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   1 /*
   2  * This is a module which is used for queueing IPv6 packets and
   3  * communicating with userspace via netlink.
   4  *
   5  * (C) 2001 Fernando Anton, this code is GPL.
   6  *     IPv64 Project - Work based in IPv64 draft by Arturo Azcorra.
   7  *     Universidad Carlos III de Madrid - Leganes (Madrid) - Spain
   8  *     Universidad Politecnica de Alcala de Henares - Alcala de H. (Madrid) - Spain
   9  *     email: fanton@it.uc3m.es
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  *
  15  * 2001-11-06: First try. Working with ip_queue.c for IPv4 and trying
  16  *             to adapt it to IPv6
  17  *             HEAVILY based in ipqueue.c by James Morris. It's just
  18  *             a little modified version of it, so he's nearly the
  19  *             real coder of this.
  20  *             Few changes needed, mainly the hard_routing code and
  21  *             the netlink socket protocol (we're NETLINK_IP6_FW).
  22  * 2002-06-25: Code cleanup. [JM: ported cleanup over from ip_queue.c]
  23  * 2005-02-04: Added /proc counter for dropped packets; fixed so
  24  *             packets aren't delivered to user space if they're going
  25  *             to be dropped.
  26  */
  27 #include <linux/module.h>
  28 #include <linux/skbuff.h>
  29 #include <linux/init.h>
  30 #include <linux/ipv6.h>
  31 #include <linux/notifier.h>
  32 #include <linux/netdevice.h>
  33 #include <linux/netfilter.h>
  34 #include <linux/netlink.h>
  35 #include <linux/spinlock.h>
  36 #include <linux/sysctl.h>
  37 #include <linux/proc_fs.h>
  38 #include <net/sock.h>
  39 #include <net/ipv6.h>
  40 #include <net/ip6_route.h>
  41 #include <linux/netfilter_ipv4/ip_queue.h>
  42 #include <linux/netfilter_ipv4/ip_tables.h>
  43 #include <linux/netfilter_ipv6/ip6_tables.h>
  44
  45 #define IPQ_QMAX_DEFAULT 1024
  46 #define IPQ_PROC_FS_NAME "ip6_queue"
  47 #define NET_IPQ_QMAX 2088
  48 #define NET_IPQ_QMAX_NAME "ip6_queue_maxlen"
  49
  50 struct ipq_rt_info {
  51         struct in6_addr daddr;
  52         struct in6_addr saddr;
  53 };
  54
  55 struct ipq_queue_entry {
  56         struct list_head list;
  57         struct nf_info *info;
  58         struct sk_buff *skb;
  59         struct ipq_rt_info rt_info;
  60 };
  61
  62 typedef int (*ipq_cmpfn)(struct ipq_queue_entry *, unsigned long);
  63
  64 static unsigned char copy_mode = IPQ_COPY_NONE;
  65 static unsigned int queue_maxlen = IPQ_QMAX_DEFAULT;
  66 static DEFINE_RWLOCK(queue_lock);
  67 static int peer_pid;
  68 static unsigned int copy_range;
  69 static unsigned int queue_total;
  70 static unsigned int queue_dropped = 0;
  71 static unsigned int queue_user_dropped = 0;
  72 static struct sock *ipqnl;
  73 static LIST_HEAD(queue_list);
  74 static DECLARE_MUTEX(ipqnl_sem);
  75
  76 static void
  77 ipq_issue_verdict(struct ipq_queue_entry *entry, int verdict)
  78 {
  79         local_bh_disable();
  80         nf_reinject(entry->skb, entry->info, verdict);
  81         local_bh_enable();
  82         kfree(entry);
  83 }
  84
  85 static inline void
  86 __ipq_enqueue_entry(struct ipq_queue_entry *entry)
  87 {
  88        list_add(&entry->list, &queue_list);
  89        queue_total++;
  90 }
  91
  92 /*
  93  * Find and return a queued entry matched by cmpfn, or return the last
  94  * entry if cmpfn is NULL.
