net/ipv4/netfilter/ip_queue.c

   1 /*
   2  * This is a module which is used for queueing IPv4 packets and
   3  * communicating with userspace via netlink.
   4  *
   5  * (C) 2000-2002 James Morris <jmorris@intercode.com.au>
   6  * (C) 2003-2005 Netfilter Core Team <coreteam@netfilter.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12 #include <linux/module.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/init.h>
  15 #include <linux/ip.h>
  16 #include <linux/notifier.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/netfilter.h>
  19 #include <linux/netfilter_ipv4/ip_queue.h>
  20 #include <linux/netfilter_ipv4/ip_tables.h>
  21 #include <linux/netlink.h>
  22 #include <linux/spinlock.h>
  23 #include <linux/sysctl.h>
  24 #include <linux/proc_fs.h>
  25 #include <linux/security.h>
  26 #include <linux/mutex.h>
  27 #include <net/net_namespace.h>
  28 #include <net/sock.h>
  29 #include <net/route.h>
  30
  31 #define IPQ_QMAX_DEFAULT 1024
  32 #define IPQ_PROC_FS_NAME "ip_queue"
  33 #define NET_IPQ_QMAX 2088
  34 #define NET_IPQ_QMAX_NAME "ip_queue_maxlen"
  35
  36 struct ipq_queue_entry {
  37         struct list_head list;
  38         struct nf_info *info;
  39         struct sk_buff *skb;
  40 };
  41
  42 typedef int (*ipq_cmpfn)(struct ipq_queue_entry *, unsigned long);
  43
  44 static unsigned char copy_mode __read_mostly = IPQ_COPY_NONE;
  45 static unsigned int queue_maxlen __read_mostly = IPQ_QMAX_DEFAULT;
  46 static DEFINE_RWLOCK(queue_lock);
  47 static int peer_pid __read_mostly;
  48 static unsigned int copy_range __read_mostly;
  49 static unsigned int queue_total;
  50 static unsigned int queue_dropped = 0;
  51 static unsigned int queue_user_dropped = 0;
  52 static struct sock *ipqnl __read_mostly;
  53 static LIST_HEAD(queue_list);
  54 static DEFINE_MUTEX(ipqnl_mutex);
  55
  56 static void
  57 ipq_issue_verdict(struct ipq_queue_entry *entry, int verdict)
  58 {
  59         /* TCP input path (and probably other bits) assume to be called
  60          * from softirq context, not from syscall, like ipq_issue_verdict is
  61          * called.  TCP input path deadlocks with locks taken from timer
  62          * softirq, e.g.  We therefore emulate this by local_bh_disable() */
  63
  64         local_bh_disable();
  65         nf_reinject(entry->skb, entry->info, verdict);
  66         local_bh_enable();
  67
  68         kfree(entry);
  69 }
  70
  71 static inline void
  72 __ipq_enqueue_entry(struct ipq_queue_entry *entry)
  73 {
  74        list_add(&entry->list, &queue_list);
  75        queue_total++;
  76 }
  77
  78 /*
  79  * Find and return a queued entry matched by cmpfn, or return the last
  80  * entry if cmpfn is NULL.
