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  * 2000-03-27: Simplified code (thanks to Andi Kleen for clues).
  13  * 2000-05-20: Fixed notifier problems (following Miguel Freitas' report).
  14  * 2000-06-19: Fixed so nfmark is copied to metadata (reported by Sebastian
  15  *             Zander).
  16  * 2000-08-01: Added Nick Williams' MAC support.
  17  * 2002-06-25: Code cleanup.
  18  * 2005-01-10: Added /proc counter for dropped packets; fixed so
  19  *             packets aren't delivered to user space if they're going
  20  *             to be dropped.
  21  * 2005-05-26: local_bh_{disable,enable} around nf_reinject (Harald Welte)
  22  *
  23  */
  24 #include <linux/module.h>
  25 #include <linux/skbuff.h>
  26 #include <linux/init.h>
  27 #include <linux/ip.h>
  28 #include <linux/notifier.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/netfilter.h>
  31 #include <linux/netfilter_ipv4/ip_queue.h>
  32 #include <linux/netfilter_ipv4/ip_tables.h>
  33 #include <linux/netlink.h>
  34 #include <linux/spinlock.h>
  35 #include <linux/sysctl.h>
  36 #include <linux/proc_fs.h>
  37 #include <linux/security.h>
  38 #include <net/sock.h>
  39 #include <net/route.h>
  40
  41 #define IPQ_QMAX_DEFAULT 1024
  42 #define IPQ_PROC_FS_NAME "ip_queue"
  43 #define NET_IPQ_QMAX 2088
  44 #define NET_IPQ_QMAX_NAME "ip_queue_maxlen"
  45
  46 struct ipq_rt_info {
  47         __u8 tos;
  48         __u32 daddr;
  49         __u32 saddr;
  50 };
  51
  52 struct ipq_queue_entry {
  53         struct list_head list;
  54         struct nf_info *info;
  55         struct sk_buff *skb;
  56         struct ipq_rt_info rt_info;
  57 };
  58
  59 typedef int (*ipq_cmpfn)(struct ipq_queue_entry *, unsigned long);
  60
  61 static unsigned char copy_mode = IPQ_COPY_NONE;
  62 static unsigned int queue_maxlen = IPQ_QMAX_DEFAULT;
  63 static DEFINE_RWLOCK(queue_lock);
  64 static int peer_pid;
  65 static unsigned int copy_range;
  66 static unsigned int queue_total;
  67 static unsigned int queue_dropped = 0;
  68 static unsigned int queue_user_dropped = 0;
  69 static struct sock *ipqnl;
  70 static LIST_HEAD(queue_list);
  71 static DECLARE_MUTEX(ipqnl_sem);
  72
  73 static void
  74 ipq_issue_verdict(struct ipq_queue_entry *entry, int verdict)
  75 {
  76         /* TCP input path (and probably other bits) assume to be called
  77          * from softirq context, not from syscall, like ipq_issue_verdict is
  78          * called.  TCP input path deadlocks with locks taken from timer
  79          * softirq, e.g.  We therefore emulate this by local_bh_disable() */
  80
  81         local_bh_disable();
  82         nf_reinject(entry->skb, entry->info, verdict);
  83         local_bh_enable();
  84
  85         kfree(entry);
  86 }
  87
  88 static inline void
  89 __ipq_enqueue_entry(struct ipq_queue_entry *entry)
  90 {
  91        list_add(&entry->list, &queue_list);
  92        queue_total++;
  93 }
  94
  95 /*
  96  * Find and return a queued entry matched by cmpfn, or return the last
  97  * entry if cmpfn is NULL.
