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/seq_file.h>
  26 #include <linux/security.h>
  27 #include <linux/mutex.h>
  28 #include <net/net_namespace.h>
  29 #include <net/sock.h>
  30 #include <net/route.h>
  31 #include <net/netfilter/nf_queue.h>
  32
  33 #define IPQ_QMAX_DEFAULT 1024
  34 #define IPQ_PROC_FS_NAME "ip_queue"
  35 #define NET_IPQ_QMAX 2088
  36 #define NET_IPQ_QMAX_NAME "ip_queue_maxlen"
  37
  38 struct ipq_queue_entry {
  39         struct list_head list;
  40         struct nf_info *info;
  41         struct sk_buff *skb;
  42 };
  43
  44 typedef int (*ipq_cmpfn)(struct ipq_queue_entry *, unsigned long);
  45
  46 static unsigned char copy_mode __read_mostly = IPQ_COPY_NONE;
  47 static unsigned int queue_maxlen __read_mostly = IPQ_QMAX_DEFAULT;
  48 static DEFINE_RWLOCK(queue_lock);
  49 static int peer_pid __read_mostly;
  50 static unsigned int copy_range __read_mostly;
  51 static unsigned int queue_total;
  52 static unsigned int queue_dropped = 0;
  53 static unsigned int queue_user_dropped = 0;
  54 static struct sock *ipqnl __read_mostly;
  55 static LIST_HEAD(queue_list);
  56 static DEFINE_MUTEX(ipqnl_mutex);
  57
  58 static void
  59 ipq_issue_verdict(struct ipq_queue_entry *entry, int verdict)
  60 {
  61         /* TCP input path (and probably other bits) assume to be called
  62          * from softirq context, not from syscall, like ipq_issue_verdict is
  63          * called.  TCP input path deadlocks with locks taken from timer
  64          * softirq, e.g.  We therefore emulate this by local_bh_disable() */
  65
  66         local_bh_disable();
  67         nf_reinject(entry->skb, entry->info, verdict);
  68         local_bh_enable();
  69
  70         kfree(entry);
  71 }
  72
  73 static inline void
  74 __ipq_enqueue_entry(struct ipq_queue_entry *entry)
  75 {
  76        list_add(&entry->list, &queue_list);
  77        queue_total++;
  78 }
  79
  80 /*
  81  * Find and return a queued entry matched by cmpfn, or return the last
  82  * entry if cmpfn is NULL.
  83  */
  84 static inline struct ipq_queue_entry *
  85 __ipq_find_entry(ipq_cmpfn cmpfn, unsigned long data)
  86 {
  87         struct list_head *p;
  88
  89         list_for_each_prev(p, &queue_list) {
  90                 struct ipq_queue_entry *entry = (struct ipq_queue_entry *)p;
  91
  92                 if (!cmpfn || cmpfn(entry, data))
  93                         return entry;
  94         }
  95         return NULL;
  96 }
  97
  98 static inline void
  99 __ipq_dequeue_entry(struct ipq_queue_entry *entry)
 100 {
 101         list_del(&entry->list);
 102         queue_total--;
 103 }
 104
 105 static inline struct ipq_queue_entry *
 106 __ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 107 {
 108         struct ipq_queue_entry *entry;
 109
 110         entry = __ipq_find_entry(cmpfn, data);
 111         if (entry == NULL)
 112                 return NULL;
 113
 114         __ipq_dequeue_entry(entry);
 115         return entry;
 116 }
 117
 118
 119 static inline void
 120 __ipq_flush(int verdict)
 121 {
 122         struct ipq_queue_entry *entry;
 123
 124         while ((entry = __ipq_find_dequeue_entry(NULL, 0)))
 125                 ipq_issue_verdict(entry, verdict);
 126 }
 127
 128 static inline int
 129 __ipq_set_mode(unsigned char mode, unsigned int range)
 130 {
 131         int status = 0;
 132
 133         switch(mode) {
 134         case IPQ_COPY_NONE:
 135         case IPQ_COPY_META:
 136                 copy_mode = mode;
 137                 copy_range = 0;
 138                 break;
 139
 140         case IPQ_COPY_PACKET:
 141                 copy_mode = mode;
 142                 copy_range = range;
 143                 if (copy_range > 0xFFFF)
 144                         copy_range = 0xFFFF;
 145                 break;
 146
 147         default:
