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/sock.h>
  28 #include <net/route.h>
  29
  30 #define IPQ_QMAX_DEFAULT 1024
  31 #define IPQ_PROC_FS_NAME "ip_queue"
  32 #define NET_IPQ_QMAX 2088
  33 #define NET_IPQ_QMAX_NAME "ip_queue_maxlen"
  34
  35 struct ipq_queue_entry {
  36         struct list_head list;
  37         struct nf_info *info;
  38         struct sk_buff *skb;
  39 };
  40
  41 typedef int (*ipq_cmpfn)(struct ipq_queue_entry *, unsigned long);
  42
  43 static unsigned char copy_mode __read_mostly = IPQ_COPY_NONE;
  44 static unsigned int queue_maxlen __read_mostly = IPQ_QMAX_DEFAULT;
  45 static DEFINE_RWLOCK(queue_lock);
  46 static int peer_pid __read_mostly;
  47 static unsigned int copy_range __read_mostly;
  48 static unsigned int queue_total;
  49 static unsigned int queue_dropped = 0;
  50 static unsigned int queue_user_dropped = 0;
  51 static struct sock *ipqnl __read_mostly;
  52 static LIST_HEAD(queue_list);
  53 static DEFINE_MUTEX(ipqnl_mutex);
  54
  55 static void
  56 ipq_issue_verdict(struct ipq_queue_entry *entry, int verdict)
  57 {
  58         /* TCP input path (and probably other bits) assume to be called
  59          * from softirq context, not from syscall, like ipq_issue_verdict is
  60          * called.  TCP input path deadlocks with locks taken from timer
  61          * softirq, e.g.  We therefore emulate this by local_bh_disable() */
  62
  63         local_bh_disable();
  64         nf_reinject(entry->skb, entry->info, verdict);
  65         local_bh_enable();
  66
  67         kfree(entry);
  68 }
  69
  70 static inline void
  71 __ipq_enqueue_entry(struct ipq_queue_entry *entry)
  72 {
  73        list_add(&entry->list, &queue_list);
  74        queue_total++;
  75 }
  76
  77 /*
  78  * Find and return a queued entry matched by cmpfn, or return the last
  79  * entry if cmpfn is NULL.
  80  */
  81 static inline struct ipq_queue_entry *
  82 __ipq_find_entry(ipq_cmpfn cmpfn, unsigned long data)
  83 {
  84         struct list_head *p;
  85
  86         list_for_each_prev(p, &queue_list) {
  87                 struct ipq_queue_entry *entry = (struct ipq_queue_entry *)p;
  88
  89                 if (!cmpfn || cmpfn(entry, data))
  90                         return entry;
  91         }
  92         return NULL;
  93 }
  94
  95 static inline void
  96 __ipq_dequeue_entry(struct ipq_queue_entry *entry)
  97 {
  98         list_del(&entry->list);
  99         queue_total--;
 100 }
 101
 102 static inline struct ipq_queue_entry *
 103 __ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 104 {
 105         struct ipq_queue_entry *entry;
 106
 107         entry = __ipq_find_entry(cmpfn, data);
 108         if (entry == NULL)
 109                 return NULL;
 110
 111         __ipq_dequeue_entry(entry);
 112         return entry;
 113 }
 114
 115
 116 static inline void
 117 __ipq_flush(int verdict)
 118 {
 119         struct ipq_queue_entry *entry;
 120
 121         while ((entry = __ipq_find_dequeue_entry(NULL, 0)))
 122                 ipq_issue_verdict(entry, verdict);
 123 }
 124
 125 static inline int
 126 __ipq_set_mode(unsigned char mode, unsigned int range)
 127 {
 128         int status = 0;
 129
 130         switch(mode) {
 131         case IPQ_COPY_NONE:
 132         case IPQ_COPY_META:
 133                 copy_mode = mode;
 134                 copy_range = 0;
 135                 break;
 136
 137         case IPQ_COPY_PACKET:
 138                 copy_mode = mode;
 139                 copy_range = range;
 140                 if (copy_range > 0xFFFF)
 141                         copy_range = 0xFFFF;
 142                 break;
 143
 144         default:
 145                 status = -EINVAL;
 146
 147         }
 148         return status;
 149 }
 150
 151 static inline void
 152 __ipq_reset(void)
 153 {
 154         peer_pid = 0;
 155         net_disable_timestamp();
 156         __ipq_set_mode(IPQ_COPY_NONE, 0);
 157         __ipq_flush(NF_DROP);
 158 }
 159
 160 static struct ipq_queue_entry *
