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                 if (entry->skb->dev->hard_header_parse)
 254                         pmsg->hw_addrlen =
 255                                 entry->skb->dev->hard_header_parse(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, void *data)
 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         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                         struct sk_buff *newskb;
 353
 354                         newskb = skb_copy_expand(e->skb,
 355                                                  skb_headroom(e->skb),
 356                                                  diff,
 357                                                  GFP_ATOMIC);
 358                         if (newskb == NULL) {
 359                                 printk(KERN_WARNING "ip_queue: OOM "
 360                                       "in mangle, dropping packet\n");
 361                                 return -ENOMEM;
 362                         }
 363                         if (e->skb->sk)
 364                                 skb_set_owner_w(newskb, e->skb->sk);
 365                         kfree_skb(e->skb);
 366                         e->skb = newskb;
 367                 }
 368                 skb_put(e->skb, diff);
 369         }
 370         if (!skb_make_writable(&e->skb, v->data_len))
 371                 return -ENOMEM;
 372         skb_copy_to_linear_data(e->skb, v->payload, v->data_len);
 373         e->skb->ip_summed = CHECKSUM_NONE;
 374
 375         return 0;
 376 }
 377
 378 static inline int
 379 id_cmp(struct ipq_queue_entry *e, unsigned long id)
 380 {
 381         return (id == (unsigned long )e);
 382 }
 383
 384 static int
 385 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
 386 {
 387         struct ipq_queue_entry *entry;
 388
 389         if (vmsg->value > NF_MAX_VERDICT)
 390                 return -EINVAL;
 391
 392         entry = ipq_find_dequeue_entry(id_cmp, vmsg->id);
 393         if (entry == NULL)
 394                 return -ENOENT;
 395         else {
 396                 int verdict = vmsg->value;
 397
 398                 if (vmsg->data_len && vmsg->data_len == len)
 399                         if (ipq_mangle_ipv4(vmsg, entry) < 0)
 400                                 verdict = NF_DROP;
 401
 402                 ipq_issue_verdict(entry, verdict);
 403                 return 0;
 404         }
 405 }
 406
 407 static int
 408 ipq_set_mode(unsigned char mode, unsigned int range)
 409 {
 410         int status;
 411
 412         write_lock_bh(&queue_lock);
 413         status = __ipq_set_mode(mode, range);
 414         write_unlock_bh(&queue_lock);
 415         return status;
 416 }
 417
 418 static int
 419 ipq_receive_peer(struct ipq_peer_msg *pmsg,
 420                  unsigned char type, unsigned int len)
 421 {
 422         int status = 0;
 423
 424         if (len < sizeof(*pmsg))
 425                 return -EINVAL;
 426
 427         switch (type) {
 428         case IPQM_MODE:
 429                 status = ipq_set_mode(pmsg->msg.mode.value,
 430                                       pmsg->msg.mode.range);
 431                 break;
 432
 433         case IPQM_VERDICT:
 434                 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
 435                         status = -EINVAL;
 436                 else
 437                         status = ipq_set_verdict(&pmsg->msg.verdict,
 438                                                  len - sizeof(*pmsg));
 439                         break;
 440         default:
 441                 status = -EINVAL;
 442         }
 443         return status;
 444 }
 445
 446 static int
 447 dev_cmp(struct ipq_queue_entry *entry, unsigned long ifindex)
 448 {
 449         if (entry->info->indev)
 450                 if (entry->info->indev->ifindex == ifindex)
 451                         return 1;
 452         if (entry->info->outdev)
 453                 if (entry->info->outdev->ifindex == ifindex)
 454                         return 1;
 455 #ifdef CONFIG_BRIDGE_NETFILTER
 456         if (entry->skb->nf_bridge) {
 457                 if (entry->skb->nf_bridge->physindev &&
 458                     entry->skb->nf_bridge->physindev->ifindex == ifindex)
 459                         return 1;
 460                 if (entry->skb->nf_bridge->physoutdev &&
 461                     entry->skb->nf_bridge->physoutdev->ifindex == ifindex)