  98  */
  99 static inline struct ipq_queue_entry *
 100 __ipq_find_entry(ipq_cmpfn cmpfn, unsigned long data)
 101 {
 102         struct list_head *p;
 103
 104         list_for_each_prev(p, &queue_list) {
 105                 struct ipq_queue_entry *entry = (struct ipq_queue_entry *)p;
 106
 107                 if (!cmpfn || cmpfn(entry, data))
 108                         return entry;
 109         }
 110         return NULL;
 111 }
 112
 113 static inline void
 114 __ipq_dequeue_entry(struct ipq_queue_entry *entry)
 115 {
 116         list_del(&entry->list);
 117         queue_total--;
 118 }
 119
 120 static inline struct ipq_queue_entry *
 121 __ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 122 {
 123         struct ipq_queue_entry *entry;
 124
 125         entry = __ipq_find_entry(cmpfn, data);
 126         if (entry == NULL)
 127                 return NULL;
 128
 129         __ipq_dequeue_entry(entry);
 130         return entry;
 131 }
 132
 133
 134 static inline void
 135 __ipq_flush(int verdict)
 136 {
 137         struct ipq_queue_entry *entry;
 138
 139         while ((entry = __ipq_find_dequeue_entry(NULL, 0)))
 140                 ipq_issue_verdict(entry, verdict);
 141 }
 142
 143 static inline int
 144 __ipq_set_mode(unsigned char mode, unsigned int range)
 145 {
 146         int status = 0;
 147
 148         switch(mode) {
 149         case IPQ_COPY_NONE:
 150         case IPQ_COPY_META:
 151                 copy_mode = mode;
 152                 copy_range = 0;
 153                 break;
 154
 155         case IPQ_COPY_PACKET:
 156                 copy_mode = mode;
 157                 copy_range = range;
 158                 if (copy_range > 0xFFFF)
 159                         copy_range = 0xFFFF;
 160                 break;
 161
 162         default:
 163                 status = -EINVAL;
 164
 165         }
 166         return status;
 167 }
 168
 169 static inline void
 170 __ipq_reset(void)
 171 {
 172         peer_pid = 0;
 173         net_disable_timestamp();
 174         __ipq_set_mode(IPQ_COPY_NONE, 0);
 175         __ipq_flush(NF_DROP);
 176 }
 177
 178 static struct ipq_queue_entry *
 179 ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 180 {
 181         struct ipq_queue_entry *entry;
 182
 183         write_lock_bh(&queue_lock);
 184         entry = __ipq_find_dequeue_entry(cmpfn, data);
 185         write_unlock_bh(&queue_lock);
 186         return entry;
 187 }
 188
 189 static void
 190 ipq_flush(int verdict)
 191 {
 192         write_lock_bh(&queue_lock);
 193         __ipq_flush(verdict);
 194         write_unlock_bh(&queue_lock);
 195 }
 196
 197 static struct sk_buff *
 198 ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 199 {
 200         unsigned char *old_tail;
 201         size_t size = 0;
 202         size_t data_len = 0;
 203         struct sk_buff *skb;
 204         struct ipq_packet_msg *pmsg;
 205         struct nlmsghdr *nlh;
 206
 207         read_lock_bh(&queue_lock);
 208
 209         switch (copy_mode) {
 210         case IPQ_COPY_META:
 211         case IPQ_COPY_NONE:
 212                 size = NLMSG_SPACE(sizeof(*pmsg));
 213                 data_len = 0;
 214                 break;
 215
 216         case IPQ_COPY_PACKET:
 217                 if (copy_range == 0 || copy_range > entry->skb->len)
 218                         data_len = entry->skb->len;
 219                 else
 220                         data_len = copy_range;
 221
 222                 size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
 223                 break;
 224
 225         default:
 226                 *errp = -EINVAL;
 227                 read_unlock_bh(&queue_lock);
 228                 return NULL;
 229         }
 230
 231         read_unlock_bh(&queue_lock);
 232
 233         skb = alloc_skb(size, GFP_ATOMIC);
 234         if (!skb)
 235                 goto nlmsg_failure;
 236
 237         old_tail= skb->tail;
 238         nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
 239         pmsg = NLMSG_DATA(nlh);
 240         memset(pmsg, 0, sizeof(*pmsg));
 241
 242         pmsg->packet_id       = (unsigned long )entry;
 243         pmsg->data_len        = data_len;
 244         pmsg->timestamp_sec   = entry->skb->stamp.tv_sec;
 245         pmsg->timestamp_usec  = entry->skb->stamp.tv_usec;
 246         pmsg->mark            = entry->skb->nfmark;
 247         pmsg->hook            = entry->info->hook;
 248         pmsg->hw_protocol     = entry->skb->protocol;
 249
 250         if (entry->info->indev)
 251                 strcpy(pmsg->indev_name, entry->info->indev->name);
 252         else
 253                 pmsg->indev_name[0] = '\0';
 254
 255         if (entry->info->outdev)
 256                 strcpy(pmsg->outdev_name, entry->info->outdev->name);
 257         else
 258                 pmsg->outdev_name[0] = '\0';
 259
 260         if (entry->info->indev && entry->skb->dev) {