  81  */
  82 static inline struct ipq_queue_entry *
  83 __ipq_find_entry(ipq_cmpfn cmpfn, unsigned long data)
  84 {
  85         struct list_head *p;
  86
  87         list_for_each_prev(p, &queue_list) {
  88                 struct ipq_queue_entry *entry = (struct ipq_queue_entry *)p;
  89
  90                 if (!cmpfn || cmpfn(entry, data))
  91                         return entry;
  92         }
  93         return NULL;
  94 }
  95
  96 static inline void
  97 __ipq_dequeue_entry(struct ipq_queue_entry *entry)
  98 {
  99         list_del(&entry->list);
 100         queue_total--;
 101 }
 102
 103 static inline struct ipq_queue_entry *
 104 __ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 105 {
 106         struct ipq_queue_entry *entry;
 107
 108         entry = __ipq_find_entry(cmpfn, data);
 109         if (entry == NULL)
 110                 return NULL;
 111
 112         __ipq_dequeue_entry(entry);
 113         return entry;
 114 }
 115
 116
 117 static inline void
 118 __ipq_flush(int verdict)
 119 {
 120         struct ipq_queue_entry *entry;
 121
 122         while ((entry = __ipq_find_dequeue_entry(NULL, 0)))
 123                 ipq_issue_verdict(entry, verdict);
 124 }
 125
 126 static inline int
 127 __ipq_set_mode(unsigned char mode, unsigned int range)
 128 {
 129         int status = 0;
 130
 131         switch(mode) {
 132         case IPQ_COPY_NONE:
 133         case IPQ_COPY_META:
 134                 copy_mode = mode;
 135                 copy_range = 0;
 136                 break;
 137
 138         case IPQ_COPY_PACKET:
 139                 copy_mode = mode;
 140                 copy_range = range;
 141                 if (copy_range > 0xFFFF)
 142                         copy_range = 0xFFFF;
 143                 break;
 144
 145         default:
 146                 status = -EINVAL;
 147
 148         }
 149         return status;
 150 }
 151
 152 static inline void
 153 __ipq_reset(void)
 154 {
 155         peer_pid = 0;
 156         net_disable_timestamp();
 157         __ipq_set_mode(IPQ_COPY_NONE, 0);
 158         __ipq_flush(NF_DROP);
 159 }
 160
 161 static struct ipq_queue_entry *
 162 ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 163 {
 164         struct ipq_queue_entry *entry;
 165
 166         write_lock_bh(&queue_lock);
 167         entry = __ipq_find_dequeue_entry(cmpfn, data);
 168         write_unlock_bh(&queue_lock);
 169         return entry;
 170 }
 171
 172 static void
 173 ipq_flush(int verdict)
 174 {
 175         write_lock_bh(&queue_lock);
 176         __ipq_flush(verdict);
 177         write_unlock_bh(&queue_lock);
 178 }
 179
 180 static struct sk_buff *
 181 ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 182 {
 183         sk_buff_data_t old_tail;
 184         size_t size = 0;
 185         size_t data_len = 0;
 186         struct sk_buff *skb;
 187         struct ipq_packet_msg *pmsg;
 188         struct nlmsghdr *nlh;
 189         struct timeval tv;
 190
 191         read_lock_bh(&queue_lock);
 192
 193         switch (copy_mode) {
 194         case IPQ_COPY_META:
 195         case IPQ_COPY_NONE:
 196                 size = NLMSG_SPACE(sizeof(*pmsg));
 197                 data_len = 0;
 198                 break;
 199
 200         case IPQ_COPY_PACKET:
 201                 if ((entry->skb->ip_summed == CHECKSUM_PARTIAL ||
 202                      entry->skb->ip_summed == CHECKSUM_COMPLETE) &&
 203                     (*errp = skb_checksum_help(entry->skb))) {
 204                         read_unlock_bh(&queue_lock);
 205                         return NULL;
 206                 }
 207                 if (copy_range == 0 || copy_range > entry->skb->len)
 208                         data_len = entry->skb->len;
 209                 else
 210                         data_len = copy_range;
 211
 212                 size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
 213                 break;
 214
 215         default:
 216                 *errp = -EINVAL;
 217                 read_unlock_bh(&queue_lock);
 218                 return NULL;
 219         }
 220
 221         read_unlock_bh(&queue_lock);
 222
 223         skb = alloc_skb(size, GFP_ATOMIC);
 224         if (!skb)
 225                 goto nlmsg_failure;
 226
 227         old_tail = skb->tail;
