         } else if (diff > 0) {
 348                 if (v->data_len > 0xFFFF)
 349                         return -EINVAL;
 350                 if (diff > skb_tailroom(e->skb)) {
 351                         err = pskb_expand_head(e->skb, 0,
 352                                                diff - skb_tailroom(e->skb),
 353                                                GFP_ATOMIC);
 354                         if (err) {
 355                                 printk(KERN_WARNING "ip_queue: error "
 356                                       "in mangle, dropping packet: %d\n", -err);
 357                                 return err;
 358                         }
 359                 }
 360                 skb_put(e->skb, diff);
 361         }
 362         if (!skb_make_writable(e->skb, v->data_len))
 363                 return -ENOMEM;
 364         skb_copy_to_linear_data(e->skb, v->payload, v->data_len);
 365         e->skb->ip_summed = CHECKSUM_NONE;
 366
 367         return 0;
 368 }
 369
 370 static inline int
 371 id_cmp(struct ipq_queue_entry *e, unsigned long id)
 372 {
 373         return (id == (unsigned long )e);
 374 }
 375
 376 static int
 377 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
 378 {
 379         struct ipq_queue_entry *entry;
 380
 381         if (vmsg->value > NF_MAX_VERDICT)
 382                 return -EINVAL;
 383
 384         entry = ipq_find_dequeue_entry(id_cmp, vmsg->id);
 385         if (entry == NULL)
 386                 return -ENOENT;
 387         else {
 388                 int verdict = vmsg->value;
 389
 390                 if (vmsg->data_len && vmsg->data_len == len)
 391                         if (ipq_mangle_ipv4(vmsg, entry) < 0)
 392                                 verdict = NF_DROP;
 393
 394                 ipq_issue_verdict(entry, verdict);
 395                 return 0;
 396         }
 397 }
 398
 399 static int
 400 ipq_set_mode(unsigned char mode, unsigned int range)
 401 {
 402         int status;
 403
 404         write_lock_bh(&queue_lock);
 405         status = __ipq_set_mode(mode, range);
 406         write_unlock_bh(&queue_lock);
 407         return status;
 408 }
 409
 410 static int
 411 ipq_receive_peer(struct ipq_peer_msg *pmsg,
 412                  unsigned char type, unsigned int len)
 413 {
 414         int status = 0;
 415
 416         if (len < sizeof(*pmsg))
 417                 return -EINVAL;
 418
 419         switch (type) {
 420         case IPQM_MODE:
 421                 status = ipq_set_mode(pmsg->msg.mode.value,
 422                                       pmsg->msg.mode.range);
 423                 break;
 424
 425         case IPQM_VERDICT:
 426                 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
 427                         status = -EINVAL;
 428                 else
 429                         status = ipq_set_verdict(&pmsg->msg.verdict,
 430                                                  len - sizeof(*pmsg));
 431                         break;
 432         default:
 433                 status = -EINVAL;
 434         }
 435         return status;
 436 }
 437
 438 static int
 439 dev_cmp(struct ipq_queue_entry *entry, unsigned long ifindex)
 440 {
 441         if (entry->info->indev)
 442                 if (entry->info->indev->ifindex == ifindex)
 443                         return 1;
 444         if (entry->info->outdev)
 445                 if (entry->info->outdev->ifindex == ifindex)
 446                         return 1;
 447 #ifdef CONFIG_BRIDGE_NETFILTER
 448         if (entry->skb->nf_bridge) {
 449                 if (entry->skb->nf_bridge->physindev &&
 450                     entry->skb->nf_bridge->physindev->ifindex == ifindex)
 451                         return 1;
 452                 if (entry->skb->nf_bridge->physoutdev &&
 453                     entry->skb->nf_bridge->physoutdev->ifindex == ifindex)
 454                         return 1;
 455         }
 456 #endif
 457         return 0;
 458 }
 459
 460 static void
 461 ipq_dev_drop(int ifindex)
 462 {
 463         struct ipq_queue_entry *entry;
 464
 465         while ((entry = ipq_find_dequeue_entry(dev_cmp, ifindex)) != NULL)