 261                 pmsg->hw_type = entry->skb->dev->type;
 262                 if (entry->skb->dev->hard_header_parse)
 263                         pmsg->hw_addrlen =
 264                                 entry->skb->dev->hard_header_parse(entry->skb,
 265                                                                    pmsg->hw_addr);
 266         }
 267
 268         if (data_len)
 269                 if (skb_copy_bits(entry->skb, 0, pmsg->payload, data_len))
 270                         BUG();
 271
 272         nlh->nlmsg_len = skb->tail - old_tail;
 273         return skb;
 274
 275 nlmsg_failure:
 276         if (skb)
 277                 kfree_skb(skb);
 278         *errp = -EINVAL;
 279         printk(KERN_ERR "ip_queue: error creating packet message\n");
 280         return NULL;
 281 }
 282
 283 static int
 284 ipq_enqueue_packet(struct sk_buff *skb, struct nf_info *info, void *data)
 285 {
 286         int status = -EINVAL;
 287         struct sk_buff *nskb;
 288         struct ipq_queue_entry *entry;
 289
 290         if (copy_mode == IPQ_COPY_NONE)
 291                 return -EAGAIN;
 292
 293         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 294         if (entry == NULL) {
 295                 printk(KERN_ERR "ip_queue: OOM in ipq_enqueue_packet()\n");
 296                 return -ENOMEM;
 297         }
 298
 299         entry->info = info;
 300         entry->skb = skb;
 301
 302         if (entry->info->hook == NF_IP_LOCAL_OUT) {
 303                 struct iphdr *iph = skb->nh.iph;
 304
 305                 entry->rt_info.tos = iph->tos;
 306                 entry->rt_info.daddr = iph->daddr;
 307                 entry->rt_info.saddr = iph->saddr;
 308         }
 309
 310         nskb = ipq_build_packet_message(entry, &status);
 311         if (nskb == NULL)
 312                 goto err_out_free;
 313
 314         write_lock_bh(&queue_lock);
 315
 316         if (!peer_pid)
 317                 goto err_out_free_nskb;
 318
 319         if (queue_total >= queue_maxlen) {
 320                 queue_dropped++;
 321                 status = -ENOSPC;
 322                 if (net_ratelimit())
 323                           printk (KERN_WARNING "ip_queue: full at %d entries, "
 324                                   "dropping packets(s). Dropped: %d\n", queue_total,
 325                                   queue_dropped);
 326                 goto err_out_free_nskb;
 327         }
 328
 329         /* netlink_unicast will either free the nskb or attach it to a socket */
 330         status = netlink_unicast(ipqnl, nskb, peer_pid, MSG_DONTWAIT);
 331         if (status < 0) {
 332                 queue_user_dropped++;
 333                 goto err_out_unlock;
 334         }
 335
 336         __ipq_enqueue_entry(entry);
 337
 338         write_unlock_bh(&queue_lock);
 339         return status;
 340
 341 err_out_free_nskb:
 342         kfree_skb(nskb);
 343
 344 err_out_unlock:
 345         write_unlock_bh(&queue_lock);
 346
 347 err_out_free:
 348         kfree(entry);
 349         return status;
 350 }
 351
 352 static int
 353 ipq_mangle_ipv4(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
 354 {
 355         int diff;
 356         struct iphdr *user_iph = (struct iphdr *)v->payload;
 357
 358         if (v->data_len < sizeof(*user_iph))
 359                 return 0;
 360         diff = v->data_len - e->skb->len;
 361         if (diff < 0)
 362                 skb_trim(e->skb, v->data_len);
 363         else if (diff > 0) {
 364                 if (v->data_len > 0xFFFF)
 365                         return -EINVAL;
 366                 if (diff > skb_tailroom(e->skb)) {
 367                         struct sk_buff *newskb;
 368
 369                         newskb = skb_copy_expand(e->skb,
 370                                                  skb_headroom(e->skb),
 371                                                  diff,
 372                                                  GFP_ATOMIC);
 373                         if (newskb == NULL) {
 374                                 printk(KERN_WARNING "ip_queue: OOM "
 375                                       "in mangle, dropping packet\n");
 376                                 return -ENOMEM;
 377                         }
 378                         if (e->skb->sk)
 379                                 skb_set_owner_w(newskb, e->skb->sk);
 380                         kfree_skb(e->skb);
 381                         e->skb = newskb;
 382                 }
 383                 skb_put(e->skb, diff);
 384         }
 385         if (!skb_ip_make_writable(&e->skb, v->data_len))
 386                 return -ENOMEM;
 387         memcpy(e->skb->data, v->payload, v->data_len);
 388         e->skb->nfcache |= NFC_ALTERED;
 389
 390         /*
 391          * Extra routing may needed on local out, as the QUEUE target never
 392          * returns control to the table.
