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  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * 2000-03-27: Simplified code (thanks to Andi Kleen for clues).
  12  * 2000-05-20: Fixed notifier problems (following Miguel Freitas' report).
  13  * 2000-06-19: Fixed so nfmark is copied to metadata (reported by Sebastian
  14  *             Zander).
  15  * 2000-08-01: Added Nick Williams' MAC support.
  16  * 2002-06-25: Code cleanup.
  17  *
  18  */
  19 #include <linux/module.h>
  20 #include <linux/skbuff.h>
  21 #include <linux/init.h>
  22 #include <linux/ip.h>
  23 #include <linux/notifier.h>
  24 #include <linux/netdevice.h>
  25 #include <linux/netfilter.h>
  26 #include <linux/netfilter_ipv4/ip_queue.h>
  27 #include <linux/netfilter_ipv4/ip_tables.h>
  28 #include <linux/netlink.h>
  29 #include <linux/spinlock.h>
  30 #include <linux/sysctl.h>
  31 #include <linux/proc_fs.h>
  32 #include <linux/security.h>
  33 #include <net/sock.h>
  34 #include <net/route.h>
  35
  36 #define IPQ_QMAX_DEFAULT 1024
  37 #define IPQ_PROC_FS_NAME "ip_queue"
  38 #define NET_IPQ_QMAX 2088
  39 #define NET_IPQ_QMAX_NAME "ip_queue_maxlen"
  40
  41 struct ipq_rt_info {
  42         __u8 tos;
  43         __u32 daddr;
  44         __u32 saddr;
  45 };
  46
  47 struct ipq_queue_entry {
  48         struct list_head list;
  49         struct nf_info *info;
  50         struct sk_buff *skb;
  51         struct ipq_rt_info rt_info;
  52 };
  53
  54 typedef int (*ipq_cmpfn)(struct ipq_queue_entry *, unsigned long);
  55
  56 static unsigned char copy_mode = IPQ_COPY_NONE;
  57 static unsigned int queue_maxlen = IPQ_QMAX_DEFAULT;
  58 static DEFINE_RWLOCK(queue_lock);
  59 static int peer_pid;
  60 static unsigned int copy_range;
  61 static unsigned int queue_total;
  62 static struct sock *ipqnl;
  63 static LIST_HEAD(queue_list);
  64 static DECLARE_MUTEX(ipqnl_sem);
  65
  66 static void
  67 ipq_issue_verdict(struct ipq_queue_entry *entry, int verdict)
  68 {
  69         nf_reinject(entry->skb, entry->info, verdict);
  70         kfree(entry);
  71 }
  72
  73 static inline int
  74 __ipq_enqueue_entry(struct ipq_queue_entry *entry)
  75 {
  76        if (queue_total >= queue_maxlen) {
  77                if (net_ratelimit())
  78                        printk(KERN_WARNING "ip_queue: full at %d entries, "
  79                               "dropping packet(s).\n", queue_total);
  80                return -ENOSPC;
  81        }
  82        list_add(&entry->list, &queue_list);
  83        queue_total++;
  84        return 0;
  85 }
  86
  87 /*
  88  * Find and return a queued entry matched by cmpfn, or return the last
  89  * entry if cmpfn is NULL.
  90  */
  91 static inline struct ipq_queue_entry *
  92 __ipq_find_entry(ipq_cmpfn cmpfn, unsigned long data)
  93 {
  94         struct list_head *p;
  95
  96         list_for_each_prev(p, &queue_list) {
  97                 struct ipq_queue_entry *entry = (struct ipq_queue_entry *)p;
  98
  99                 if (!cmpfn || cmpfn(entry, data))
 100                         return entry;
 101         }
 102         return NULL;
 103 }
 104
 105 static inline void
 106 __ipq_dequeue_entry(struct ipq_queue_entry *entry)
 107 {
 108         list_del(&entry->list);
 109         queue_total--;
 110 }
 111
 112 static inline struct ipq_queue_entry *
 113 __ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 114 {
 115         struct ipq_queue_entry *entry;
 116
 117         entry = __ipq_find_entry(cmpfn, data);
 118         if (entry == NULL)
 119                 return NULL;
 120
 121         __ipq_dequeue_entry(entry);
 122         return entry;
 123 }
 124
 125
 126 static inline void
 127 __ipq_flush(int verdict)
 128 {
 129         struct ipq_queue_entry *entry;
 130
 131         while ((entry = __ipq_find_dequeue_entry(NULL, 0)))
 132                 ipq_issue_verdict(entry, verdict);
 133 }
 134
 135 static inline int
 136 __ipq_set_mode(unsigned char mode, unsigned int range)
 137 {
 138         int status = 0;
 139
 140         switch(mode) {
 141         case IPQ_COPY_NONE:
 142         case IPQ_COPY_META:
 143                 copy_mode = mode;
 144                 copy_range = 0;
 145                 break;
 146
 147         case IPQ_COPY_PACKET:
 148                 copy_mode = mode;
 149                 copy_range = range;
 150                 if (copy_range > 0xFFFF)
 151                         copy_range = 0xFFFF;
 152                 break;
 153
 154         default:
 155                 status = -EINVAL;
 156
 157         }
 158         return status;
 159 }
 160
 161 static inline void
 162 __ipq_reset(void)
 163 {
 164         peer_pid = 0;
 165         net_disable_timestamp();
 166         __ipq_set_mode(IPQ_COPY_NONE, 0);
 167         __ipq_flush(NF_DROP);
 168 }
 169
 170 static struct ipq_queue_entry *
 171 ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 172 {
 173         struct ipq_queue_entry *entry;
 174
 175         write_lock_bh(&queue_lock);
 176         entry = __ipq_find_dequeue_entry(cmpfn, data);
 177         write_unlock_bh(&queue_lock);
 178         return entry;
 179 }
 180
 181 static void