 466                 ipq_issue_verdict(entry, NF_DROP);
 467 }
 468
 469 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 470
 471 static inline void
 472 __ipq_rcv_skb(struct sk_buff *skb)
 473 {
 474         int status, type, pid, flags, nlmsglen, skblen;
 475         struct nlmsghdr *nlh;
 476
 477         skblen = skb->len;
 478         if (skblen < sizeof(*nlh))
 479                 return;
 480
 481         nlh = nlmsg_hdr(skb);
 482         nlmsglen = nlh->nlmsg_len;
 483         if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
 484                 return;
 485
 486         pid = nlh->nlmsg_pid;
 487         flags = nlh->nlmsg_flags;
 488
 489         if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
 490                 RCV_SKB_FAIL(-EINVAL);
 491
 492         if (flags & MSG_TRUNC)
 493                 RCV_SKB_FAIL(-ECOMM);
 494
 495         type = nlh->nlmsg_type;
 496         if (type < NLMSG_NOOP || type >= IPQM_MAX)
 497                 RCV_SKB_FAIL(-EINVAL);
 498
 499         if (type <= IPQM_BASE)
 500                 return;
 501
 502         if (security_netlink_recv(skb, CAP_NET_ADMIN))
 503                 RCV_SKB_FAIL(-EPERM);
 504
 505         write_lock_bh(&queue_lock);
 506
 507         if (peer_pid) {
 508                 if (peer_pid != pid) {
 509                         write_unlock_bh(&queue_lock);
 510                         RCV_SKB_FAIL(-EBUSY);
 511                 }
 512         } else {
 513                 net_enable_timestamp();
 514                 peer_pid = pid;
 515         }
 516
 517         write_unlock_bh(&queue_lock);
 518
 519         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 520                                   nlmsglen - NLMSG_LENGTH(0));
 521         if (status < 0)
 522                 RCV_SKB_FAIL(status);
 523
 524         if (flags & NLM_F_ACK)
 525                 netlink_ack(skb, nlh, 0);
 526         return;
 527 }
 528
 529 static void
 530 ipq_rcv_skb(struct sk_buff *skb)
 531 {
 532         mutex_lock(&ipqnl_mutex);
 533         __ipq_rcv_skb(skb);
 534         mutex_unlock(&ipqnl_mutex);
 535 }
 536
 537 static int
 538 ipq_rcv_dev_event(struct notifier_block *this,
 539                   unsigned long event, void *ptr)
 540 {
 541         struct net_device *dev = ptr;
 542
 543         if (dev->nd_net != &init_net)
 544                 return NOTIFY_DONE;
 545
 546         /* Drop any packets associated with the downed device */
 547         if (event == NETDEV_DOWN)
 548                 ipq_dev_drop(dev->ifindex);
 549         return NOTIFY_DONE;
 550 }
 551
 552 static struct notifier_block ipq_dev_notifier = {
 553         .notifier_call  = ipq_rcv_dev_event,
 554 };
 555
 556 static int
 557 ipq_rcv_nl_event(struct notifier_block *this,
 558                  unsigned long event, void *ptr)
 559 {
 560         struct netlink_notify *n = ptr;
 561
 562         if (event == NETLINK_URELEASE &&
 563             n->protocol == NETLINK_FIREWALL && n->pid) {
 564                 write_lock_bh(&queue_lock);
 565                 if ((n->net == &init_net) && (n->pid == peer_pid))
 566                         __ipq_reset();
 567                 write_unlock_bh(&queue_lock);
 568         }
 569         return NOTIFY_DONE;
 570 }
 571
 572 static struct notifier_block ipq_nl_notifier = {
 573         .notifier_call  = ipq_rcv_nl_event,
 574 };
 575
 576 static struct ctl_table_header *ipq_sysctl_header;
 577
 578 static ctl_table ipq_table[] = {
 579         {
 580                 .ctl_name       = NET_IPQ_QMAX,
 581                 .procname       = NET_IPQ_QMAX_NAME,
 582                 .data           = &queue_maxlen,
 583                 .maxlen         = sizeof(queue_maxlen),
 584                 .mode           = 0644,
 585                 .proc_handler   = proc_dointvec
 586         },
 587         { .ctl_name = 0 }
 588 };
 589
 590 static ctl_table ipq_dir_table[] = {
 591         {
 592                 .ctl_name       = NET_IPV4,
 593                 .procname       = "ipv4",
 594                 .mode           = 0555,
 595                 .child          = ipq_table
 596         },
 597         { .ctl_name = 0 }
 598 };
 599