 161 ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 162 {
 163         struct ipq_queue_entry *entry;
 164
 165         write_lock_bh(&queue_lock);
 166         entry = __ipq_find_dequeue_entry(cmpfn, data);
 167         write_unlock_bh(&queue_lock);
 168         return entry;
 169 }
 170
 171 static void
 172 ipq_flush(int verdict)
 173 {
 174         write_lock_bh(&queue_lock);
 175         __ipq_flush(verdict);
 176         write_unlock_bh(&queue_lock);
 177 }
 178
 179 static struct sk_buff *
 180 ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 181 {
 182         sk_buff_data_t old_tail;
 183         size_t size = 0;
 184         size_t data_len = 0;
 185         struct sk_buff *skb;
 186         struct ipq_packet_msg *pmsg;
 187         struct nlmsghdr *nlh;
 188         struct timeval tv;
 189
 190         read_lock_bh(&queue_lock);
 191
 192         switch (copy_mode) {
 193         case IPQ_COPY_META:
 194         case IPQ_COPY_NONE:
 195                 size = NLMSG_SPACE(sizeof(*pmsg));
 196                 data_len = 0;
 197                 break;
 198
 199         case IPQ_COPY_PACKET:
 200                 if ((entry->skb->ip_summed == CHECKSUM_PARTIAL ||
 201                      entry->skb->ip_summed == CHECKSUM_COMPLETE) &&
 202                     (*errp = skb_checksum_help(entry->skb))) {
 203                         read_unlock_bh(&queue_lock);
 204                         return NULL;
 205                 }
 206                 if (copy_range == 0 || copy_range > entry->skb->len)
 207                         data_len = entry->skb->len;
 208                 else
 209                         data_len = copy_range;
 210
 211                 size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
 212                 break;
 213
 214         default:
 215                 *errp = -EINVAL;
 216                 read_unlock_bh(&queue_lock);
 217                 return NULL;
 218         }
 219
 220         read_unlock_bh(&queue_lock);
 221
 222         skb = alloc_skb(size, GFP_ATOMIC);
 223         if (!skb)
 224                 goto nlmsg_failure;
 225
 226         old_tail = skb->tail;
 227         nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
 228         pmsg = NLMSG_DATA(nlh);
 229         memset(pmsg, 0, sizeof(*pmsg));
 230
 231         pmsg->packet_id       = (unsigned long )entry;
 232         pmsg->data_len        = data_len;
 233         tv = ktime_to_timeval(entry->skb->tstamp);
 234         pmsg->timestamp_sec   = tv.tv_sec;
 235         pmsg->timestamp_usec  = tv.tv_usec;
 236         pmsg->mark            = entry->skb->mark;
 237         pmsg->hook            = entry->info->hook;
 238         pmsg->hw_protocol     = entry->skb->protocol;
 239
 240         if (entry->info->indev)
 241                 strcpy(pmsg->indev_name, entry->info->indev->name);
 242         else
 243                 pmsg->indev_name[0] = '\0';
 244
 245         if (entry->info->outdev)
 246                 strcpy(pmsg->outdev_name, entry->info->outdev->name);
 247         else
 248                 pmsg->outdev_name[0] = '\0';
 249
 250         if (entry->info->indev && entry->skb->dev) {
 251                 pmsg->hw_type = entry->skb->dev->type;
 252                 if (entry->skb->dev->hard_header_parse)
 253                         pmsg->hw_addrlen =
 254                                 entry->skb->dev->hard_header_parse(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         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                         struct sk_buff *newskb;
 352
 353                         newskb = skb_copy_expand(e->skb,
 354                                                  skb_headroom(e->skb),
 355                                                  diff,
 356                                                  GFP_ATOMIC);
 357                         if (newskb == NULL) {
 358                                 printk(KERN_WARNING "ip_queue: OOM "
 359                                       "in mangle, dropping packet\n");
 360                                 return -ENOMEM;
