net/ipv6/netfilter/ip6_queue.c

   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  * 2001-11-06: First try. Working with ip_queue.c for IPv4 and trying
  12  *             to adapt it to IPv6
  13  *             HEAVILY based in ipqueue.c by James Morris. It's just
  14  *             a little modified version of it, so he's nearly the
  15  *             real coder of this.
  16  *             Few changes needed, mainly the hard_routing code and
  17  *             the netlink socket protocol (we're NETLINK_IP6_FW).
  18  * 2002-06-25: Code cleanup. [JM: ported cleanup over from ip_queue.c]
  19  */
  20 #include <linux/module.h>
  21 #include <linux/skbuff.h>
  22 #include <linux/init.h>
  23 #include <linux/ipv6.h>
  24 #include <linux/notifier.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/netfilter.h>
  27 #include <linux/netlink.h>
  28 #include <linux/spinlock.h>
  29 #include <linux/brlock.h>
  30 #include <linux/sysctl.h>
  31 #include <linux/proc_fs.h>
  32 #include <net/sock.h>
  33 #include <net/ipv6.h>
  34 #include <net/ip6_route.h>
  35 #include <linux/netfilter_ipv4/ip_queue.h>
  36 #include <linux/netfilter_ipv4/ip_tables.h>
  37 #include <linux/netfilter_ipv6/ip6_tables.h>
  38
  39 #define IPQ_QMAX_DEFAULT 1024
  40 #define IPQ_PROC_FS_NAME "ip6_queue"
  41 #define NET_IPQ_QMAX 2088
  42 #define NET_IPQ_QMAX_NAME "ip6_queue_maxlen"
  43
  44 struct ipq_rt_info {
  45         struct in6_addr daddr;
  46         struct in6_addr saddr;
  47 };
  48
  49 struct ipq_queue_entry {
  50         struct list_head list;
  51         struct nf_info *info;
  52         struct sk_buff *skb;
  53         struct ipq_rt_info rt_info;
  54 };
  55
  56 typedef int (*ipq_cmpfn)(struct ipq_queue_entry *, unsigned long);
  57
  58 static unsigned char copy_mode = IPQ_COPY_NONE;
  59 static unsigned int queue_maxlen = IPQ_QMAX_DEFAULT;
  60 static rwlock_t queue_lock = RW_LOCK_UNLOCKED;
  61 static int peer_pid;
  62 static unsigned int copy_range;
  63 static unsigned int queue_total;
  64 static struct sock *ipqnl;
  65 static LIST_HEAD(queue_list);
  66 static DECLARE_MUTEX(ipqnl_sem);
  67
  68 static void
  69 ipq_issue_verdict(struct ipq_queue_entry *entry, int verdict)
  70 {
  71         nf_reinject(entry->skb, entry->info, verdict);
  72         kfree(entry);
  73 }
  74
  75 static inline int
  76 __ipq_enqueue_entry(struct ipq_queue_entry *entry)
  77 {
  78        if (queue_total >= queue_maxlen) {
  79                if (net_ratelimit())
  80                        printk(KERN_WARNING "ip6_queue: full at %d entries, "
  81                               "dropping packet(s).\n", queue_total);
  82                return -ENOSPC;
  83        }
  84        list_add(&entry->list, &queue_list);
  85        queue_total++;
  86        return 0;
  87 }
  88
  89 /*
  90  * Find and return a queued entry matched by cmpfn, or return the last
  91  * entry if cmpfn is NULL.