 182 ipq_flush(int verdict)
 183 {
 184         write_lock_bh(&queue_lock);
 185         __ipq_flush(verdict);
 186         write_unlock_bh(&queue_lock);
 187 }
 188
 189 static struct sk_buff *
 190 ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 191 {
 192         unsigned char *old_tail;
 193         size_t size = 0;
 194         size_t data_len = 0;
 195         struct sk_buff *skb;
 196         struct ipq_packet_msg *pmsg;
 197         struct nlmsghdr *nlh;
 198
 199         read_lock_bh(&queue_lock);
 200
 201         switch (copy_mode) {
 202         case IPQ_COPY_META:
 203         case IPQ_COPY_NONE:
 204                 size = NLMSG_SPACE(sizeof(*pmsg));
 205                 data_len = 0;
 206                 break;
 207
 208         case IPQ_COPY_PACKET:
 209                 if (copy_range == 0 || copy_range > entry->skb->len)
 210                         data_len = entry->skb->len;
 211                 else
 212                         data_len = copy_range;
 213
 214                 size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
 215                 break;
 216
 217         default:
 218                 *errp = -EINVAL;
 219                 read_unlock_bh(&queue_lock);
 220                 return NULL;
 221         }
 222
 223         read_unlock_bh(&queue_lock);
 224
 225         skb = alloc_skb(size, GFP_ATOMIC);
 226         if (!skb)
 227                 goto nlmsg_failure;
 228
 229         old_tail= skb->tail;
 230         nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
 231         pmsg = NLMSG_DATA(nlh);
 232         memset(pmsg, 0, sizeof(*pmsg));
 233
 234         pmsg->packet_id       = (unsigned long )entry;
 235         pmsg->data_len        = data_len;
 236         pmsg->timestamp_sec   = entry->skb->stamp.tv_sec;
 237         pmsg->timestamp_usec  = entry->skb->stamp.tv_usec;
 238         pmsg->mark            = entry->skb->nfmark;
 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                 if (entry->skb->dev->hard_header_parse)
 255                         pmsg->hw_addrlen =
 256                                 entry->skb->dev->hard_header_parse(entry->skb,
 257                                                                    pmsg->hw_addr);
 258         }
 259
 260         if (data_len)
 261                 if (skb_copy_bits(entry->skb, 0, pmsg->payload, data_len))
 262                         BUG();
 263
 264         nlh->nlmsg_len = skb->tail - old_tail;
 265         return skb;
 266
 267 nlmsg_failure:
 268         if (skb)
 269                 kfree_skb(skb);
 270         *errp = -EINVAL;
 271         printk(KERN_ERR "ip_queue: error creating packet message\n");
 272         return NULL;
 273 }
 274
 275 static int
 276 ipq_enqueue_packet(struct sk_buff *skb, struct nf_info *info, 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         if (entry->info->hook == NF_IP_LOCAL_OUT) {
 295                 struct iphdr *iph = skb->nh.iph;
 296
 297                 entry->rt_info.tos = iph->tos;
 298                 entry->rt_info.daddr = iph->daddr;
 299                 entry->rt_info.saddr = iph->saddr;
 300         }
 301
 302         nskb = ipq_build_packet_message(entry, &status);
 303         if (nskb == NULL)
 304                 goto err_out_free;
 305
 306         write_lock_bh(&queue_lock);
 307
 308         if (!peer_pid)
 309                 goto err_out_free_nskb;
 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                 goto err_out_unlock;
 315
 316         status = __ipq_enqueue_entry(entry);
 317         if (status < 0)
 318                 goto err_out_unlock;
 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                 skb_trim(e->skb, v->data_len);
 345         else if (diff > 0) {
 346                 if (v->data_len > 0xFFFF)
 347                         return -EINVAL;
 348                 if (diff > skb_tailroom(e->skb)) {
 349                         struct sk_buff *newskb;
 350
 351                         newskb = skb_copy_expand(e->skb,
 352                                                  skb_headroom(e->skb),
 353                                                  diff,
 354                                                  GFP_ATOMIC);
 355                         if (newskb == NULL) {
 356                                 printk(KERN_WARNING "ip_queue: OOM "
 357                                       "in mangle, dropping packet\n");
 358                                 return -ENOMEM;
 359                         }
 360                         if (e->skb->sk)
 361                                 skb_set_owner_w(newskb, e->skb->sk);
 362                         kfree_skb(e->skb);
 363                         e->skb = newskb;
 364                 }
 365                 skb_put(e->skb, diff);
 366         }
 367         if (!skb_ip_make_writable(&e->skb, v->data_len))
 368                 return -ENOMEM;
 369         memcpy(e->skb->data, v->payload, v->data_len);
 370         e->skb->nfcache |= NFC_ALTERED;
 371
 372         /*
 373          * Extra routing may needed on local out, as the QUEUE target never
 374          * returns control to the table.