  95  */
  96 static inline struct ipq_queue_entry *
  97 __ipq_find_entry(ipq_cmpfn cmpfn, unsigned long data)
  98 {
  99         struct list_head *p;
 100
 101         list_for_each_prev(p, &queue_list) {
 102                 struct ipq_queue_entry *entry = (struct ipq_queue_entry *)p;
 103
 104                 if (!cmpfn || cmpfn(entry, data))
 105                         return entry;
 106         }
 107         return NULL;
 108 }
 109
 110 static inline void
 111 __ipq_dequeue_entry(struct ipq_queue_entry *entry)
 112 {
 113         list_del(&entry->list);
 114         queue_total--;
 115 }
 116
 117 static inline struct ipq_queue_entry *
 118 __ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 119 {
 120         struct ipq_queue_entry *entry;
 121
 122         entry = __ipq_find_entry(cmpfn, data);
 123         if (entry == NULL)
 124                 return NULL;
 125
 126         __ipq_dequeue_entry(entry);
 127         return entry;
 128 }
 129
 130
 131 static inline void
 132 __ipq_flush(int verdict)
 133 {
 134         struct ipq_queue_entry *entry;
 135
 136         while ((entry = __ipq_find_dequeue_entry(NULL, 0)))
 137                 ipq_issue_verdict(entry, verdict);
 138 }
 139
 140 static inline int
 141 __ipq_set_mode(unsigned char mode, unsigned int range)
 142 {
 143         int status = 0;
 144
 145         switch(mode) {
 146         case IPQ_COPY_NONE:
 147         case IPQ_COPY_META:
 148                 copy_mode = mode;
 149                 copy_range = 0;
 150                 break;
 151
 152         case IPQ_COPY_PACKET:
 153                 copy_mode = mode;
 154                 copy_range = range;
 155                 if (copy_range > 0xFFFF)
 156                         copy_range = 0xFFFF;
 157                 break;
 158
 159         default:
 160                 status = -EINVAL;
 161
 162         }
 163         return status;
 164 }
 165
 166 static inline void
 167 __ipq_reset(void)
 168 {
 169         peer_pid = 0;
 170         net_disable_timestamp();
 171         __ipq_set_mode(IPQ_COPY_NONE, 0);
 172         __ipq_flush(NF_DROP);
 173 }
 174
 175 static struct ipq_queue_entry *
 176 ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 177 {
 178         struct ipq_queue_entry *entry;
 179
 180         write_lock_bh(&queue_lock);
 181         entry = __ipq_find_dequeue_entry(cmpfn, data);
 182         write_unlock_bh(&queue_lock);
 183         return entry;
 184 }
 185
 186 static void
 187 ipq_flush(int verdict)
 188 {
 189         write_lock_bh(&queue_lock);
 190         __ipq_flush(verdict);
 191         write_unlock_bh(&queue_lock);
 192 }
 193
 194 static struct sk_buff *
 195 ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 196 {
 197         unsigned char *old_tail;
 198         size_t size = 0;
 199         size_t data_len = 0;
 200         struct sk_buff *skb;
 201         struct ipq_packet_msg *pmsg;
 202         struct nlmsghdr *nlh;
 203
 204         read_lock_bh(&queue_lock);
 205
 206         switch (copy_mode) {
 207         case IPQ_COPY_META:
 208         case IPQ_COPY_NONE:
 209                 size = NLMSG_SPACE(sizeof(*pmsg));
 210                 data_len = 0;
 211                 break;
 212
 213         case IPQ_COPY_PACKET:
 214                 if (entry->skb->ip_summed == CHECKSUM_HW &&
 215                     (*errp = skb_checksum_help(entry->skb,
 216                                                entry->info->outdev == NULL))) {
 217                         read_unlock_bh(&queue_lock);
 218                         return NULL;
 219                 }
 220                 if (copy_range == 0 || copy_range > entry->skb->len)
 221                         data_len = entry->skb->len;
 222                 else
 223                         data_len = copy_range;
 224
 225                 size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
 226                 break;
 227
 228         default:
 229                 *errp = -EINVAL;
 230                 read_unlock_bh(&queue_lock);
 231                 return NULL;