 393          */
 394         if (e->info->hook == NF_IP_LOCAL_OUT) {
 395                 struct iphdr *iph = e->skb->nh.iph;
 396
 397                 if (!(iph->tos == e->rt_info.tos
 398                       && iph->daddr == e->rt_info.daddr
 399                       && iph->saddr == e->rt_info.saddr))
 400                         return ip_route_me_harder(&e->skb);
 401         }
 402         return 0;
 403 }
 404
 405 static inline int
 406 id_cmp(struct ipq_queue_entry *e, unsigned long id)
 407 {
 408         return (id == (unsigned long )e);
 409 }
 410
 411 static int
 412 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
 413 {
 414         struct ipq_queue_entry *entry;
 415
 416         if (vmsg->value > NF_MAX_VERDICT)
 417                 return -EINVAL;
 418
 419         entry = ipq_find_dequeue_entry(id_cmp, vmsg->id);
 420         if (entry == NULL)
 421                 return -ENOENT;
 422         else {
 423                 int verdict = vmsg->value;
 424
 425                 if (vmsg->data_len && vmsg->data_len == len)
 426                         if (ipq_mangle_ipv4(vmsg, entry) < 0)
 427                                 verdict = NF_DROP;
 428
 429                 ipq_issue_verdict(entry, verdict);
 430                 return 0;
 431         }
 432 }
 433
 434 static int
 435 ipq_set_mode(unsigned char mode, unsigned int range)
 436 {
 437         int status;
 438
 439         write_lock_bh(&queue_lock);
 440         status = __ipq_set_mode(mode, range);
 441         write_unlock_bh(&queue_lock);
 442         return status;
 443 }
 444
 445 static int
 446 ipq_receive_peer(struct ipq_peer_msg *pmsg,
 447                  unsigned char type, unsigned int len)
 448 {
 449         int status = 0;
 450
 451         if (len < sizeof(*pmsg))
 452                 return -EINVAL;
 453
 454         switch (type) {
 455         case IPQM_MODE:
 456                 status = ipq_set_mode(pmsg->msg.mode.value,
 457                                       pmsg->msg.mode.range);
 458                 break;
 459
 460         case IPQM_VERDICT:
 461                 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
 462                         status = -EINVAL;
 463                 else
 464                         status = ipq_set_verdict(&pmsg->msg.verdict,
 465                                                  len - sizeof(*pmsg));
 466                         break;
 467         default:
 468                 status = -EINVAL;
 469         }
 470         return status;
 471 }
 472
 473 static int
 474 dev_cmp(struct ipq_queue_entry *entry, unsigned long ifindex)
 475 {
 476         if (entry->info->indev)
 477                 if (entry->info->indev->ifindex == ifindex)
 478                         return 1;
 479
 480         if (entry->info->outdev)
 481                 if (entry->info->outdev->ifindex == ifindex)
 482                         return 1;
 483
 484         return 0;
 485 }
 486
 487 static void
 488 ipq_dev_drop(int ifindex)
 489 {
 490         struct ipq_queue_entry *entry;
 491
 492         while ((entry = ipq_find_dequeue_entry(dev_cmp, ifindex)) != NULL)
 493                 ipq_issue_verdict(entry, NF_DROP);
 494 }
 495
 496 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 497
 498 static inline void
 499 ipq_rcv_skb(struct sk_buff *skb)
 500 {
 501         int status, type, pid, flags, nlmsglen, skblen;
 502         struct nlmsghdr *nlh;
 503
 504         skblen = skb->len;
 505         if (skblen < sizeof(*nlh))
 506                 return;
 507
 508         nlh = (struct nlmsghdr *)skb->data;
 509         nlmsglen = nlh->nlmsg_len;
 510         if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
 511                 return;
 512