 228         nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
 229         pmsg = NLMSG_DATA(nlh);
 230         memset(pmsg, 0, sizeof(*pmsg));
 231
 232         pmsg->packet_id       = (unsigned long )entry;
 233         pmsg->data_len        = data_len;
 234         tv = ktime_to_timeval(entry->skb->tstamp);
 235         pmsg->timestamp_sec   = tv.tv_sec;
 236         pmsg->timestamp_usec  = tv.tv_usec;
 237         pmsg->mark            = entry->skb->mark;
 238         pmsg->hook            = entry->info->hook;
 239         pmsg->hw_protocol     = entry->skb->protocol;
 240
 241         if (entry->info->indev)
 242                 strcpy(pmsg->indev_name, entry->info->indev->name);
 243         else
 244                 pmsg->indev_name[0] = '\0';
 245
 246         if (entry->info->outdev)
 247                 strcpy(pmsg->outdev_name, entry->info->outdev->name);
 248         else
 249                 pmsg->outdev_name[0] = '\0';
 250
 251         if (entry->info->indev && entry->skb->dev) {
 252                 pmsg->hw_type = entry->skb->dev->type;
 253                 pmsg->hw_addrlen = dev_parse_header(entry->skb,
 254                                                     pmsg->hw_addr);
 255         }
 256
 257         if (data_len)
 258                 if (skb_copy_bits(entry->skb, 0, pmsg->payload, data_len))
 259                         BUG();
 260
 261         nlh->nlmsg_len = skb->tail - old_tail;
 262         return skb;
 263
 264 nlmsg_failure:
 265         if (skb)
 266                 kfree_skb(skb);
 267         *errp = -EINVAL;
 268         printk(KERN_ERR "ip_queue: error creating packet message\n");
 269         return NULL;
 270 }
 271
 272 static int
 273 ipq_enqueue_packet(struct sk_buff *skb, struct nf_info *info,
 274                    unsigned int queuenum, void *data)
 275 {
 276         int status = -EINVAL;
 277         struct sk_buff *nskb;
 278         struct ipq_queue_entry *entry;
 279
 280         if (copy_mode == IPQ_COPY_NONE)
 281                 return -EAGAIN;
 282
 283         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 284         if (entry == NULL) {
 285                 printk(KERN_ERR "ip_queue: OOM in ipq_enqueue_packet()\n");
 286                 return -ENOMEM;
 287         }
 288
 289         entry->info = info;
 290         entry->skb = skb;
 291
 292         nskb = ipq_build_packet_message(entry, &status);
 293         if (nskb == NULL)
 294                 goto err_out_free;
 295
 296         write_lock_bh(&queue_lock);
 297
 298         if (!peer_pid)
 299                 goto err_out_free_nskb;
 300
 301         if (queue_total >= queue_maxlen) {
 302                 queue_dropped++;
 303                 status = -ENOSPC;
 304                 if (net_ratelimit())
 305                           printk (KERN_WARNING "ip_queue: full at %d entries, "
 306                                   "dropping packets(s). Dropped: %d\n", queue_total,
 307                                   queue_dropped);
 308                 goto err_out_free_nskb;
 309         }
 310
 311         /* netlink_unicast will either free the nskb or attach it to a socket */
 312         status = netlink_unicast(ipqnl, nskb, peer_pid, MSG_DONTWAIT);
 313         if (status < 0) {
 314                 queue_user_dropped++;
 315                 goto err_out_unlock;
 316         }
 317
 318         __ipq_enqueue_entry(entry);
 319
 320         write_unlock_bh(&queue_lock);
 321         return status;
 322
 323 err_out_free_nskb:
 324         kfree_skb(nskb);
 325
 326 err_out_unlock:
 327         write_unlock_bh(&queue_lock);
 328
 329 err_out_free:
 330         kfree(entry);
 331         return status;
 332 }
 333
 334 static int
 335 ipq_mangle_ipv4(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
 336 {
 337         int diff;
 338         struct iphdr *user_iph = (struct iphdr *)v->payload;
 339
 340         if (v->data_len < sizeof(*user_iph))
 341                 return 0;
 342         diff = v->data_len - e->skb->len;
 343         if (diff < 0) {
 344                 if (pskb_trim(e->skb, v->data_len))
 345                         return -ENOMEM;
 346         } else if (diff > 0) {
 347                 if (v->data_len > 0xFFFF)
 348                         return -EINVAL;
 349                 if (diff > skb_tailroom(e->skb)) {