  92  */
  93 static inline struct ipq_queue_entry *
  94 __ipq_find_entry(ipq_cmpfn cmpfn, unsigned long data)
  95 {
  96         struct list_head *p;
  97
  98         list_for_each_prev(p, &queue_list) {
  99                 struct ipq_queue_entry *entry = (struct ipq_queue_entry *)p;
 100
 101                 if (!cmpfn || cmpfn(entry, data))
 102                         return entry;
 103         }
 104         return NULL;
 105 }
 106
 107 static inline void
 108 __ipq_dequeue_entry(struct ipq_queue_entry *entry)
 109 {
 110         list_del(&entry->list);
 111         queue_total--;
 112 }
 113
 114 static inline struct ipq_queue_entry *
 115 __ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 116 {
 117         struct ipq_queue_entry *entry;
 118
 119         entry = __ipq_find_entry(cmpfn, data);
 120         if (entry == NULL)
 121                 return NULL;
 122
 123         __ipq_dequeue_entry(entry);
 124         return entry;
 125 }
 126
 127
 128 static inline void
 129 __ipq_flush(int verdict)
 130 {
 131         struct ipq_queue_entry *entry;
 132
 133         while ((entry = __ipq_find_dequeue_entry(NULL, 0)))
 134                 ipq_issue_verdict(entry, verdict);
 135 }
 136
 137 static inline int
 138 __ipq_set_mode(unsigned char mode, unsigned int range)
 139 {
 140         int status = 0;
 141
 142         switch(mode) {
 143         case IPQ_COPY_NONE:
 144         case IPQ_COPY_META:
 145                 copy_mode = mode;
 146                 copy_range = 0;
 147                 break;
 148
 149         case IPQ_COPY_PACKET:
 150                 copy_mode = mode;
 151                 copy_range = range;
 152                 if (copy_range > 0xFFFF)
 153                         copy_range = 0xFFFF;
 154                 break;
 155
 156         default:
 157                 status = -EINVAL;
 158
 159         }
 160         return status;
 161 }
 162
 163 static inline void
 164 __ipq_reset(void)
 165 {
 166         peer_pid = 0;
 167         __ipq_set_mode(IPQ_COPY_NONE, 0);
 168         __ipq_flush(NF_DROP);
 169 }
 170
 171 static struct ipq_queue_entry *
 172 ipq_find_dequeue_entry(ipq_cmpfn cmpfn, unsigned long data)
 173 {
 174         struct ipq_queue_entry *entry;
 175
 176         write_lock_bh(&queue_lock);
 177         entry = __ipq_find_dequeue_entry(cmpfn, data);
 178         write_unlock_bh(&queue_lock);
 179         return entry;
 180 }
 181
 182 static void
 183 ipq_flush(int verdict)
 184 {
 185         write_lock_bh(&queue_lock);
 186         __ipq_flush(verdict);
 187         write_unlock_bh(&queue_lock);
 188 }
 189
 190 static struct sk_buff *
 191 ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
 192 {
 193         unsigned char *old_tail;
 194         size_t size = 0;
 195         size_t data_len = 0;
 196         struct sk_buff *skb;
 197         struct ipq_packet_msg *pmsg;
 198         struct nlmsghdr *nlh;
 199
 200         read_lock_bh(&queue_lock);
 201
 202         switch (copy_mode) {
 203         case IPQ_COPY_META:
 204         case IPQ_COPY_NONE:
 205                 size = NLMSG_SPACE(sizeof(*pmsg));
 206                 data_len = 0;
 207                 break;
 208
 209         case IPQ_COPY_PACKET:
 210                 if (copy_range == 0 || copy_range > entry->skb->len)
 211                         data_len = entry->skb->len;
 212                 else
 213                         data_len = copy_range;
 214
 215                 size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
 216                 break;
 217
 218         default:
 219                 *errp = -EINVAL;
 220                 read_unlock_bh(&queue_lock);
 221                 return NULL;
 222         }
 223
 224         read_unlock_bh(&queue_lock);
 225
 226         skb = alloc_skb(size, GFP_ATOMIC);
 227         if (!skb)
 228                 goto nlmsg_failure;
 229
 230         old_tail= skb->tail;
 231         nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
 232         pmsg = NLMSG_DATA(nlh);
 233         memset(pmsg, 0, sizeof(*pmsg));
 234
 235         pmsg->packet_id       = (unsigned long )entry;
 236         pmsg->data_len        = data_len;
 237         pmsg->timestamp_sec   = entry->skb->stamp.tv_sec;
 238         pmsg->timestamp_usec  = entry->skb->stamp.tv_usec;
 239         pmsg->mark            = entry->skb->nfmark;
 240         pmsg->hook            = entry->info->hook;
 241         pmsg->hw_protocol     = entry->skb->protocol;
 242
 243         if (entry->info->indev)
 244                 strcpy(pmsg->indev_name, entry->info->indev->name);
 245         else
 246                 pmsg->indev_name[0] = '\0';
 247
 248         if (entry->info->outdev)