 513         pid = nlh->nlmsg_pid;
 514         flags = nlh->nlmsg_flags;
 515
 516         if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
 517                 RCV_SKB_FAIL(-EINVAL);
 518
 519         if (flags & MSG_TRUNC)
 520                 RCV_SKB_FAIL(-ECOMM);
 521
 522         type = nlh->nlmsg_type;
 523         if (type < NLMSG_NOOP || type >= IPQM_MAX)
 524                 RCV_SKB_FAIL(-EINVAL);
 525
 526         if (type <= IPQM_BASE)
 527                 return;
 528
 529         if (security_netlink_recv(skb))
 530                 RCV_SKB_FAIL(-EPERM);
 531
 532         write_lock_bh(&queue_lock);
 533
 534         if (peer_pid) {
 535                 if (peer_pid != pid) {
 536                         write_unlock_bh(&queue_lock);
 537                         RCV_SKB_FAIL(-EBUSY);
 538                 }
 539         } else {
 540                 net_enable_timestamp();
 541                 peer_pid = pid;
 542         }
 543
 544         write_unlock_bh(&queue_lock);
 545
 546         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 547                                   skblen - NLMSG_LENGTH(0));
 548         if (status < 0)
 549                 RCV_SKB_FAIL(status);
 550
 551         if (flags & NLM_F_ACK)
 552                 netlink_ack(skb, nlh, 0);
 553         return;
 554 }
 555
 556 static void
 557 ipq_rcv_sk(struct sock *sk, int len)
 558 {
 559         struct sk_buff *skb;
 560         unsigned int qlen;
 561
 562         down(&ipqnl_sem);
 563
 564         for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
 565                 skb = skb_dequeue(&sk->sk_receive_queue);
 566                 ipq_rcv_skb(skb);
 567                 kfree_skb(skb);
 568         }
 569
 570         up(&ipqnl_sem);
 571 }
 572
 573 static int
 574 ipq_rcv_dev_event(struct notifier_block *this,
 575                   unsigned long event, void *ptr)
 576 {
 577         struct net_device *dev = ptr;
 578
 579         /* Drop any packets associated with the downed device */
 580         if (event == NETDEV_DOWN)
 581                 ipq_dev_drop(dev->ifindex);
 582         return NOTIFY_DONE;
 583 }
 584
 585 static struct notifier_block ipq_dev_notifier = {
 586         .notifier_call  = ipq_rcv_dev_event,
 587 };
 588
 589 static int
 590 ipq_rcv_nl_event(struct notifier_block *this,
 591                  unsigned long event, void *ptr)
 592 {
 593         struct netlink_notify *n = ptr;
 594
 595         if (event == NETLINK_URELEASE &&
 596             n->protocol == NETLINK_FIREWALL && n->pid) {
 597                 write_lock_bh(&queue_lock);
 598                 if (n->pid == peer_pid)
 599                         __ipq_reset();
 600                 write_unlock_bh(&queue_lock);
 601         }
 602         return NOTIFY_DONE;
 603 }
 604
 605 static struct notifier_block ipq_nl_notifier = {
 606         .notifier_call  = ipq_rcv_nl_event,
 607 };
 608
 609 static struct ctl_table_header *ipq_sysctl_header;
 610
 611 static ctl_table ipq_table[] = {
 612         {
 613                 .ctl_name       = NET_IPQ_QMAX,
 614                 .procname       = NET_IPQ_QMAX_NAME,
 615                 .data           = &queue_maxlen,
 616                 .maxlen         = sizeof(queue_maxlen),
 617                 .mode           = 0644,
 618                 .proc_handler   = proc_dointvec
 619         },
 620         { .ctl_name = 0 }
 621 };
 622
 623 static ctl_table ipq_dir_table[] = {
 624         {
 625                 .ctl_name       = NET_IPV4,
 626                 .procname       = "ipv4",
 627                 .mode           = 0555,
 628                 .child          = ipq_table
 629         },
 630         { .ctl_name = 0 }
 631 };
 632