 350                         struct sk_buff *newskb;
 351
 352                         newskb = skb_copy_expand(e->skb,
 353                                                  skb_headroom(e->skb),
 354                                                  diff,
 355                                                  GFP_ATOMIC);
 356                         if (newskb == NULL) {
 357                                 printk(KERN_WARNING "ip_queue: OOM "
 358                                       "in mangle, dropping packet\n");
 359                                 return -ENOMEM;
 360                         }
 361                         if (e->skb->sk)
 362                                 skb_set_owner_w(newskb, e->skb->sk);
 363                         kfree_skb(e->skb);
 364                         e->skb = newskb;
 365                 }
 366                 skb_put(e->skb, diff);
 367         }
 368         if (!skb_make_writable(&e->skb, v->data_len))
 369                 return -ENOMEM;
 370         skb_copy_to_linear_data(e->skb, v->payload, v->data_len);
 371         e->skb->ip_summed = CHECKSUM_NONE;
 372
 373         return 0;
 374 }
 375
 376 static inline int
 377 id_cmp(struct ipq_queue_entry *e, unsigned long id)
 378 {
 379         return (id == (unsigned long )e);
 380 }
 381
 382 static int
 383 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
 384 {
 385         struct ipq_queue_entry *entry;
 386
 387         if (vmsg->value > NF_MAX_VERDICT)
 388                 return -EINVAL;
 389
 390         entry = ipq_find_dequeue_entry(id_cmp, vmsg->id);
 391         if (entry == NULL)
 392                 return -ENOENT;
 393         else {
 394                 int verdict = vmsg->value;
 395
 396                 if (vmsg->data_len && vmsg->data_len == len)
 397                         if (ipq_mangle_ipv4(vmsg, entry) < 0)
 398                                 verdict = NF_DROP;
 399
 400                 ipq_issue_verdict(entry, verdict);
 401                 return 0;
 402         }
 403 }
 404
 405 static int
 406 ipq_set_mode(unsigned char mode, unsigned int range)
 407 {
 408         int status;
 409
 410         write_lock_bh(&queue_lock);
 411         status = __ipq_set_mode(mode, range);
 412         write_unlock_bh(&queue_lock);
 413         return status;
 414 }
 415
 416 static int
 417 ipq_receive_peer(struct ipq_peer_msg *pmsg,
 418                  unsigned char type, unsigned int len)
 419 {
 420         int status = 0;
 421
 422         if (len < sizeof(*pmsg))
 423                 return -EINVAL;
 424
 425         switch (type) {
 426         case IPQM_MODE:
 427                 status = ipq_set_mode(pmsg->msg.mode.value,
 428                                       pmsg->msg.mode.range);
 429                 break;
 430
 431         case IPQM_VERDICT:
 432                 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
 433                         status = -EINVAL;
 434                 else
 435                         status = ipq_set_verdict(&pmsg->msg.verdict,
 436                                                  len - sizeof(*pmsg));
 437                         break;
 438         default:
 439                 status = -EINVAL;
 440         }
 441         return status;
 442 }
 443
 444 static int
 445 dev_cmp(struct ipq_queue_entry *entry, unsigned long ifindex)
 446 {
 447         if (entry->info->indev)
 448                 if (entry->info->indev->ifindex == ifindex)
 449                         return 1;
 450         if (entry->info->outdev)
 451                 if (entry->info->outdev->ifindex == ifindex)
 452                         return 1;
 453 #ifdef CONFIG_BRIDGE_NETFILTER
 454         if (entry->skb->nf_bridge) {
 455                 if (entry->skb->nf_bridge->physindev &&
 456                     entry->skb->nf_bridge->physindev->ifindex == ifindex)
 457                         return 1;
 458                 if (entry->skb->nf_bridge->physoutdev &&
 459                     entry->skb->nf_bridge->physoutdev->ifindex == ifindex)
 460                         return 1;
 461         }
 462 #endif
 463         return 0;
 464 }
 465
 466 static void
 467 ipq_dev_drop(int ifindex)
 468 {
 469         struct ipq_queue_entry *entry;
 470
 471         while ((entry = ipq_find_dequeue_entry(dev_cmp, ifindex)) != NULL)