 232         }
 233
 234         read_unlock_bh(&queue_lock);
 235
 236         skb = alloc_skb(size, GFP_ATOMIC);
 237         if (!skb)
 238                 goto nlmsg_failure;
 239
 240         old_tail= skb->tail;
 241         nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
 242         pmsg = NLMSG_DATA(nlh);
 243         memset(pmsg, 0, sizeof(*pmsg));
 244
 245         pmsg->packet_id       = (unsigned long )entry;
 246         pmsg->data_len        = data_len;
 247         pmsg->timestamp_sec   = entry->skb->stamp.tv_sec;
 248         pmsg->timestamp_usec  = entry->skb->stamp.tv_usec;
 249         pmsg->mark            = entry->skb->nfmark;
 250         pmsg->hook            = entry->info->hook;
 251         pmsg->hw_protocol     = entry->skb->protocol;
 252
 253         if (entry->info->indev)
 254                 strcpy(pmsg->indev_name, entry->info->indev->name);
 255         else
 256                 pmsg->indev_name[0] = '\0';
 257
 258         if (entry->info->outdev)
 259                 strcpy(pmsg->outdev_name, entry->info->outdev->name);
 260         else
 261                 pmsg->outdev_name[0] = '\0';
 262
 263         if (entry->info->indev && entry->skb->dev) {
 264                 pmsg->hw_type = entry->skb->dev->type;
 265                 if (entry->skb->dev->hard_header_parse)
 266                         pmsg->hw_addrlen =
 267                                 entry->skb->dev->hard_header_parse(entry->skb,
 268                                                                    pmsg->hw_addr);
 269         }
 270
 271         if (data_len)
 272                 if (skb_copy_bits(entry->skb, 0, pmsg->payload, data_len))
 273                         BUG();
 274
 275         nlh->nlmsg_len = skb->tail - old_tail;
 276         return skb;
 277
 278 nlmsg_failure:
 279         if (skb)
 280                 kfree_skb(skb);
 281         *errp = -EINVAL;
 282         printk(KERN_ERR "ip6_queue: error creating packet message\n");
 283         return NULL;
 284 }
 285
 286 static int
 287 ipq_enqueue_packet(struct sk_buff *skb, struct nf_info *info, void *data)
 288 {
 289         int status = -EINVAL;
 290         struct sk_buff *nskb;
 291         struct ipq_queue_entry *entry;
 292
 293         if (copy_mode == IPQ_COPY_NONE)
 294                 return -EAGAIN;
 295
 296         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 297         if (entry == NULL) {
 298                 printk(KERN_ERR "ip6_queue: OOM in ipq_enqueue_packet()\n");
 299                 return -ENOMEM;
 300         }
 301
 302         entry->info = info;
 303         entry->skb = skb;
 304
 305         if (entry->info->hook == NF_IP_LOCAL_OUT) {
 306                 struct ipv6hdr *iph = skb->nh.ipv6h;
 307
 308                 entry->rt_info.daddr = iph->daddr;
 309                 entry->rt_info.saddr = iph->saddr;
 310         }
 311
 312         nskb = ipq_build_packet_message(entry, &status);
 313         if (nskb == NULL)
 314                 goto err_out_free;
 315
 316         write_lock_bh(&queue_lock);
 317
 318         if (!peer_pid)
 319                 goto err_out_free_nskb;
 320
 321         if (queue_total >= queue_maxlen) {
 322                 queue_dropped++;
 323                 status = -ENOSPC;
 324                 if (net_ratelimit())
 325                         printk (KERN_WARNING "ip6_queue: fill at %d entries, "
 326                                 "dropping packet(s).  Dropped: %d\n", queue_total,
 327                                 queue_dropped);
 328                 goto err_out_free_nskb;
 329         }
 330
 331         /* netlink_unicast will either free the nskb or attach it to a socket */
 332         status = netlink_unicast(ipqnl, nskb, peer_pid, MSG_DONTWAIT);
 333         if (status < 0) {
 334                 queue_user_dropped++;
 335                 goto err_out_unlock;
 336         }
 337
 338         __ipq_enqueue_entry(entry);
 339
 340         write_unlock_bh(&queue_lock);
 341         return status;
 342
 343 err_out_free_nskb:
 344         kfree_skb(nskb);
 345
 346 err_out_unlock:
 347         write_unlock_bh(&queue_lock);
 348
 349 err_out_free:
 350         kfree(entry);
 351         return status;
 352 }
 353
 354 static int
 355 ipq_mangle_ipv6(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
 356 {
 357         int diff;
 358         struct ipv6hdr *user_iph = (struct ipv6hdr *)v->payload;
 359
 360         if (v->data_len < sizeof(*user_iph))
 361                 return 0;
 362         diff = v->data_len - e->skb->len;
 363         if (diff < 0)
 364                 skb_trim(e->skb, v->data_len);
 365         else if (diff > 0) {
 366                 if (v->data_len > 0xFFFF)
 367                         return -EINVAL;
 368                 if (diff > skb_tailroom(e->skb)) {
 369                         struct sk_buff *newskb;
 370
 371                         newskb = skb_copy_expand(e->skb,
 372                                                  skb_headroom(e->skb),
 373                                                  diff,
 374                                                  GFP_ATOMIC);
 375                         if (newskb == NULL) {
 376                                 printk(KERN_WARNING "ip6_queue: OOM "
 377                                       "in mangle, dropping packet\n");
 378                                 return -ENOMEM;
 379                         }
 380                         if (e->skb->sk)
 381                                 skb_set_owner_w(newskb, e->skb->sk);
 382                         kfree_skb(e->skb);
 383                         e->skb = newskb;
 384                 }
 385                 skb_put(e->skb, diff);
 386         }
 387         if (!skb_make_writable(&e->skb, v->data_len))
 388                 return -ENOMEM;
 389         memcpy(e->skb->data, v->payload, v->data_len);
 390         e->skb->ip_summed = CHECKSUM_NONE;
 391
 392         /*
 393          * Extra routing may needed on local out, as the QUEUE target never
 394          * returns control to the table.
 395          * Not a nice way to cmp, but works
 396          */
 397         if (e->info->hook == NF_IP_LOCAL_OUT) {
 398                 struct ipv6hdr *iph = e->skb->nh.ipv6h;
 399                 if (!ipv6_addr_equal(&iph->daddr, &e->rt_info.daddr) ||
 400                     !ipv6_addr_equal(&iph->saddr, &e->rt_info.saddr))
 401                         return ip6_route_me_harder(e->skb);
 402         }
 403         return 0;
 404 }
 405
 406 static inline int
 407 id_cmp(struct ipq_queue_entry *e, unsigned long id)
 408 {
 409         return (id == (unsigned long )e);
 410 }
 411
 412 static int
 413 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
 414 {
 415         struct ipq_queue_entry *entry;
 416
 417         if (vmsg->value > NF_MAX_VERDICT)
 418                 return -EINVAL;
 419
 420         entry = ipq_find_dequeue_entry(id_cmp, vmsg->id);
 421         if (entry == NULL)
 422                 return -ENOENT;
 423         else {
 424                 int verdict = vmsg->value;
 425
 426                 if (vmsg->data_len && vmsg->data_len == len)
 427                         if (ipq_mangle_ipv6(vmsg, entry) < 0)
 428                                 verdict = NF_DROP;
 429
 430                 ipq_issue_verdict(entry, verdict);
 431                 return 0;
 432         }
 433 }
 434
 435 static int
 436 ipq_set_mode(unsigned char mode, unsigned int range)
 437 {
 438         int status;
 439
 440         write_lock_bh(&queue_lock);
 441         status = __ipq_set_mode(mode, range);
 442         write_unlock_bh(&queue_lock);
 443         return status;
 444 }
 445
 446 static int
 447 ipq_receive_peer(struct ipq_peer_msg *pmsg,
 448                  unsigned char type, unsigned int len)
 449 {
 450         int status = 0;
 451
 452         if (len < sizeof(*pmsg))
 453                 return -EINVAL;
 454
 455         switch (type) {
 456         case IPQM_MODE:
 457                 status = ipq_set_mode(pmsg->msg.mode.value,
 458                                       pmsg->msg.mode.range);