 462                         return 1;
 463         }
 464 #endif
 465         return 0;
 466 }
 467
 468 static void
 469 ipq_dev_drop(int ifindex)
 470 {
 471         struct ipq_queue_entry *entry;
 472
 473         while ((entry = ipq_find_dequeue_entry(dev_cmp, ifindex)) != NULL)
 474                 ipq_issue_verdict(entry, NF_DROP);
 475 }
 476
 477 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 478
 479 static inline void
 480 ipq_rcv_skb(struct sk_buff *skb)
 481 {
 482         int status, type, pid, flags, nlmsglen, skblen;
 483         struct nlmsghdr *nlh;
 484
 485         skblen = skb->len;
 486         if (skblen < sizeof(*nlh))
 487                 return;
 488
 489         nlh = nlmsg_hdr(skb);
 490         nlmsglen = nlh->nlmsg_len;
 491         if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
 492                 return;
 493
 494         pid = nlh->nlmsg_pid;
 495         flags = nlh->nlmsg_flags;
 496
 497         if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
 498                 RCV_SKB_FAIL(-EINVAL);
 499
 500         if (flags & MSG_TRUNC)
 501                 RCV_SKB_FAIL(-ECOMM);
 502
 503         type = nlh->nlmsg_type;
 504         if (type < NLMSG_NOOP || type >= IPQM_MAX)
 505                 RCV_SKB_FAIL(-EINVAL);
 506
 507         if (type <= IPQM_BASE)
 508                 return;
 509
 510         if (security_netlink_recv(skb, CAP_NET_ADMIN))
 511                 RCV_SKB_FAIL(-EPERM);
 512
 513         write_lock_bh(&queue_lock);
 514
 515         if (peer_pid) {
 516                 if (peer_pid != pid) {
 517                         write_unlock_bh(&queue_lock);
 518                         RCV_SKB_FAIL(-EBUSY);
 519                 }
 520         } else {
 521                 net_enable_timestamp();
 522                 peer_pid = pid;
 523         }
 524
 525         write_unlock_bh(&queue_lock);
 526
 527         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 528                                   nlmsglen - NLMSG_LENGTH(0));
 529         if (status < 0)
 530                 RCV_SKB_FAIL(status);
 531
 532         if (flags & NLM_F_ACK)
 533                 netlink_ack(skb, nlh, 0);
 534         return;
 535 }
 536
 537 static void
 538 ipq_rcv_sk(struct sock *sk, int len)
 539 {
 540         struct sk_buff *skb;
 541         unsigned int qlen;
 542
 543         mutex_lock(&ipqnl_mutex);
 544
 545         for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
 546                 skb = skb_dequeue(&sk->sk_receive_queue);
 547                 ipq_rcv_skb(skb);
 548                 kfree_skb(skb);
 549         }
 550
 551         mutex_unlock(&ipqnl_mutex);
 552 }
 553
 554 static int
 555 ipq_rcv_dev_event(struct notifier_block *this,
 556                   unsigned long event, void *ptr)
 557 {
 558         struct net_device *dev = ptr;
 559
 560         if (dev->nd_net != &init_net)
 561                 return NOTIFY_DONE;
 562
 563         /* Drop any packets associated with the downed device */
 564         if (event == NETDEV_DOWN)
 565                 ipq_dev_drop(dev->ifindex);
 566         return NOTIFY_DONE;
 567 }
 568
 569 static struct notifier_block ipq_dev_notifier = {
 570         .notifier_call  = ipq_rcv_dev_event,
 571 };
 572
 573 static int
 574 ipq_rcv_nl_event(struct notifier_block *this,
 575                  unsigned long event, void *ptr)
 576 {
 577         struct netlink_notify *n = ptr;
 578
 579         if (event == NETLINK_URELEASE &&
 580             n->protocol == NETLINK_FIREWALL && n->pid) {
 581                 write_lock_bh(&queue_lock);
 582                 if ((n->net == &init_net) && (n->pid == peer_pid))
 583                         __ipq_reset();
 584                 write_unlock_bh(&queue_lock);
 585         }
 586         return NOTIFY_DONE;
 587 }
 588
 589 static struct notifier_block ipq_nl_notifier = {
 590         .notifier_call  = ipq_rcv_nl_event,
 591 };
 592
 593 static struct ctl_table_header *ipq_sysctl_header;
 594
 595 static ctl_table ipq_table[] = {
 596         {
 597                 .ctl_name       = NET_IPQ_QMAX,
 598                 .procname       = NET_IPQ_QMAX_NAME,
 599                 .data           = &queue_maxlen,
 600                 .maxlen         = sizeof(queue_maxlen),
 601                 .mode           = 0644,
 602                 .proc_handler   = proc_dointvec
 603         },
 604         { .ctl_name = 0 }
 605 };
 606
 607 static ctl_table ipq_dir_table[] = {