 249                 strcpy(pmsg->outdev_name, entry->info->outdev->name);
 250         else
 251                 pmsg->outdev_name[0] = '\0';
 252
 253         if (entry->info->indev && entry->skb->dev) {
 254                 pmsg->hw_type = entry->skb->dev->type;
 255                 if (entry->skb->dev->hard_header_parse)
 256                         pmsg->hw_addrlen =
 257                                 entry->skb->dev->hard_header_parse(entry->skb,
 258                                                                    pmsg->hw_addr);
 259         }
 260
 261         if (data_len)
 262                 memcpy(pmsg->payload, entry->skb->data, data_len);
 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 "ip6_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 "ip6_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 ipv6hdr *iph = skb->nh.ipv6h;
 296
 297                 entry->rt_info.daddr = iph->daddr;
 298                 entry->rt_info.saddr = iph->saddr;
 299         }
 300
 301         nskb = ipq_build_packet_message(entry, &status);
 302         if (nskb == NULL)
 303                 goto err_out_free;
 304
 305         write_lock_bh(&queue_lock);
 306
 307         if (!peer_pid)
 308                 goto err_out_unlock;
 309
 310         status = netlink_unicast(ipqnl, nskb, peer_pid, MSG_DONTWAIT);
 311         if (status < 0)
 312                 goto err_out_unlock;
 313
 314         status = __ipq_enqueue_entry(entry);
 315         if (status < 0)
 316                 goto err_out_unlock;
 317
 318         write_unlock_bh(&queue_lock);
 319         return status;
 320
 321 err_out_unlock:
 322         write_unlock_bh(&queue_lock);
 323
 324 err_out_free:
 325         kfree(entry);
 326         return status;
 327 }
 328
 329 /*
 330  * Taken from net/ipv6/ip6_output.c
 331  *
 332  * We should use the one there, but is defined static
 333  * so we put this just here and let the things as
 334  * they are now.
 335  *
 336  * If that one is modified, this one should be modified too.
 337  */
 338 static int
 339 route6_me_harder(struct sk_buff *skb)
 340 {
 341         struct ipv6hdr *iph = skb->nh.ipv6h;
 342         struct dst_entry *dst;
 343         struct flowi fl;
 344
 345         fl.proto = iph->nexthdr;
 346         fl.fl6_dst = &iph->daddr;
 347         fl.fl6_src = &iph->saddr;
 348         fl.oif = skb->sk ? skb->sk->bound_dev_if : 0;
 349         fl.fl6_flowlabel = 0;
 350         fl.uli_u.ports.dport = 0;
 351         fl.uli_u.ports.sport = 0;
 352
 353         dst = ip6_route_output(skb->sk, &fl);
 354
 355         if (dst->error) {
 356                 if (net_ratelimit())
 357                         printk(KERN_DEBUG "route6_me_harder: No more route.\n");
 358                 return -EINVAL;
 359         }
 360
 361         /* Drop old route. */
 362         dst_release(skb->dst);
 363
 364         skb->dst = dst;
 365         return 0;
 366 }
 367
 368 static int
 369 ipq_mangle_ipv6(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
 370 {
 371         int diff;
 372         struct ipv6hdr *user_iph = (struct ipv6hdr *)v->payload;
 373
 374         if (v->data_len < sizeof(*user_iph))
 375                 return 0;
 376         diff = v->data_len - e->skb->len;
 377         if (diff < 0)
 378                 skb_trim(e->skb, v->data_len);
 379         else if (diff > 0) {
 380                 if (v->data_len > 0xFFFF)
 381                         return -EINVAL;
 382                 if (diff > skb_tailroom(e->skb)) {
 383                         struct sk_buff *newskb;
 384
 385                         newskb = skb_copy_expand(e->skb,
 386                                                  skb_headroom(e->skb),
 387                                                  diff,
 388                                                  GFP_ATOMIC);
 389                         if (newskb == NULL) {
 390                                 printk(KERN_WARNING "ip6_queue: OOM "
 391                                       "in mangle, dropping packet\n");
 392                                 return -ENOMEM;
 393                         }
 394                         if (e->skb->sk)
 395                                 skb_set_owner_w(newskb, e->skb->sk);
 396                         kfree_skb(e->skb);
 397                         e->skb = newskb;
 398                 }
 399                 skb_put(e->skb, diff);
 400         }
 401         memcpy(e->skb->data, v->payload, v->data_len);
 402         e->skb->nfcache |= NFC_ALTERED;
 403
 404         /*
 405          * Extra routing may needed on local out, as the QUEUE target never
 406          * returns control to the table.