 148                 status = -EINVAL;
 149
 150         }
 151         return status;
 152 }
 153
 154 static inline void
 155 __ipq_reset(void)
 156 {
 157         peer_pid = 0;
 158         net_disable_timestamp();
 159         __ipq_set_mode(IPQ_COPY_NONE, 0);
 160         __ipq_flush(NF_DROP);
 161 }
 162
 163 static struct ipq_queue_entry *
 164 ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 165 {
 166         struct ipq_queue_entry *entry;
 167
 168         write_lock_bh(&queue_lock);
 169         entry = __ipq_find_dequeue_entry(cmpfn, data);
 170         write_unlock_bh(&queue_lock);
 171         return entry;
 172 }
 173
 174 static void
 175 ipq_flush(int verdict)
 176 {
 177         write_lock_bh(&queue_lock);
 178         __ipq_flush(verdict);
 179         write_unlock_bh(&queue_lock);
 180 }
 181
 182 static struct sk_buff *
 183 ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 184 {
 185         sk_buff_data_t old_tail;
 186         size_t size = 0;
 187         size_t data_len = 0;
 188         struct sk_buff *skb;
 189         struct ipq_packet_msg *pmsg;
 190         struct nlmsghdr *nlh;
 191         struct timeval tv;
 192
 193         read_lock_bh(&queue_lock);
 194
 195         switch (copy_mode) {
 196         case IPQ_COPY_META:
 197         case IPQ_COPY_NONE:
 198                 size = NLMSG_SPACE(sizeof(*pmsg));
 199                 data_len = 0;
 200                 break;
 201
 202         case IPQ_COPY_PACKET:
 203                 if ((entry->skb->ip_summed == CHECKSUM_PARTIAL ||
 204                      entry->skb->ip_summed == CHECKSUM_COMPLETE) &&
 205                     (*errp = skb_checksum_help(entry->skb))) {
 206                         read_unlock_bh(&queue_lock);
 207                         return NULL;
 208                 }
 209                 if (copy_range == 0 || copy_range > entry->skb->len)
 210                         data_len = entry->skb->len;
 211                 else
 212                         data_len = copy_range;
 213
 214                 size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
 215                 break;
 216
 217         default:
 218                 *errp = -EINVAL;
 219                 read_unlock_bh(&queue_lock);
 220                 return NULL;
 221         }
 222
 223         read_unlock_bh(&queue_lock);
 224
 225         skb = alloc_skb(size, GFP_ATOMIC);
 226         if (!skb)
 227                 goto nlmsg_failure;
 228
 229         old_tail = skb->tail;
 230         nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
 231         pmsg = NLMSG_DATA(nlh);
 232         memset(pmsg, 0, sizeof(*pmsg));
 233
 234         pmsg->packet_id       = (unsigned long )entry;
 235         pmsg->data_len        = data_len;
 236         tv = ktime_to_timeval(entry->skb->tstamp);
 237         pmsg->timestamp_sec   = tv.tv_sec;
 238         pmsg->timestamp_usec  = tv.tv_usec;
 239         pmsg->mark            = entry->skb->mark;
 240         pmsg->hook            = entry->info->hook;
 241         pmsg->hw_protocol     = entry->skb->protocol;
 242
 243         if (entry->info->indev)
 244                 strcpy(pmsg->indev_name, entry->info->indev->name);
 245         else
 246                 pmsg->indev_name[0] = '\0';
 247
 248         if (entry->info->outdev)
 249                 strcpy(pmsg->outdev_name, entry->info->outdev->name);
 250         else
 251                 pmsg->outdev_name[0] = '\0';
 252
 253         if (entry->info->indev && entry->skb->dev) {
 254                 pmsg->hw_type = entry->skb->dev->type;
 255                 pmsg->hw_addrlen = dev_parse_header(entry->skb,
 256                                                     pmsg->hw_addr);
 257         }
 258
 259         if (data_len)
 260                 if (skb_copy_bits(entry->skb, 0, pmsg->payload, data_len))
 261                         BUG();
 262