 633 static ctl_table ipq_root_table[] = {
 634         {
 635                 .ctl_name       = CTL_NET,
 636                 .procname       = "net",
 637                 .mode           = 0555,
 638                 .child          = ipq_dir_table
 639         },
 640         { .ctl_name = 0 }
 641 };
 642
 643 #ifdef CONFIG_PROC_FS
 644 static int
 645 ipq_get_info(char *buffer, char **start, off_t offset, int length)
 646 {
 647         int len;
 648
 649         read_lock_bh(&queue_lock);
 650
 651         len = sprintf(buffer,
 652                       "Peer PID          : %d\n"
 653                       "Copy mode         : %hu\n"
 654                       "Copy range        : %u\n"
 655                       "Queue length      : %u\n"
 656                       "Queue max. length : %u\n"
 657                       "Queue dropped     : %u\n"
 658                       "Netlink dropped   : %u\n",
 659                       peer_pid,
 660                       copy_mode,
 661                       copy_range,
 662                       queue_total,
 663                       queue_maxlen,
 664                       queue_dropped,
 665                       queue_user_dropped);
 666
 667         read_unlock_bh(&queue_lock);
 668
 669         *start = buffer + offset;
 670         len -= offset;
 671         if (len > length)
 672                 len = length;
 673         else if (len < 0)
 674                 len = 0;
 675         return len;
 676 }
 677 #endif /* CONFIG_PROC_FS */
 678
 679 static int
 680 init_or_cleanup(int init)
 681 {
 682         int status = -ENOMEM;
 683         struct proc_dir_entry *proc;
 684
 685         if (!init)
 686                 goto cleanup;
 687
 688         netlink_register_notifier(&ipq_nl_notifier);
 689         ipqnl = netlink_kernel_create(NETLINK_FIREWALL, ipq_rcv_sk);
 690         if (ipqnl == NULL) {
 691                 printk(KERN_ERR "ip_queue: failed to create netlink socket\n");
 692                 goto cleanup_netlink_notifier;
 693         }
 694
 695         proc = proc_net_create(IPQ_PROC_FS_NAME, 0, ipq_get_info);
 696         if (proc)
 697                 proc->owner = THIS_MODULE;
 698         else {
 699                 printk(KERN_ERR "ip_queue: failed to create proc entry\n");
 700                 goto cleanup_ipqnl;
 701         }
 702
 703         register_netdevice_notifier(&ipq_dev_notifier);
 704         ipq_sysctl_header = register_sysctl_table(ipq_root_table, 0);
 705
 706         status = nf_register_queue_handler(PF_INET, ipq_enqueue_packet, NULL);
 707         if (status < 0) {
 708                 printk(KERN_ERR "ip_queue: failed to register queue handler\n");
 709                 goto cleanup_sysctl;
 710         }
 711         return status;
 712
 713 cleanup:
 714         nf_unregister_queue_handler(PF_INET);
 715         synchronize_net();
 716         ipq_flush(NF_DROP);
 717
 718 cleanup_sysctl:
 719         unregister_sysctl_table(ipq_sysctl_header);
 720         unregister_netdevice_notifier(&ipq_dev_notifier);
 721         proc_net_remove(IPQ_PROC_FS_NAME);
 722
 723 cleanup_ipqnl:
 724         sock_release(ipqnl->sk_socket);
 725         down(&ipqnl_sem);
 726         up(&ipqnl_sem);
 727
 728 cleanup_netlink_notifier:
 729         netlink_unregister_notifier(&ipq_nl_notifier);
 730         return status;
 731 }
 732
 733 static int __init init(void)
 734 {
 735
 736         return init_or_cleanup(1);
 737 }
 738
 739 static void __exit fini(void)
 740 {
 741         init_or_cleanup(0);
 742 }
 743
 744 MODULE_DESCRIPTION("IPv4 packet queue handler");
 745 MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
 746 MODULE_LICENSE("GPL");
 747
 748 module_init(init);
 749 module_exit(fini);