 459                 break;
 460
 461         case IPQM_VERDICT:
 462                 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
 463                         status = -EINVAL;
 464                 else
 465                         status = ipq_set_verdict(&pmsg->msg.verdict,
 466                                                  len - sizeof(*pmsg));
 467                         break;
 468         default:
 469                 status = -EINVAL;
 470         }
 471         return status;
 472 }
 473
 474 static int
 475 dev_cmp(struct ipq_queue_entry *entry, unsigned long ifindex)
 476 {
 477         if (entry->info->indev)
 478                 if (entry->info->indev->ifindex == ifindex)
 479                         return 1;
 480
 481         if (entry->info->outdev)
 482                 if (entry->info->outdev->ifindex == ifindex)
 483                         return 1;
 484
 485         return 0;
 486 }
 487
 488 static void
 489 ipq_dev_drop(int ifindex)
 490 {
 491         struct ipq_queue_entry *entry;
 492
 493         while ((entry = ipq_find_dequeue_entry(dev_cmp, ifindex)) != NULL)
 494                 ipq_issue_verdict(entry, NF_DROP);
 495 }
 496
 497 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 498
 499 static inline void
 500 ipq_rcv_skb(struct sk_buff *skb)
 501 {
 502         int status, type, pid, flags, nlmsglen, skblen;
 503         struct nlmsghdr *nlh;
 504
 505         skblen = skb->len;
 506         if (skblen < sizeof(*nlh))
 507                 return;
 508
 509         nlh = (struct nlmsghdr *)skb->data;
 510         nlmsglen = nlh->nlmsg_len;
 511         if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
 512                 return;
 513
 514         pid = nlh->nlmsg_pid;
 515         flags = nlh->nlmsg_flags;
 516
 517         if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
 518                 RCV_SKB_FAIL(-EINVAL);
 519
 520         if (flags & MSG_TRUNC)
 521                 RCV_SKB_FAIL(-ECOMM);
 522
 523         type = nlh->nlmsg_type;
 524         if (type < NLMSG_NOOP || type >= IPQM_MAX)
 525                 RCV_SKB_FAIL(-EINVAL);
 526
 527         if (type <= IPQM_BASE)
 528                 return;
 529
 530         if (security_netlink_recv(skb))
 531                 RCV_SKB_FAIL(-EPERM);
 532
 533         write_lock_bh(&queue_lock);
 534
 535         if (peer_pid) {
 536                 if (peer_pid != pid) {
 537                         write_unlock_bh(&queue_lock);
 538                         RCV_SKB_FAIL(-EBUSY);
 539                 }
 540         } else {
 541                 net_enable_timestamp();
 542                 peer_pid = pid;
 543         }
 544
 545         write_unlock_bh(&queue_lock);
 546
 547         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 548                                   skblen - NLMSG_LENGTH(0));
 549         if (status < 0)
 550                 RCV_SKB_FAIL(status);
 551
 552         if (flags & NLM_F_ACK)
 553                 netlink_ack(skb, nlh, 0);
 554         return;
 555 }
 556
 557 static void
 558 ipq_rcv_sk(struct sock *sk, int len)
 559 {
 560         struct sk_buff *skb;
 561         unsigned int qlen;
 562
 563         down(&ipqnl_sem);
 564
 565         for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
 566                 skb = skb_dequeue(&sk->sk_receive_queue);
 567                 ipq_rcv_skb(skb);
 568                 kfree_skb(skb);
 569         }
 570
 571         up(&ipqnl_sem);
 572 }
 573
 574 static int
 575 ipq_rcv_dev_event(struct notifier_block *this,
 576                   unsigned long event, void *ptr)
 577 {
 578         struct net_device *dev = ptr;
 579
 580         /* Drop any packets associated with the downed device */
 581         if (event == NETDEV_DOWN)
 582                 ipq_dev_drop(dev->ifindex);
 583         return NOTIFY_DONE;
 584 }
 585
 586 static struct notifier_block ipq_dev_notifier = {
 587         .notifier_call  = ipq_rcv_dev_event,
 588 };
 589
 590 static int