 361                         }
 362                         if (e->skb->sk)
 363                                 skb_set_owner_w(newskb, e->skb->sk);
 364                         kfree_skb(e->skb);
 365                         e->skb = newskb;
 366                 }
 367                 skb_put(e->skb, diff);
 368         }
 369         if (!skb_make_writable(&e->skb, v->data_len))
 370                 return -ENOMEM;
 371         skb_copy_to_linear_data(e->skb, v->payload, v->data_len);
 372         e->skb->ip_summed = CHECKSUM_NONE;
 373
 374         return 0;
 375 }
 376
 377 static inline int
 378 id_cmp(struct ipq_queue_entry *e, unsigned long id)
 379 {
 380         return (id == (unsigned long )e);
 381 }
 382
 383 static int
 384 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
 385 {
 386         struct ipq_queue_entry *entry;
 387
 388         if (vmsg->value > NF_MAX_VERDICT)
 389                 return -EINVAL;
 390
 391         entry = ipq_find_dequeue_entry(id_cmp, vmsg->id);
 392         if (entry == NULL)
 393                 return -ENOENT;
 394         else {
 395                 int verdict = vmsg->value;
 396
 397                 if (vmsg->data_len && vmsg->data_len == len)
 398                         if (ipq_mangle_ipv4(vmsg, entry) < 0)
 399                                 verdict = NF_DROP;
 400
 401                 ipq_issue_verdict(entry, verdict);
 402                 return 0;
 403         }
 404 }
 405
 406 static int
 407 ipq_set_mode(unsigned char mode, unsigned int range)
 408 {
 409         int status;
 410
 411         write_lock_bh(&queue_lock);
 412         status = __ipq_set_mode(mode, range);
 413         write_unlock_bh(&queue_lock);
 414         return status;
 415 }
 416
 417 static int
 418 ipq_receive_peer(struct ipq_peer_msg *pmsg,
 419                  unsigned char type, unsigned int len)
 420 {
 421         int status = 0;
 422
 423         if (len < sizeof(*pmsg))
 424                 return -EINVAL;
 425
 426         switch (type) {
 427         case IPQM_MODE:
 428                 status = ipq_set_mode(pmsg->msg.mode.value,
 429                                       pmsg->msg.mode.range);
 430                 break;
 431
 432         case IPQM_VERDICT:
 433                 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
 434                         status = -EINVAL;
 435                 else
 436                         status = ipq_set_verdict(&pmsg->msg.verdict,
 437                                                  len - sizeof(*pmsg));
 438                         break;
 439         default:
 440                 status = -EINVAL;
 441         }
 442         return status;
 443 }
 444
 445 static int
 446 dev_cmp(struct ipq_queue_entry *entry, unsigned long ifindex)
 447 {
 448         if (entry->info->indev)
 449                 if (entry->info->indev->ifindex == ifindex)
 450                         return 1;
 451         if (entry->info->outdev)
 452                 if (entry->info->outdev->ifindex == ifindex)
 453                         return 1;
 454 #ifdef CONFIG_BRIDGE_NETFILTER
 455         if (entry->skb->nf_bridge) {
 456                 if (entry->skb->nf_bridge->physindev &&
 457                     entry->skb->nf_bridge->physindev->ifindex == ifindex)
 458                         return 1;
 459                 if (entry->skb->nf_bridge->physoutdev &&
 460                     entry->skb->nf_bridge->physoutdev->ifindex == ifindex)
 461                         return 1;
 462         }
 463 #endif
 464         return 0;
 465 }
 466
 467 static void
 468 ipq_dev_drop(int ifindex)
 469 {
 470         struct ipq_queue_entry *entry;
 471
 472         while ((entry = ipq_find_dequeue_entry(dev_cmp, ifindex)) != NULL)
 473                 ipq_issue_verdict(entry, NF_DROP);
 474 }
 475
 476 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 477
 478 static inline void
 479 ipq_rcv_skb(struct sk_buff *skb)
 480 {
 481         int status, type, pid, flags, nlmsglen, skblen;
 482         struct nlmsghdr *nlh;
 483
 484         skblen = skb->len;