 375          */
 376         if (e->info->hook == NF_IP_LOCAL_OUT) {
 377                 struct iphdr *iph = e->skb->nh.iph;
 378
 379                 if (!(iph->tos == e->rt_info.tos
 380                       && iph->daddr == e->rt_info.daddr
 381                       && iph->saddr == e->rt_info.saddr))
 382                         return ip_route_me_harder(&e->skb);
 383         }
 384         return 0;
 385 }
 386
 387 static inline int
 388 id_cmp(struct ipq_queue_entry *e, unsigned long id)
 389 {
 390         return (id == (unsigned long )e);
 391 }
 392
 393 static int
 394 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
 395 {
 396         struct ipq_queue_entry *entry;
 397
 398         if (vmsg->value > NF_MAX_VERDICT)
 399                 return -EINVAL;
 400
 401         entry = ipq_find_dequeue_entry(id_cmp, vmsg->id);
 402         if (entry == NULL)
 403                 return -ENOENT;
 404         else {
 405                 int verdict = vmsg->value;
 406
 407                 if (vmsg->data_len && vmsg->data_len == len)
 408                         if (ipq_mangle_ipv4(vmsg, entry) < 0)
 409                                 verdict = NF_DROP;
 410
 411                 ipq_issue_verdict(entry, verdict);
 412                 return 0;
 413         }
 414 }
 415
 416 static int
 417 ipq_set_mode(unsigned char mode, unsigned int range)
 418 {
 419         int status;
 420
 421         write_lock_bh(&queue_lock);
 422         status = __ipq_set_mode(mode, range);
 423         write_unlock_bh(&queue_lock);
 424         return status;
 425 }
 426
 427 static int
 428 ipq_receive_peer(struct ipq_peer_msg *pmsg,
 429                  unsigned char type, unsigned int len)
 430 {
 431         int status = 0;
 432
 433         if (len < sizeof(*pmsg))
 434                 return -EINVAL;
 435
 436         switch (type) {
 437         case IPQM_MODE:
 438                 status = ipq_set_mode(pmsg->msg.mode.value,
 439                                       pmsg->msg.mode.range);
 440                 break;
 441
 442         case IPQM_VERDICT:
 443                 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
 444                         status = -EINVAL;
 445                 else
 446                         status = ipq_set_verdict(&pmsg->msg.verdict,
 447                                                  len - sizeof(*pmsg));
 448                         break;
 449         default:
 450                 status = -EINVAL;
 451         }
 452         return status;
 453 }
 454
 455 static int
 456 dev_cmp(struct ipq_queue_entry *entry, unsigned long ifindex)
 457 {
 458         if (entry->info->indev)
 459                 if (entry->info->indev->ifindex == ifindex)
 460                         return 1;
 461
 462         if (entry->info->outdev)
 463                 if (entry->info->outdev->ifindex == ifindex)
 464                         return 1;
 465
 466         return 0;
 467 }
 468
 469 static void
 470 ipq_dev_drop(int ifindex)
 471 {
 472         struct ipq_queue_entry *entry;
 473
 474         while ((entry = ipq_find_dequeue_entry(dev_cmp, ifindex)) != NULL)
 475                 ipq_issue_verdict(entry, NF_DROP);
 476 }
 477
 478 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 479
 480 static inline void
 481 ipq_rcv_skb(struct sk_buff *skb)
 482 {
 483         int status, type, pid, flags, nlmsglen, skblen;
 484         struct nlmsghdr *nlh;
 485
 486         skblen = skb->len;
 487         if (skblen < sizeof(*nlh))
 488                 return;
 489
 490         nlh = (struct nlmsghdr *)skb->data;
 491         nlmsglen = nlh->nlmsg_len;
 492         if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
 493                 return;
 494
 495         pid = nlh->nlmsg_pid;
 496         flags = nlh->nlmsg_flags;
 497
 498         if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
 499                 RCV_SKB_FAIL(-EINVAL);
 500
 501         if (flags & MSG_TRUNC)
 502                 RCV_SKB_FAIL(-ECOMM);
 503
 504         type = nlh->nlmsg_type;
 505         if (type < NLMSG_NOOP || type >= IPQM_MAX)
 506                 RCV_SKB_FAIL(-EINVAL);
 507