 263         nlh->nlmsg_len = skb->tail - old_tail;
 264         return skb;
 265
 266 nlmsg_failure:
 267         if (skb)
 268                 kfree_skb(skb);
 269         *errp = -EINVAL;
 270         printk(KERN_ERR "ip_queue: error creating packet message\n");
 271         return NULL;
 272 }
 273
 274 static int
 275 ipq_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
 276                    unsigned int queuenum)
 277 {
 278         int status = -EINVAL;
 279         struct sk_buff *nskb;
 280         struct ipq_queue_entry *entry;
 281
 282         if (copy_mode == IPQ_COPY_NONE)
 283                 return -EAGAIN;
 284
 285         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 286         if (entry == NULL) {
 287                 printk(KERN_ERR "ip_queue: OOM in ipq_enqueue_packet()\n");
 288                 return -ENOMEM;
 289         }
 290
 291         entry->info = info;
 292         entry->skb = skb;
 293
 294         nskb = ipq_build_packet_message(entry, &status);
 295         if (nskb == NULL)
 296                 goto err_out_free;
 297
 298         write_lock_bh(&queue_lock);
 299
 300         if (!peer_pid)
 301                 goto err_out_free_nskb;
 302
 303         if (queue_total >= queue_maxlen) {
 304                 queue_dropped++;
 305                 status = -ENOSPC;
 306                 if (net_ratelimit())
 307                           printk (KERN_WARNING "ip_queue: full at %d entries, "
 308                                   "dropping packets(s). Dropped: %d\n", queue_total,
 309                                   queue_dropped);
 310                 goto err_out_free_nskb;
 311         }
 312
 313         /* netlink_unicast will either free the nskb or attach it to a socket */
 314         status = netlink_unicast(ipqnl, nskb, peer_pid, MSG_DONTWAIT);
 315         if (status < 0) {
 316                 queue_user_dropped++;
 317                 goto err_out_unlock;
 318         }
 319
 320         __ipq_enqueue_entry(entry);
 321
 322         write_unlock_bh(&queue_lock);
 323         return status;
 324
 325 err_out_free_nskb:
 326         kfree_skb(nskb);
 327
 328 err_out_unlock:
 329         write_unlock_bh(&queue_lock);
 330
 331 err_out_free:
 332         kfree(entry);
 333         return status;
 334 }
 335
 336 static int
 337 ipq_mangle_ipv4(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
 338 {
 339         int diff;
 340         int err;
 341         struct iphdr *user_iph = (struct iphdr *)v->payload;
 342
 343         if (v->data_len < sizeof(*user_iph))
 344                 return 0;
 345         diff = v->data_len - e->skb->len;
 346         if (diff < 0) {
 347                 if (pskb_trim(e->skb, v->data_len))
 348                         return -ENOMEM;
 349         } else if (diff > 0) {
 350                 if (v->data_len > 0xFFFF)
 351                         return -EINVAL;
 352                 if (diff > skb_tailroom(e->skb)) {
 353                         err = pskb_expand_head(e->skb, 0,
 354                                                diff - skb_tailroom(e->skb),
 355                                                GFP_ATOMIC);
 356                         if (err) {
 357                                 printk(KERN_WARNING "ip_queue: error "
 358                                       "in mangle, dropping packet: %d\n", -err);
 359                                 return err;
 360                         }
 361                 }
 362                 skb_put(e->skb, diff);
 363         }
 364         if (!skb_make_writable(e->skb, v->data_len))
 365                 return -ENOMEM;
 366         skb_copy_to_linear_data(e->skb, v->payload, v->data_len);
 367         e->skb->ip_summed = CHECKSUM_NONE;
 368
 369         return 0;
 370 }
 371
 372 static inline int
 373 id_cmp(struct ipq_queue_entry *e, unsigned long id)
 374 {