 485         if (skblen < sizeof(*nlh))
 486                 return;
 487
 488         nlh = nlmsg_hdr(skb);
 489         nlmsglen = nlh->nlmsg_len;
 490         if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
 491                 return;
 492
 493         pid = nlh->nlmsg_pid;
 494         flags = nlh->nlmsg_flags;
 495
 496         if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
 497                 RCV_SKB_FAIL(-EINVAL);
 498
 499         if (flags & MSG_TRUNC)
 500                 RCV_SKB_FAIL(-ECOMM);
 501
 502         type = nlh->nlmsg_type;
 503         if (type < NLMSG_NOOP || type >= IPQM_MAX)
 504                 RCV_SKB_FAIL(-EINVAL);
 505
 506         if (type <= IPQM_BASE)
 507                 return;
 508
 509         if (security_netlink_recv(skb, CAP_NET_ADMIN))
 510                 RCV_SKB_FAIL(-EPERM);
 511
 512         write_lock_bh(&queue_lock);
 513
 514         if (peer_pid) {
 515                 if (peer_pid != pid) {
 516                         write_unlock_bh(&queue_lock);
 517                         RCV_SKB_FAIL(-EBUSY);
 518                 }
 519         } else {
 520                 net_enable_timestamp();
 521                 peer_pid = pid;
 522         }
 523
 524         write_unlock_bh(&queue_lock);
 525
 526         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 527                                   nlmsglen - NLMSG_LENGTH(0));
 528         if (status < 0)
 529                 RCV_SKB_FAIL(status);
 530
 531         if (flags & NLM_F_ACK)
 532                 netlink_ack(skb, nlh, 0);
 533         return;
 534 }
 535
 536 static void
 537 ipq_rcv_sk(struct sock *sk, int len)
 538 {
 539         struct sk_buff *skb;
 540         unsigned int qlen;
 541
 542         mutex_lock(&ipqnl_mutex);
 543
 544         for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
 545                 skb = skb_dequeue(&sk->sk_receive_queue);
 546                 ipq_rcv_skb(skb);
 547                 kfree_skb(skb);
 548         }
 549
 550         mutex_unlock(&ipqnl_mutex);
 551 }
 552
 553 static int
 554 ipq_rcv_dev_event(struct notifier_block *this,
 555                   unsigned long event, void *ptr)
 556 {
 557         struct net_device *dev = ptr;
 558
 559         /* Drop any packets associated with the downed device */
 560         if (event == NETDEV_DOWN)
 561                 ipq_dev_drop(dev->ifindex);
 562         return NOTIFY_DONE;
 563 }
 564
 565 static struct notifier_block ipq_dev_notifier = {
 566         .notifier_call  = ipq_rcv_dev_event,
 567 };
 568
 569 static int
 570 ipq_rcv_nl_event(struct notifier_block *this,
 571                  unsigned long event, void *ptr)
 572 {
 573         struct netlink_notify *n = ptr;
 574
 575         if (event == NETLINK_URELEASE &&
 576             n->protocol == NETLINK_FIREWALL && n->pid) {
 577                 write_lock_bh(&queue_lock);
 578                 if (n->pid == peer_pid)
 579                         __ipq_reset();
 580                 write_unlock_bh(&queue_lock);
 581         }
 582         return NOTIFY_DONE;
 583 }
 584
 585 static struct notifier_block ipq_nl_notifier = {
 586         .notifier_call  = ipq_rcv_nl_event,
 587 };
 588
 589 static struct ctl_table_header *ipq_sysctl_header;
 590
 591 static ctl_table ipq_table[] = {
 592         {
 593                 .ctl_name       = NET_IPQ_QMAX,
 594                 .procname       = NET_IPQ_QMAX_NAME,
 595                 .data           = &queue_maxlen,
 596                 .maxlen         = sizeof(queue_maxlen),
 597                 .mode           = 0644,
 598                 .proc_handler   = proc_dointvec
 599         },
 600         { .ctl_name = 0 }
 601 };
 602
 603 static ctl_table ipq_dir_table[] = {
 604         {
 605                 .ctl_name       = NET_IPV4,
 606                 .procname       = "ipv4",
 607                 .mode           = 0555,
 608                 .child          = ipq_table
 609         },
 610         { .ctl_name = 0 }
 611 };
 612
 613 static ctl_table ipq_root_table[] = {