 591 ipq_rcv_nl_event(struct notifier_block *this,
 592                  unsigned long event, void *ptr)
 593 {
 594         struct netlink_notify *n = ptr;
 595
 596         if (event == NETLINK_URELEASE &&
 597             n->protocol == NETLINK_IP6_FW && n->pid) {
 598                 write_lock_bh(&queue_lock);
 599                 if (n->pid == peer_pid)
 600                         __ipq_reset();
 601                 write_unlock_bh(&queue_lock);
 602         }
 603         return NOTIFY_DONE;
 604 }
 605
 606 static struct notifier_block ipq_nl_notifier = {
 607         .notifier_call  = ipq_rcv_nl_event,
 608 };
 609
 610 static struct ctl_table_header *ipq_sysctl_header;
 611
 612 static ctl_table ipq_table[] = {
 613         {
 614                 .ctl_name       = NET_IPQ_QMAX,
 615                 .procname       = NET_IPQ_QMAX_NAME,
 616                 .data           = &queue_maxlen,
 617                 .maxlen         = sizeof(queue_maxlen),
 618                 .mode           = 0644,
 619                 .proc_handler   = proc_dointvec
 620         },
 621         { .ctl_name = 0 }
 622 };
 623
 624 static ctl_table ipq_dir_table[] = {
 625         {
 626                 .ctl_name       = NET_IPV6,
 627                 .procname       = "ipv6",
 628                 .mode           = 0555,
 629                 .child          = ipq_table
 630         },
 631         { .ctl_name = 0 }
 632 };
 633
 634 static ctl_table ipq_root_table[] = {
 635         {
 636                 .ctl_name       = CTL_NET,
 637                 .procname       = "net",
 638                 .mode           = 0555,
 639                 .child          = ipq_dir_table
 640         },
 641         { .ctl_name = 0 }
 642 };
 643
 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                       "Netfilter 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
 678 static int
 679 init_or_cleanup(int init)
 680 {
 681         int status = -ENOMEM;
 682         struct proc_dir_entry *proc;
 683
 684         if (!init)
 685                 goto cleanup;
 686
 687         netlink_register_notifier(&ipq_nl_notifier);
 688         ipqnl = netlink_kernel_create(NETLINK_IP6_FW, ipq_rcv_sk, THIS_MODULE);
 689         if (ipqnl == NULL) {
 690                 printk(KERN_ERR "ip6_queue: failed to create netlink socket\n");
 691                 goto cleanup_netlink_notifier;
 692         }
 693
 694         proc = proc_net_create(IPQ_PROC_FS_NAME, 0, ipq_get_info);
 695         if (proc)
 696                 proc->owner = THIS_MODULE;
 697         else {
 698                 printk(KERN_ERR "ip6_queue: failed to create proc entry\n");
 699                 goto cleanup_ipqnl;
 700         }
 701
 702         register_netdevice_notifier(&ipq_dev_notifier);
 703         ipq_sysctl_header = register_sysctl_table(ipq_root_table, 0);
 704
 705         status = nf_register_queue_handler(PF_INET6, ipq_enqueue_packet, NULL);
 706         if (status < 0) {
 707                 printk(KERN_ERR "ip6_queue: failed to register queue handler\n");
 708                 goto cleanup_sysctl;
 709         }
 710         return status;
 711
 712 cleanup:
 713         nf_unregister_queue_handler(PF_INET6);
 714         synchronize_net();
 715         ipq_flush(NF_DROP);
 716
 717 cleanup_sysctl:
 718         unregister_sysctl_table(ipq_sysctl_header);
 719         unregister_netdevice_notifier(&ipq_dev_notifier);
 720         proc_net_remove(IPQ_PROC_FS_NAME);
 721
 722 cleanup_ipqnl:
 723         sock_release(ipqnl->sk_socket);
 724         down(&ipqnl_sem);
 725         up(&ipqnl_sem);
 726
 727 cleanup_netlink_notifier:
 728         netlink_unregister_notifier(&ipq_nl_notifier);
 729         return status;
 730 }
 731
 732 static int __init init(void)
 733 {
 734
 735         return init_or_cleanup(1);
 736 }
 737
 738 static void __exit fini(void)
 739 {
 740         init_or_cleanup(0);
 741 }
 742
 743 MODULE_DESCRIPTION("IPv6 packet queue handler");
 744 MODULE_LICENSE("GPL");
 745
 746 module_init(init);
 747 module_exit(fini);