 508         if (type <= IPQM_BASE)
 509                 return;
 510
 511         if (security_netlink_recv(skb))
 512                 RCV_SKB_FAIL(-EPERM);
 513
 514         write_lock_bh(&queue_lock);
 515
 516         if (peer_pid) {
 517                 if (peer_pid != pid) {
 518                         write_unlock_bh(&queue_lock);
 519                         RCV_SKB_FAIL(-EBUSY);
 520                 }
 521         } else {
 522                 net_enable_timestamp();
 523                 peer_pid = pid;
 524         }
 525
 526         write_unlock_bh(&queue_lock);
 527
 528         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 529                                   skblen - NLMSG_LENGTH(0));
 530         if (status < 0)
 531                 RCV_SKB_FAIL(status);
 532
 533         if (flags & NLM_F_ACK)
 534                 netlink_ack(skb, nlh, 0);
 535         return;
 536 }
 537
 538 static void
 539 ipq_rcv_sk(struct sock *sk, int len)
 540 {
 541         do {
 542                 struct sk_buff *skb;
 543
 544                 if (down_trylock(&ipqnl_sem))
 545                         return;
 546
 547                 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
 548                         ipq_rcv_skb(skb);
 549                         kfree_skb(skb);
 550                 }
 551
 552                 up(&ipqnl_sem);
 553
 554         } while (ipqnl && ipqnl->sk_receive_queue.qlen);
 555 }
 556
 557 static int
 558 ipq_rcv_dev_event(struct notifier_block *this,
 559                   unsigned long event, void *ptr)
 560 {
 561         struct net_device *dev = ptr;
 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->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                       peer_pid,
 642                       copy_mode,
 643                       copy_range,
 644                       queue_total,
 645                       queue_maxlen);
 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 int
 660 init_or_cleanup(int init)
 661 {
 662         int status = -ENOMEM;
 663         struct proc_dir_entry *proc;
 664
 665         if (!init)
 666                 goto cleanup;
 667
 668         netlink_register_notifier(&ipq_nl_notifier);
 669         ipqnl = netlink_kernel_create(NETLINK_FIREWALL, ipq_rcv_sk);
 670         if (ipqnl == NULL) {
 671                 printk(KERN_ERR "ip_queue: failed to create netlink socket\n");
 672                 goto cleanup_netlink_notifier;
 673         }
 674
 675         proc = proc_net_create(IPQ_PROC_FS_NAME, 0, ipq_get_info);
 676         if (proc)
 677                 proc->owner = THIS_MODULE;
 678         else {
 679                 printk(KERN_ERR "ip_queue: failed to create proc entry\n");
 680                 goto cleanup_ipqnl;
 681         }
 682
 683         register_netdevice_notifier(&ipq_dev_notifier);
 684         ipq_sysctl_header = register_sysctl_table(ipq_root_table, 0);
 685
 686         status = nf_register_queue_handler(PF_INET, ipq_enqueue_packet, NULL);
 687         if (status < 0) {
 688                 printk(KERN_ERR "ip_queue: failed to register queue handler\n");
 689                 goto cleanup_sysctl;
 690         }
 691         return status;
 692
 693 cleanup:
 694         nf_unregister_queue_handler(PF_INET);
 695         synchronize_net();
 696         ipq_flush(NF_DROP);
 697
 698 cleanup_sysctl:
 699         unregister_sysctl_table(ipq_sysctl_header);
 700         unregister_netdevice_notifier(&ipq_dev_notifier);
 701         proc_net_remove(IPQ_PROC_FS_NAME);
 702
 703 cleanup_ipqnl:
 704         sock_release(ipqnl->sk_socket);
 705         down(&ipqnl_sem);
 706         up(&ipqnl_sem);
 707
 708 cleanup_netlink_notifier:
 709         netlink_unregister_notifier(&ipq_nl_notifier);
 710         return status;
 711 }
 712
 713 static int __init init(void)
 714 {
 715
 716         return init_or_cleanup(1);
 717 }
 718
 719 static void __exit fini(void)
 720 {
 721         init_or_cleanup(0);
 722 }
 723
 724 MODULE_DESCRIPTION("IPv4 packet queue handler");
 725 MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
 726 MODULE_LICENSE("GPL");
 727
 728 module_init(init);
 729 module_exit(fini);