 407          * Not a nice way to cmp, but works
 408          */
 409         if (e->info->hook == NF_IP_LOCAL_OUT) {
 410                 struct ipv6hdr *iph = e->skb->nh.ipv6h;
 411                 if (ipv6_addr_cmp(&iph->daddr, &e->rt_info.daddr) ||
 412                     ipv6_addr_cmp(&iph->saddr, &e->rt_info.saddr))
 413                         return route6_me_harder(e->skb);
 414         }
 415         return 0;
 416 }
 417
 418 static inline int
 419 id_cmp(struct ipq_queue_entry *e, unsigned long id)
 420 {
 421         return (id == (unsigned long )e);
 422 }
 423
 424 static int
 425 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
 426 {
 427         struct ipq_queue_entry *entry;
 428
 429         if (vmsg->value > NF_MAX_VERDICT)
 430                 return -EINVAL;
 431
 432         entry = ipq_find_dequeue_entry(id_cmp, vmsg->id);
 433         if (entry == NULL)
 434                 return -ENOENT;
 435         else {
 436                 int verdict = vmsg->value;
 437
 438                 if (vmsg->data_len && vmsg->data_len == len)
 439                         if (ipq_mangle_ipv6(vmsg, entry) < 0)
 440                                 verdict = NF_DROP;
 441
 442                 ipq_issue_verdict(entry, verdict);
 443                 return 0;
 444         }
 445 }
 446
 447 static int
 448 ipq_set_mode(unsigned char mode, unsigned int range)
 449 {
 450         int status;
 451
 452         write_lock_bh(&queue_lock);
 453         status = __ipq_set_mode(mode, range);
 454         write_unlock_bh(&queue_lock);
 455         return status;
 456 }
 457
 458 static int
 459 ipq_receive_peer(struct ipq_peer_msg *pmsg,
 460                  unsigned char type, unsigned int len)
 461 {
 462         int status = 0;
 463
 464         if (len < sizeof(*pmsg))
 465                 return -EINVAL;
 466
 467         switch (type) {
 468         case IPQM_MODE:
 469                 status = ipq_set_mode(pmsg->msg.mode.value,
 470                                       pmsg->msg.mode.range);
 471                 break;
 472
 473         case IPQM_VERDICT:
 474                 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
 475                         status = -EINVAL;
 476                 else
 477                         status = ipq_set_verdict(&pmsg->msg.verdict,
 478                                                  len - sizeof(*pmsg));
 479                         break;
 480         default:
 481                 status = -EINVAL;
 482         }
 483         return status;
 484 }
 485
 486 static int
 487 dev_cmp(struct ipq_queue_entry *entry, unsigned long ifindex)
 488 {
 489         if (entry->info->indev)
 490                 if (entry->info->indev->ifindex == ifindex)
 491                         return 1;
 492
 493         if (entry->info->outdev)
 494                 if (entry->info->outdev->ifindex == ifindex)
 495                         return 1;
 496
 497         return 0;
 498 }
 499
 500 static void
 501 ipq_dev_drop(int ifindex)
 502 {
 503         struct ipq_queue_entry *entry;
 504
 505         while ((entry = ipq_find_dequeue_entry(dev_cmp, ifindex)) != NULL)
 506                 ipq_issue_verdict(entry, NF_DROP);
 507 }
 508
 509 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 510
 511 static inline void
 512 ipq_rcv_skb(struct sk_buff *skb)
 513 {
 514         int status, type, pid, flags, nlmsglen, skblen;
 515         struct nlmsghdr *nlh;
 516
 517         skblen = skb->len;
 518         if (skblen < sizeof(*nlh))