 375         return (id == (unsigned long )e);
 376 }
 377
 378 static int
 379 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
 380 {
 381         struct ipq_queue_entry *entry;
 382
 383         if (vmsg->value > NF_MAX_VERDICT)
 384                 return -EINVAL;
 385
 386         entry = ipq_find_dequeue_entry(id_cmp, vmsg->id);
 387         if (entry == NULL)
 388                 return -ENOENT;
 389         else {
 390                 int verdict = vmsg->value;
 391
 392                 if (vmsg->data_len && vmsg->data_len == len)
 393                         if (ipq_mangle_ipv4(vmsg, entry) < 0)
 394                                 verdict = NF_DROP;
 395
 396                 ipq_issue_verdict(entry, verdict);
 397                 return 0;
 398         }
 399 }
 400
 401 static int
 402 ipq_set_mode(unsigned char mode, unsigned int range)
 403 {
 404         int status;
 405
 406         write_lock_bh(&queue_lock);
 407         status = __ipq_set_mode(mode, range);
 408         write_unlock_bh(&queue_lock);
 409         return status;
 410 }
 411
 412 static int
 413 ipq_receive_peer(struct ipq_peer_msg *pmsg,
 414                  unsigned char type, unsigned int len)
 415 {
 416         int status = 0;
 417
 418         if (len < sizeof(*pmsg))
 419                 return -EINVAL;
 420
 421         switch (type) {
 422         case IPQM_MODE:
 423                 status = ipq_set_mode(pmsg->msg.mode.value,
 424                                       pmsg->msg.mode.range);
 425                 break;
 426
 427         case IPQM_VERDICT:
 428                 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
 429                         status = -EINVAL;
 430                 else
 431                         status = ipq_set_verdict(&pmsg->msg.verdict,
 432                                                  len - sizeof(*pmsg));
 433                         break;
 434         default:
 435                 status = -EINVAL;
 436         }
 437         return status;
 438 }
 439
 440 static int
 441 dev_cmp(struct ipq_queue_entry *entry, unsigned long ifindex)
 442 {
 443         if (entry->info->indev)
 444                 if (entry->info->indev->ifindex == ifindex)
 445                         return 1;
 446         if (entry->info->outdev)
 447                 if (entry->info->outdev->ifindex == ifindex)
 448                         return 1;
 449 #ifdef CONFIG_BRIDGE_NETFILTER
 450         if (entry->skb->nf_bridge) {
 451                 if (entry->skb->nf_bridge->physindev &&
 452                     entry->skb->nf_bridge->physindev->ifindex == ifindex)
 453                         return 1;
 454                 if (entry->skb->nf_bridge->physoutdev &&
 455                     entry->skb->nf_bridge->physoutdev->ifindex == ifindex)
 456                         return 1;
 457         }
 458 #endif
 459         return 0;
 460 }
 461
 462 static void
 463 ipq_dev_drop(int ifindex)
 464 {
 465         struct ipq_queue_entry *entry;
 466
 467         while ((entry = ipq_find_dequeue_entry(dev_cmp, ifindex)) != NULL)
 468                 ipq_issue_verdict(entry, NF_DROP);
 469 }
 470
 471 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 472
 473 static inline void
 474 __ipq_rcv_skb(struct sk_buff *skb)
 475 {
 476         int status, type, pid, flags, nlmsglen, skblen;
 477         struct nlmsghdr *nlh;
 478
 479         skblen = skb->len;
 480         if (skblen < sizeof(*nlh))
 481                 return;
 482
 483         nlh = nlmsg_hdr(skb);
 484         nlmsglen = nlh->nlmsg_len;
 485         if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
 486                 return;
 487
 488         pid = nlh->nlmsg_pid;
 489         flags = nlh->nlmsg_flags;
 490
 491         if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
 492                 RCV_SKB_FAIL(-EINVAL);
 493
 494         if (flags & MSG_TRUNC)