 614         {
 615                 .ctl_name       = CTL_NET,
 616                 .procname       = "net",
 617                 .mode           = 0555,
 618                 .child          = ipq_dir_table
 619         },
 620         { .ctl_name = 0 }
 621 };
 622
 623 #ifdef CONFIG_PROC_FS
 624 static int
 625 ipq_get_info(char *buffer, char **start, off_t offset, int length)
 626 {
 627         int len;
 628
 629         read_lock_bh(&queue_lock);
 630
 631         len = sprintf(buffer,
 632                       "Peer PID          : %d\n"
 633                       "Copy mode         : %hu\n"
 634                       "Copy range        : %u\n"
 635                       "Queue length      : %u\n"
 636                       "Queue max. length : %u\n"
 637                       "Queue dropped     : %u\n"
 638                       "Netlink dropped   : %u\n",
 639                       peer_pid,
 640                       copy_mode,
 641                       copy_range,
 642                       queue_total,
 643                       queue_maxlen,
 644                       queue_dropped,
 645                       queue_user_dropped);
 646
 647         read_unlock_bh(&queue_lock);
 648
 649         *start = buffer + offset;
 650         len -= offset;
 651         if (len > length)
 652                 len = length;
 653         else if (len < 0)
 654                 len = 0;
 655         return len;
 656 }
 657 #endif /* CONFIG_PROC_FS */
 658
 659 static struct nf_queue_handler nfqh = {
 660         .name   = "ip_queue",
 661         .outfn  = &ipq_enqueue_packet,
 662 };
 663
 664 static int __init ip_queue_init(void)
 665 {
 666         int status = -ENOMEM;
 667         struct proc_dir_entry *proc;
 668
 669         netlink_register_notifier(&ipq_nl_notifier);
 670         ipqnl = netlink_kernel_create(NETLINK_FIREWALL, 0, ipq_rcv_sk,
 671                                       NULL, THIS_MODULE);
 672         if (ipqnl == NULL) {
 673                 printk(KERN_ERR "ip_queue: failed to create netlink socket\n");
 674                 goto cleanup_netlink_notifier;
 675         }
 676
 677         proc = proc_net_create(IPQ_PROC_FS_NAME, 0, ipq_get_info);
 678         if (proc)
 679                 proc->owner = THIS_MODULE;
 680         else {
 681                 printk(KERN_ERR "ip_queue: failed to create proc entry\n");
 682                 goto cleanup_ipqnl;
 683         }
 684
 685         register_netdevice_notifier(&ipq_dev_notifier);
 686         ipq_sysctl_header = register_sysctl_table(ipq_root_table);
 687
 688         status = nf_register_queue_handler(PF_INET, &nfqh);
 689         if (status < 0) {
 690                 printk(KERN_ERR "ip_queue: failed to register queue handler\n");
 691                 goto cleanup_sysctl;
 692         }
 693         return status;
 694
 695 cleanup_sysctl:
 696         unregister_sysctl_table(ipq_sysctl_header);
 697         unregister_netdevice_notifier(&ipq_dev_notifier);
 698         proc_net_remove(IPQ_PROC_FS_NAME);
 699
 700 cleanup_ipqnl:
 701         sock_release(ipqnl->sk_socket);
 702         mutex_lock(&ipqnl_mutex);
 703         mutex_unlock(&ipqnl_mutex);
 704
 705 cleanup_netlink_notifier:
 706         netlink_unregister_notifier(&ipq_nl_notifier);
 707         return status;
 708 }
 709
 710 static void __exit ip_queue_fini(void)
 711 {
 712         nf_unregister_queue_handlers(&nfqh);
 713         synchronize_net();
 714         ipq_flush(NF_DROP);
 715
 716         unregister_sysctl_table(ipq_sysctl_header);
 717         unregister_netdevice_notifier(&ipq_dev_notifier);
 718         proc_net_remove(IPQ_PROC_FS_NAME);
 719
 720         sock_release(ipqnl->sk_socket);
 721         mutex_lock(&ipqnl_mutex);
 722         mutex_unlock(&ipqnl_mutex);
 723
 724         netlink_unregister_notifier(&ipq_nl_notifier);
 725 }
 726
 727 MODULE_DESCRIPTION("IPv4 packet queue handler");
 728 MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
 729 MODULE_LICENSE("GPL");
 730
 731 module_init(ip_queue_init);
 732 module_exit(ip_queue_fini);