 519                 return;
 520
 521         nlh = (struct nlmsghdr *)skb->data;
 522         nlmsglen = nlh->nlmsg_len;
 523         if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
 524                 return;
 525
 526         pid = nlh->nlmsg_pid;
 527         flags = nlh->nlmsg_flags;
 528
 529         if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
 530                 RCV_SKB_FAIL(-EINVAL);
 531
 532         if (flags & MSG_TRUNC)
 533                 RCV_SKB_FAIL(-ECOMM);
 534
 535         type = nlh->nlmsg_type;
 536         if (type < NLMSG_NOOP || type >= IPQM_MAX)
 537                 RCV_SKB_FAIL(-EINVAL);
 538
 539         if (type <= IPQM_BASE)
 540                 return;
 541
 542         if(!cap_raised(NETLINK_CB(skb).eff_cap, CAP_NET_ADMIN))
 543                 RCV_SKB_FAIL(-EPERM);
 544
 545         write_lock_bh(&queue_lock);
 546
 547         if (peer_pid) {
 548                 if (peer_pid != pid) {
 549                         write_unlock_bh(&queue_lock);
 550                         RCV_SKB_FAIL(-EBUSY);
 551                 }
 552         }
 553         else
 554                 peer_pid = pid;
 555
 556         write_unlock_bh(&queue_lock);
 557
 558         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 559                                   skblen - NLMSG_LENGTH(0));
 560         if (status < 0)
 561                 RCV_SKB_FAIL(status);
 562
 563         if (flags & NLM_F_ACK)
 564                 netlink_ack(skb, nlh, 0);
 565         return;
 566 }
 567
 568 static void
 569 ipq_rcv_sk(struct sock *sk, int len)
 570 {
 571         do {
 572                 struct sk_buff *skb;
 573
 574                 if (down_trylock(&ipqnl_sem))
 575                         return;
 576
 577                 while ((skb = skb_dequeue(&sk->receive_queue)) != NULL) {
 578                         ipq_rcv_skb(skb);
 579                         kfree_skb(skb);
 580                 }
 581
 582                 up(&ipqnl_sem);
 583
 584         } while (ipqnl && ipqnl->receive_queue.qlen);
 585 }
 586
 587 static int
 588 ipq_rcv_dev_event(struct notifier_block *this,
 589                   unsigned long event, void *ptr)
 590 {
 591         struct net_device *dev = ptr;
 592
 593         /* Drop any packets associated with the downed device */
 594         if (event == NETDEV_DOWN)
 595                 ipq_dev_drop(dev->ifindex);
 596         return NOTIFY_DONE;
 597 }
 598
 599 static struct notifier_block ipq_dev_notifier = {
 600         ipq_rcv_dev_event,
 601         NULL,
 602         0
 603 };
 604
 605 static int
 606 ipq_rcv_nl_event(struct notifier_block *this,
 607                  unsigned long event, void *ptr)
 608 {
 609         struct netlink_notify *n = ptr;
 610
 611         if (event == NETLINK_URELEASE &&
 612             n->protocol == NETLINK_IP6_FW && n->pid) {
 613                 write_lock_bh(&queue_lock);
 614                 if (n->pid == peer_pid)
 615                         __ipq_reset();
 616                 write_unlock_bh(&queue_lock);
 617         }
 618         return NOTIFY_DONE;
 619 }
 620
 621 static struct notifier_block ipq_nl_notifier = {
 622         ipq_rcv_nl_event,
 623         NULL,
 624         0
 625 };
 626
 627 static int sysctl_maxlen = IPQ_QMAX_DEFAULT;
 628 static struct ctl_table_header *ipq_sysctl_header;
 629
 630 static ctl_table ipq_table[] = {
 631         { NET_IPQ_QMAX, NET_IPQ_QMAX_NAME, &sysctl_maxlen,
 632           sizeof(sysctl_maxlen), 0644,  NULL, proc_dointvec },