 600 static ctl_table ipq_root_table[] = {
 601         {
 602                 .ctl_name       = CTL_NET,
 603                 .procname       = "net",
 604                 .mode           = 0555,
 605                 .child          = ipq_dir_table
 606         },
 607         { .ctl_name = 0 }
 608 };
 609
 610 #ifdef CONFIG_PROC_FS
 611 static int
 612 ipq_get_info(char *buffer, char **start, off_t offset, int length)
 613 {
 614         int len;
 615
 616         read_lock_bh(&queue_lock);
 617
 618         len = sprintf(buffer,
 619                       "Peer PID          : %d\n"
 620                       "Copy mode         : %hu\n"
 621                       "Copy range        : %u\n"
 622                       "Queue length      : %u\n"
 623                       "Queue max. length : %u\n"
 624                       "Queue dropped     : %u\n"
 625                       "Netlink dropped   : %u\n",
 626                       peer_pid,
 627                       copy_mode,
 628                       copy_range,
 629                       queue_total,
 630                       queue_maxlen,
 631                       queue_dropped,
 632                       queue_user_dropped);
 633
 634         read_unlock_bh(&queue_lock);
 635
 636         *start = buffer + offset;
 637         len -= offset;
 638         if (len > length)
 639                 len = length;
 640         else if (len < 0)
 641                 len = 0;
 642         return len;
 643 }
 644 #endif /* CONFIG_PROC_FS */
 645
 646 static struct nf_queue_handler nfqh = {
 647         .name   = "ip_queue",
 648         .outfn  = &ipq_enqueue_packet,
 649 };
 650
 651 static int __init ip_queue_init(void)
 652 {
 653         int status = -ENOMEM;
 654         struct proc_dir_entry *proc;
 655
 656         netlink_register_notifier(&ipq_nl_notifier);
 657         ipqnl = netlink_kernel_create(&init_net, NETLINK_FIREWALL, 0,
 658                                       ipq_rcv_skb, NULL, THIS_MODULE);
 659         if (ipqnl == NULL) {
 660                 printk(KERN_ERR "ip_queue: failed to create netlink socket\n");
 661                 goto cleanup_netlink_notifier;
 662         }
 663
 664         proc = proc_net_create(&init_net, IPQ_PROC_FS_NAME, 0, ipq_get_info);
 665         if (proc)
 666                 proc->owner = THIS_MODULE;
 667         else {
 668                 printk(KERN_ERR "ip_queue: failed to create proc entry\n");
 669                 goto cleanup_ipqnl;
 670         }
 671
 672         register_netdevice_notifier(&ipq_dev_notifier);
 673         ipq_sysctl_header = register_sysctl_table(ipq_root_table);
 674
 675         status = nf_register_queue_handler(PF_INET, &nfqh);
 676         if (status < 0) {
 677                 printk(KERN_ERR "ip_queue: failed to register queue handler\n");
 678                 goto cleanup_sysctl;
 679         }
 680         return status;
 681
 682 cleanup_sysctl:
 683         unregister_sysctl_table(ipq_sysctl_header);
 684         unregister_netdevice_notifier(&ipq_dev_notifier);
 685         proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 686 cleanup_ipqnl:
 687         sock_release(ipqnl->sk_socket);
 688         mutex_lock(&ipqnl_mutex);
 689         mutex_unlock(&ipqnl_mutex);
 690
 691 cleanup_netlink_notifier:
 692         netlink_unregister_notifier(&ipq_nl_notifier);
 693         return status;
 694 }
 695
 696 static void __exit ip_queue_fini(void)
 697 {
 698         nf_unregister_queue_handlers(&nfqh);
 699         synchronize_net();
 700         ipq_flush(NF_DROP);
 701
 702         unregister_sysctl_table(ipq_sysctl_header);
 703         unregister_netdevice_notifier(&ipq_dev_notifier);
 704         proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 705
 706         sock_release(ipqnl->sk_socket);
 707         mutex_lock(&ipqnl_mutex);
 708         mutex_unlock(&ipqnl_mutex);
 709
 710         netlink_unregister_notifier(&ipq_nl_notifier);
 711 }
 712
 713 MODULE_DESCRIPTION("IPv4 packet queue handler");
 714 MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
 715 MODULE_LICENSE("GPL");
 716
 717 module_init(ip_queue_init);
 718 module_exit(ip_queue_fini);