 495                 RCV_SKB_FAIL(-ECOMM);
 496
 497         type = nlh->nlmsg_type;
 498         if (type < NLMSG_NOOP || type >= IPQM_MAX)
 499                 RCV_SKB_FAIL(-EINVAL);
 500
 501         if (type <= IPQM_BASE)
 502                 return;
 503
 504         if (security_netlink_recv(skb, CAP_NET_ADMIN))
 505                 RCV_SKB_FAIL(-EPERM);
 506
 507         write_lock_bh(&queue_lock);
 508
 509         if (peer_pid) {
 510                 if (peer_pid != pid) {
 511                         write_unlock_bh(&queue_lock);
 512                         RCV_SKB_FAIL(-EBUSY);
 513                 }
 514         } else {
 515                 net_enable_timestamp();
 516                 peer_pid = pid;
 517         }
 518
 519         write_unlock_bh(&queue_lock);
 520
 521         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 522                                   nlmsglen - NLMSG_LENGTH(0));
 523         if (status < 0)
 524                 RCV_SKB_FAIL(status);
 525
 526         if (flags & NLM_F_ACK)
 527                 netlink_ack(skb, nlh, 0);
 528         return;
 529 }
 530
 531 static void
 532 ipq_rcv_skb(struct sk_buff *skb)
 533 {
 534         mutex_lock(&ipqnl_mutex);
 535         __ipq_rcv_skb(skb);
 536         mutex_unlock(&ipqnl_mutex);
 537 }
 538
 539 static int
 540 ipq_rcv_dev_event(struct notifier_block *this,
 541                   unsigned long event, void *ptr)
 542 {
 543         struct net_device *dev = ptr;
 544
 545         if (dev->nd_net != &init_net)
 546                 return NOTIFY_DONE;
 547
 548         /* Drop any packets associated with the downed device */
 549         if (event == NETDEV_DOWN)
 550                 ipq_dev_drop(dev->ifindex);
 551         return NOTIFY_DONE;
 552 }
 553
 554 static struct notifier_block ipq_dev_notifier = {
 555         .notifier_call  = ipq_rcv_dev_event,
 556 };
 557
 558 static int
 559 ipq_rcv_nl_event(struct notifier_block *this,
 560                  unsigned long event, void *ptr)
 561 {
 562         struct netlink_notify *n = ptr;
 563
 564         if (event == NETLINK_URELEASE &&
 565             n->protocol == NETLINK_FIREWALL && n->pid) {
 566                 write_lock_bh(&queue_lock);
 567                 if ((n->net == &init_net) && (n->pid == peer_pid))
 568                         __ipq_reset();
 569                 write_unlock_bh(&queue_lock);
 570         }
 571         return NOTIFY_DONE;
 572 }
 573
 574 static struct notifier_block ipq_nl_notifier = {
 575         .notifier_call  = ipq_rcv_nl_event,
 576 };
 577
 578 static struct ctl_table_header *ipq_sysctl_header;
 579
 580 static ctl_table ipq_table[] = {
 581         {
 582                 .ctl_name       = NET_IPQ_QMAX,
 583                 .procname       = NET_IPQ_QMAX_NAME,
 584                 .data           = &queue_maxlen,
 585                 .maxlen         = sizeof(queue_maxlen),
 586                 .mode           = 0644,
 587                 .proc_handler   = proc_dointvec
 588         },
 589         { .ctl_name = 0 }
 590 };
 591
 592 static ctl_table ipq_dir_table[] = {
 593         {
 594                 .ctl_name       = NET_IPV4,
 595                 .procname       = "ipv4",
 596                 .mode           = 0555,
 597                 .child          = ipq_table
 598         },
 599         { .ctl_name = 0 }
 600 };
 601
 602 static ctl_table ipq_root_table[] = {
 603         {
 604                 .ctl_name       = CTL_NET,
 605                 .procname       = "net",
 606                 .mode           = 0555,
 607                 .child          = ipq_dir_table
 608         },
 609         { .ctl_name = 0 }
 610 };
 611
 612 static int ip_queue_show(struct seq_file *m, void *v)
 613 {
 614         read_lock_bh(&queue_lock);
 615
 616         seq_printf(m,
 617                       "Peer PID          : %d\n"