 633         { 0 }
 634 };
 635
 636 static ctl_table ipq_dir_table[] = {
 637         {NET_IPV6, "ipv6", NULL, 0, 0555, ipq_table, 0, 0, 0, 0, 0},
 638         { 0 }
 639 };
 640
 641 static ctl_table ipq_root_table[] = {
 642         {CTL_NET, "net", NULL, 0, 0555, ipq_dir_table, 0, 0, 0, 0, 0},
 643         { 0 }
 644 };
 645
 646 static int
 647 ipq_get_info(char *buffer, char **start, off_t offset, int length)
 648 {
 649         int len;
 650
 651         read_lock_bh(&queue_lock);
 652
 653         len = sprintf(buffer,
 654                       "Peer PID          : %d\n"
 655                       "Copy mode         : %hu\n"
 656                       "Copy range        : %u\n"
 657                       "Queue length      : %u\n"
 658                       "Queue max. length : %u\n",
 659                       peer_pid,
 660                       copy_mode,
 661                       copy_range,
 662                       queue_total,
 663                       queue_maxlen);
 664
 665         read_unlock_bh(&queue_lock);
 666
 667         *start = buffer + offset;
 668         len -= offset;
 669         if (len > length)
 670                 len = length;
 671         else if (len < 0)
 672                 len = 0;
 673         return len;
 674 }
 675
 676 static int
 677 init_or_cleanup(int init)
 678 {
 679         int status = -ENOMEM;
 680         struct proc_dir_entry *proc;
 681
 682         if (!init)
 683                 goto cleanup;
 684
 685         netlink_register_notifier(&ipq_nl_notifier);
 686         ipqnl = netlink_kernel_create(NETLINK_IP6_FW, ipq_rcv_sk);
 687         if (ipqnl == NULL) {
 688                 printk(KERN_ERR "ip6_queue: failed to create netlink socket\n");
 689                 goto cleanup_netlink_notifier;
 690         }
 691
 692         proc = proc_net_create(IPQ_PROC_FS_NAME, 0, ipq_get_info);
 693         if (proc)
 694                 proc->owner = THIS_MODULE;
 695         else {
 696                 printk(KERN_ERR "ip6_queue: failed to create proc entry\n");
 697                 goto cleanup_ipqnl;
 698         }
 699
 700         register_netdevice_notifier(&ipq_dev_notifier);
 701         ipq_sysctl_header = register_sysctl_table(ipq_root_table, 0);
 702
 703         status = nf_register_queue_handler(PF_INET6, ipq_enqueue_packet, NULL);
 704         if (status < 0) {
 705                 printk(KERN_ERR "ip6_queue: failed to register queue handler\n");
 706                 goto cleanup_sysctl;
 707         }
 708         return status;
 709
 710 cleanup:
 711         nf_unregister_queue_handler(PF_INET6);
 712         br_write_lock_bh(BR_NETPROTO_LOCK);
 713         br_write_unlock_bh(BR_NETPROTO_LOCK);
 714         ipq_flush(NF_DROP);
 715
 716 cleanup_sysctl:
 717         unregister_sysctl_table(ipq_sysctl_header);
 718         unregister_netdevice_notifier(&ipq_dev_notifier);
 719         proc_net_remove(IPQ_PROC_FS_NAME);
 720
 721 cleanup_ipqnl:
 722         sock_release(ipqnl->socket);
 723         down(&ipqnl_sem);
 724         up(&ipqnl_sem);
 725
 726 cleanup_netlink_notifier:
 727         netlink_unregister_notifier(&ipq_nl_notifier);
 728         return status;
 729 }
 730
 731 static int __init init(void)
 732 {
 733
 734         return init_or_cleanup(1);
 735 }
 736
 737 static void __exit fini(void)
 738 {
 739         init_or_cleanup(0);
 740 }
 741
 742 MODULE_DESCRIPTION("IPv6 packet queue handler");
 743 MODULE_LICENSE("GPL");
 744
 745 module_init(init);
 746 module_exit(fini);