 608         {
 609                 .ctl_name       = NET_IPV4,
 610                 .procname       = "ipv4",
 611                 .mode           = 0555,
 612                 .child          = ipq_table
 613         },
 614         { .ctl_name = 0 }
 615 };
 616
 617 static ctl_table ipq_root_table[] = {
 618         {
 619                 .ctl_name       = CTL_NET,
 620                 .procname       = "net",
 621                 .mode           = 0555,
 622                 .child          = ipq_dir_table
 623         },
 624         { .ctl_name = 0 }
 625 };
 626
 627 #ifdef CONFIG_PROC_FS
 628 static int
 629 ipq_get_info(char *buffer, char **start, off_t offset, int length)
 630 {
 631         int len;
 632
 633         read_lock_bh(&queue_lock);
 634
 635         len = sprintf(buffer,
 636                       "Peer PID          : %d\n"
 637                       "Copy mode         : %hu\n"
 638                       "Copy range        : %u\n"
 639                       "Queue length      : %u\n"
 640                       "Queue max. length : %u\n"
 641                       "Queue dropped     : %u\n"
 642                       "Netlink dropped   : %u\n",
 643                       peer_pid,
 644                       copy_mode,
 645                       copy_range,
 646                       queue_total,
 647                       queue_maxlen,
 648                       queue_dropped,
 649                       queue_user_dropped);
 650
 651         read_unlock_bh(&queue_lock);
 652
 653         *start = buffer + offset;
 654         len -= offset;
 655         if (len > length)
 656                 len = length;
 657         else if (len < 0)
 658                 len = 0;
 659         return len;
 660 }
 661 #endif /* CONFIG_PROC_FS */
 662
 663 static struct nf_queue_handler nfqh = {
 664         .name   = "ip_queue",
 665         .outfn  = &ipq_enqueue_packet,
 666 };
 667
 668 static int __init ip_queue_init(void)
 669 {
 670         int status = -ENOMEM;
 671         struct proc_dir_entry *proc;
 672
 673         netlink_register_notifier(&ipq_nl_notifier);
 674         ipqnl = netlink_kernel_create(&init_net, NETLINK_FIREWALL, 0,
 675                                       ipq_rcv_sk, NULL, THIS_MODULE);
 676         if (ipqnl == NULL) {
 677                 printk(KERN_ERR "ip_queue: failed to create netlink socket\n");
 678                 goto cleanup_netlink_notifier;
 679         }
 680
 681         proc = proc_net_create(&init_net, IPQ_PROC_FS_NAME, 0, ipq_get_info);
 682         if (proc)
 683                 proc->owner = THIS_MODULE;
 684         else {
 685                 printk(KERN_ERR "ip_queue: failed to create proc entry\n");
 686                 goto cleanup_ipqnl;
 687         }
 688
 689         register_netdevice_notifier(&ipq_dev_notifier);
 690         ipq_sysctl_header = register_sysctl_table(ipq_root_table);
 691
 692         status = nf_register_queue_handler(PF_INET, &nfqh);
 693         if (status < 0) {
 694                 printk(KERN_ERR "ip_queue: failed to register queue handler\n");
 695                 goto cleanup_sysctl;
 696         }
 697         return status;
 698
 699 cleanup_sysctl:
 700         unregister_sysctl_table(ipq_sysctl_header);
 701         unregister_netdevice_notifier(&ipq_dev_notifier);
 702         proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 703 cleanup_ipqnl:
 704         sock_release(ipqnl->sk_socket);
 705         mutex_lock(&ipqnl_mutex);
 706         mutex_unlock(&ipqnl_mutex);
 707
 708 cleanup_netlink_notifier:
 709         netlink_unregister_notifier(&ipq_nl_notifier);
 710         return status;
 711 }
 712
 713 static void __exit ip_queue_fini(void)
 714 {
 715         nf_unregister_queue_handlers(&nfqh);
 716         synchronize_net();
 717         ipq_flush(NF_DROP);
 718
 719         unregister_sysctl_table(ipq_sysctl_header);
 720         unregister_netdevice_notifier(&ipq_dev_notifier);
 721         proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 722
 723         sock_release(ipqnl->sk_socket);
 724         mutex_lock(&ipqnl_mutex);
 725         mutex_unlock(&ipqnl_mutex);
 726
 727         netlink_unregister_notifier(&ipq_nl_notifier);
 728 }
 729
 730 MODULE_DESCRIPTION("IPv4 packet queue handler");
 731 MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
 732 MODULE_LICENSE("GPL");
 733
 734 module_init(ip_queue_init);
 735 module_exit(ip_queue_fini);