 618                       "Copy mode         : %hu\n"
 619                       "Copy range        : %u\n"
 620                       "Queue length      : %u\n"
 621                       "Queue max. length : %u\n"
 622                       "Queue dropped     : %u\n"
 623                       "Netlink dropped   : %u\n",
 624                       peer_pid,
 625                       copy_mode,
 626                       copy_range,
 627                       queue_total,
 628                       queue_maxlen,
 629                       queue_dropped,
 630                       queue_user_dropped);
 631
 632         read_unlock_bh(&queue_lock);
 633         return 0;
 634 }
 635
 636 static int ip_queue_open(struct inode *inode, struct file *file)
 637 {
 638         return single_open(file, ip_queue_show, NULL);
 639 }
 640
 641 static const struct file_operations ip_queue_proc_fops = {
 642         .open           = ip_queue_open,
 643         .read           = seq_read,
 644         .llseek         = seq_lseek,
 645         .release        = single_release,
 646         .owner          = THIS_MODULE,
 647 };
 648
 649 static const struct nf_queue_handler nfqh = {
 650         .name   = "ip_queue",
 651         .outfn  = &ipq_enqueue_packet,
 652 };
 653
 654 static int __init ip_queue_init(void)
 655 {
 656         int status = -ENOMEM;
 657         struct proc_dir_entry *proc;
 658
 659         netlink_register_notifier(&ipq_nl_notifier);
 660         ipqnl = netlink_kernel_create(&init_net, NETLINK_FIREWALL, 0,
 661                                       ipq_rcv_skb, NULL, THIS_MODULE);
 662         if (ipqnl == NULL) {
 663                 printk(KERN_ERR "ip_queue: failed to create netlink socket\n");
 664                 goto cleanup_netlink_notifier;
 665         }
 666
 667         proc = create_proc_entry(IPQ_PROC_FS_NAME, 0, init_net.proc_net);
 668         if (proc) {
 669                 proc->owner = THIS_MODULE;
 670                 proc->proc_fops = &ip_queue_proc_fops;
 671         } else {
 672                 printk(KERN_ERR "ip_queue: failed to create proc entry\n");
 673                 goto cleanup_ipqnl;
 674         }
 675
 676         register_netdevice_notifier(&ipq_dev_notifier);
 677         ipq_sysctl_header = register_sysctl_table(ipq_root_table);
 678
 679         status = nf_register_queue_handler(PF_INET, &nfqh);
 680         if (status < 0) {
 681                 printk(KERN_ERR "ip_queue: failed to register queue handler\n");
 682                 goto cleanup_sysctl;
 683         }
 684         return status;
 685
 686 cleanup_sysctl:
 687         unregister_sysctl_table(ipq_sysctl_header);
 688         unregister_netdevice_notifier(&ipq_dev_notifier);
 689         proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 690 cleanup_ipqnl:
 691         sock_release(ipqnl->sk_socket);
 692         mutex_lock(&ipqnl_mutex);
 693         mutex_unlock(&ipqnl_mutex);
 694
 695 cleanup_netlink_notifier:
 696         netlink_unregister_notifier(&ipq_nl_notifier);
 697         return status;
 698 }
 699
 700 static void __exit ip_queue_fini(void)
 701 {
 702         nf_unregister_queue_handlers(&nfqh);
 703         synchronize_net();
 704         ipq_flush(NF_DROP);
 705
 706         unregister_sysctl_table(ipq_sysctl_header);
 707         unregister_netdevice_notifier(&ipq_dev_notifier);
 708         proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 709
 710         sock_release(ipqnl->sk_socket);
 711         mutex_lock(&ipqnl_mutex);
 712         mutex_unlock(&ipqnl_mutex);
 713
 714         netlink_unregister_notifier(&ipq_nl_notifier);
 715 }
 716
 717 MODULE_DESCRIPTION("IPv4 packet queue handler");
 718 MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
 719 MODULE_LICENSE("GPL");
 720
 721 module_init(ip_queue_init);
 722 module_exit(ip_queue_fini);