 472                 ipq_issue_verdict(entry, NF_DROP);
 473 }
 474
 475 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 476
 477 static inline void
 478 ipq_rcv_skb(struct sk_buff *skb)
 479 {
 480         int status, type, pid, flags, nlmsglen, skblen;
 481         struct nlmsghdr *nlh;
 482
 483         skblen = skb->len;
 484         if (skblen < sizeof(*nlh))
 485                 return;
 486
 487         nlh = nlmsg_hdr(skb);
 488         nlmsglen = nlh->nlmsg_len;
 489         if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
 490                 return;
 491
 492         pid = nlh->nlmsg_pid;
 493         flags = nlh->nlmsg_flags;
 494
 495         if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
 496                 RCV_SKB_FAIL(-EINVAL);
 497
 498         if (flags & MSG_TRUNC)
 499                 RCV_SKB_FAIL(-ECOMM);
 500
 501         type = nlh->nlmsg_type;
 502         if (type < NLMSG_NOOP || type >= IPQM_MAX)
 503                 RCV_SKB_FAIL(-EINVAL);
 504
 505         if (type <= IPQM_BASE)
 506                 return;
 507
 508         if (security_netlink_recv(skb, CAP_NET_ADMIN))
 509                 RCV_SKB_FAIL(-EPERM);
 510
 511         write_lock_bh(&queue_lock);
 512
 513         if (peer_pid) {
 514                 if (peer_pid != pid) {
 515                         write_unlock_bh(&queue_lock);
 516                         RCV_SKB_FAIL(-EBUSY);
 517                 }
 518         } else {
 519                 net_enable_timestamp();
 520                 peer_pid = pid;
 521         }
 522
 523         write_unlock_bh(&queue_lock);
 524
 525         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 526                                   nlmsglen - NLMSG_LENGTH(0));
 527         if (status < 0)
 528                 RCV_SKB_FAIL(status);
 529
 530         if (flags & NLM_F_ACK)
 531                 netlink_ack(skb, nlh, 0);
 532         return;
 533 }
 534
 535 static void
 536 ipq_rcv_sk(struct sock *sk, int len)
 537 {
 538         struct sk_buff *skb;
 539         unsigned int qlen;
 540
 541         mutex_lock(&ipqnl_mutex);
 542
 543         for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
 544                 skb = skb_dequeue(&sk->sk_receive_queue);
 545                 ipq_rcv_skb(skb);
 546                 kfree_skb(skb);
 547         }
 548
 549         mutex_unlock(&ipqnl_mutex);
 550 }
 551
 552 static int
 553 ipq_rcv_dev_event(struct notifier_block *this,
 554                   unsigned long event, void *ptr)
 555 {
 556         struct net_device *dev = ptr;
 557
 558         if (dev->nd_net != &init_net)
 559                 return NOTIFY_DONE;
 560
 561         /* Drop any packets associated with the downed device */
 562         if (event == NETDEV_DOWN)
 563                 ipq_dev_drop(dev->ifindex);
 564         return NOTIFY_DONE;
 565 }
 566
 567 static struct notifier_block ipq_dev_notifier = {
 568         .notifier_call  = ipq_rcv_dev_event,
 569 };
 570
 571 static int
 572 ipq_rcv_nl_event(struct notifier_block *this,
 573                  unsigned long event, void *ptr)
 574 {
 575         struct netlink_notify *n = ptr;
 576
 577         if (event == NETLINK_URELEASE &&
 578             n->protocol == NETLINK_FIREWALL && n->pid) {
 579                 write_lock_bh(&queue_lock);
 580                 if ((n->net == &init_net) && (n->pid == peer_pid))
 581                         __ipq_reset();
 582                 write_unlock_bh(&queue_lock);
 583         }
 584         return NOTIFY_DONE;
 585 }
 586
 587 static struct notifier_block ipq_nl_notifier = {
 588         .notifier_call  = ipq_rcv_nl_event,
 589 };
 590
 591 static struct ctl_table_header *ipq_sysctl_header;
 592
 593 static ctl_table ipq_table[] = {
 594         {
 595                 .ctl_name       = NET_IPQ_QMAX,
 596                 .procname       = NET_IPQ_QMAX_NAME,
 597                 .data           = &queue_maxlen,
 598                 .maxlen         = sizeof(queue_maxlen),
 599                 .mode           = 0644,
 600                 .proc_handler   = proc_dointvec
 601         },
 602         { .ctl_name = 0 }
 603 };
 604
 605 static ctl_table ipq_dir_table[] = {
 606         {
 607                 .ctl_name       = NET_IPV4,
 608                 .procname       = "ipv4",
