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