 609                 .mode           = 0555,
 610                 .child          = ipq_table
 611         },
 612         { .ctl_name = 0 }
 613 };
 614
 615 static ctl_table ipq_root_table[] = {
 616         {
 617                 .ctl_name       = CTL_NET,
 618                 .procname       = "net",
 619                 .mode           = 0555,
 620                 .child          = ipq_dir_table
 621         },
 622         { .ctl_name = 0 }
 623 };
 624
 625 #ifdef CONFIG_PROC_FS
 626 static int
 627 ipq_get_info(char *buffer, char **start, off_t offset, int length)
 628 {
 629         int len;
 630
 631         read_lock_bh(&queue_lock);
 632
 633         len = sprintf(buffer,
 634                       "Peer PID          : %d\n"
 635                       "Copy mode         : %hu\n"
 636                       "Copy range        : %u\n"
 637                       "Queue length      : %u\n"
 638                       "Queue max. length : %u\n"
 639                       "Queue dropped     : %u\n"
 640                       "Netlink dropped   : %u\n",
 641                       peer_pid,
 642                       copy_mode,
 643                       copy_range,
 644                       queue_total,
 645                       queue_maxlen,
 646                       queue_dropped,
 647                       queue_user_dropped);
 648
 649         read_unlock_bh(&queue_lock);
 650
 651         *start = buffer + offset;
 652         len -= offset;
 653         if (len > length)
 654                 len = length;
 655         else if (len < 0)
 656                 len = 0;
 657         return len;
 658 }
 659 #endif /* CONFIG_PROC_FS */
 660
 661 static struct nf_queue_handler nfqh = {
 662         .name   = "ip_queue",
 663         .outfn  = &ipq_enqueue_packet,
 664 };
 665
 666 static int __init ip_queue_init(void)
 667 {
 668         int status = -ENOMEM;
 669         struct proc_dir_entry *proc;
 670
 671         netlink_register_notifier(&ipq_nl_notifier);
 672         ipqnl = netlink_kernel_create(&init_net, NETLINK_FIREWALL, 0,
 673                                       ipq_rcv_sk, NULL, THIS_MODULE);
 674         if (ipqnl == NULL) {
 675                 printk(KERN_ERR "ip_queue: failed to create netlink socket\n");
 676                 goto cleanup_netlink_notifier;
 677         }
 678
 679         proc = proc_net_create(&init_net, IPQ_PROC_FS_NAME, 0, ipq_get_info);
 680         if (proc)
 681                 proc->owner = THIS_MODULE;
 682         else {
 683                 printk(KERN_ERR "ip_queue: failed to create proc entry\n");
 684                 goto cleanup_ipqnl;
 685         }
 686
 687         register_netdevice_notifier(&ipq_dev_notifier);
 688         ipq_sysctl_header = register_sysctl_table(ipq_root_table);
 689
 690         status = nf_register_queue_handler(PF_INET, &nfqh);
 691         if (status < 0) {
 692                 printk(KERN_ERR "ip_queue: failed to register queue handler\n");
 693                 goto cleanup_sysctl;
 694         }
 695         return status;
 696
 697 cleanup_sysctl:
 698         unregister_sysctl_table(ipq_sysctl_header);
 699         unregister_netdevice_notifier(&ipq_dev_notifier);
 700         proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 701 cleanup_ipqnl:
 702         sock_release(ipqnl->sk_socket);
 703         mutex_lock(&ipqnl_mutex);
 704         mutex_unlock(&ipqnl_mutex);
 705
 706 cleanup_netlink_notifier:
 707         netlink_unregister_notifier(&ipq_nl_notifier);
 708         return status;
 709 }
 710
 711 static void __exit ip_queue_fini(void)
 712 {
 713         nf_unregister_queue_handlers(&nfqh);
 714         synchronize_net();
 715         ipq_flush(NF_DROP);
 716
 717         unregister_sysctl_table(ipq_sysctl_header);
 718         unregister_netdevice_notifier(&ipq_dev_notifier);
 719         proc_net_remove(&init_net, IPQ_PROC_FS_NAME);
 720
 721         sock_release(ipqnl->sk_socket);
 722         mutex_lock(&ipqnl_mutex);
 723         mutex_unlock(&ipqnl_mutex);
 724
 725         netlink_unregister_notifier(&ipq_nl_notifier);
 726 }
 727
 728 MODULE_DESCRIPTION("IPv4 packet queue handler");
 729 MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
 730 MODULE_LICENSE("GPL");
 731
 732 module_init(ip_queue_init);
 733 module_exit(ip_queue_fini);