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  * 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 (copy_range == 0 || copy_range > entry->skb->len)
 215                         data_len = entry->skb->len;
 216                 else
 217                         data_len = copy_range;
 218
 219                 size = NLMSG_SPACE(sizeof(*pmsg) + data_len);
 220                 break;
 221
 222         default:
 223                 *errp = -EINVAL;
 224                 read_unlock_bh(&queue_lock);
 225                 return NULL;
 226         }
 227
 228         read_unlock_bh(&queue_lock);
 229
 230         skb = alloc_skb(size, GFP_ATOMIC);
 231         if (!skb)
 232                 goto nlmsg_failure;
 233
 234         old_tail= skb->tail;
 235         nlh = NLMSG_PUT(skb, 0, 0, IPQM_PACKET, size - sizeof(*nlh));
 236         pmsg = NLMSG_DATA(nlh);
 237         memset(pmsg, 0, sizeof(*pmsg));
 238
 239         pmsg->packet_id       = (unsigned long )entry;
 240         pmsg->data_len        = data_len;
 241         pmsg->timestamp_sec   = entry->skb->stamp.tv_sec;
 242         pmsg->timestamp_usec  = entry->skb->stamp.tv_usec;
 243         pmsg->mark            = entry->skb->nfmark;
 244         pmsg->hook            = entry->info->hook;
 245         pmsg->hw_protocol     = entry->skb->protocol;
 246
 247         if (entry->info->indev)
 248                 strcpy(pmsg->indev_name, entry->info->indev->name);
 249         else
 250                 pmsg->indev_name[0] = '\0';
 251
 252         if (entry->info->outdev)
 253                 strcpy(pmsg->outdev_name, entry->info->outdev->name);
 254         else
 255                 pmsg->outdev_name[0] = '\0';
 256
 257         if (entry->info->indev && entry->skb->dev) {
 258                 pmsg->hw_type = entry->skb->dev->type;
 259                 if (entry->skb->dev->hard_header_parse)
 260                         pmsg->hw_addrlen =
 261                                 entry->skb->dev->hard_header_parse(entry->skb,
 262                                                                    pmsg->hw_addr);
 263         }
 264
 265         if (data_len)
 266                 if (skb_copy_bits(entry->skb, 0, pmsg->payload, data_len))
 267                         BUG();
 268
 269         nlh->nlmsg_len = skb->tail - old_tail;
 270         return skb;
 271
 272 nlmsg_failure:
 273         if (skb)
 274                 kfree_skb(skb);
 275         *errp = -EINVAL;
 276         printk(KERN_ERR "ip6_queue: error creating packet message\n");
 277         return NULL;
 278 }
 279
 280 static int
 281 ipq_enqueue_packet(struct sk_buff *skb, struct nf_info *info, void *data)
 282 {
 283         int status = -EINVAL;
 284         struct sk_buff *nskb;
 285         struct ipq_queue_entry *entry;
 286
 287         if (copy_mode == IPQ_COPY_NONE)
 288                 return -EAGAIN;
 289
 290         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 291         if (entry == NULL) {
 292                 printk(KERN_ERR "ip6_queue: OOM in ipq_enqueue_packet()\n");
 293                 return -ENOMEM;
 294         }
 295
 296         entry->info = info;
 297         entry->skb = skb;
 298
 299         if (entry->info->hook == NF_IP_LOCAL_OUT) {
 300                 struct ipv6hdr *iph = skb->nh.ipv6h;
 301
 302                 entry->rt_info.daddr = iph->daddr;
 303                 entry->rt_info.saddr = iph->saddr;
 304         }
 305
 306         nskb = ipq_build_packet_message(entry, &status);
 307         if (nskb == NULL)
 308                 goto err_out_free;
 309
 310         write_lock_bh(&queue_lock);
 311
 312         if (!peer_pid)
 313                 goto err_out_free_nskb;
 314
 315         if (queue_total >= queue_maxlen) {
 316                 queue_dropped++;
 317                 status = -ENOSPC;
 318                 if (net_ratelimit())
 319                         printk (KERN_WARNING "ip6_queue: fill at %d entries, "
 320                                 "dropping packet(s).  Dropped: %d\n", queue_total,
 321                                 queue_dropped);
 322                 goto err_out_free_nskb;
 323         }
 324
 325         /* netlink_unicast will either free the nskb or attach it to a socket */
 326         status = netlink_unicast(ipqnl, nskb, peer_pid, MSG_DONTWAIT);
 327         if (status < 0) {
 328                 queue_user_dropped++;
 329                 goto err_out_unlock;
 330         }
 331
 332         __ipq_enqueue_entry(entry);
 333
 334         write_unlock_bh(&queue_lock);
 335         return status;
 336
 337 err_out_free_nskb:
 338         kfree_skb(nskb);
 339
 340 err_out_unlock:
 341         write_unlock_bh(&queue_lock);
 342
 343 err_out_free:
 344         kfree(entry);
 345         return status;
 346 }
 347
 348 static int
 349 ipq_mangle_ipv6(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
 350 {
 351         int diff;
 352         struct ipv6hdr *user_iph = (struct ipv6hdr *)v->payload;
 353
 354         if (v->data_len < sizeof(*user_iph))
 355                 return 0;
 356         diff = v->data_len - e->skb->len;
 357         if (diff < 0)
 358                 skb_trim(e->skb, v->data_len);
 359         else if (diff > 0) {
 360                 if (v->data_len > 0xFFFF)
 361                         return -EINVAL;
 362                 if (diff > skb_tailroom(e->skb)) {
 363                         struct sk_buff *newskb;
 364
 365                         newskb = skb_copy_expand(e->skb,
 366                                                  skb_headroom(e->skb),
 367                                                  diff,
 368                                                  GFP_ATOMIC);
 369                         if (newskb == NULL) {
 370                                 printk(KERN_WARNING "ip6_queue: OOM "
 371                                       "in mangle, dropping packet\n");
 372                                 return -ENOMEM;
 373                         }
 374                         if (e->skb->sk)
 375                                 skb_set_owner_w(newskb, e->skb->sk);
 376                         kfree_skb(e->skb);
 377                         e->skb = newskb;
 378                 }
 379                 skb_put(e->skb, diff);
 380         }
 381         if (!skb_ip_make_writable(&e->skb, v->data_len))
 382                 return -ENOMEM;
 383         memcpy(e->skb->data, v->payload, v->data_len);
 384         e->skb->nfcache |= NFC_ALTERED;
 385
 386         /*
 387          * Extra routing may needed on local out, as the QUEUE target never
 388          * returns control to the table.
 389          * Not a nice way to cmp, but works
 390          */
 391         if (e->info->hook == NF_IP_LOCAL_OUT) {
 392                 struct ipv6hdr *iph = e->skb->nh.ipv6h;
 393                 if (!ipv6_addr_equal(&iph->daddr, &e->rt_info.daddr) ||
 394                     !ipv6_addr_equal(&iph->saddr, &e->rt_info.saddr))
 395                         return ip6_route_me_harder(e->skb);
 396         }
 397         return 0;
 398 }
 399
 400 static inline int
 401 id_cmp(struct ipq_queue_entry *e, unsigned long id)
 402 {
 403         return (id == (unsigned long )e);
 404 }
 405
 406 static int
 407 ipq_set_verdict(struct ipq_verdict_msg *vmsg, unsigned int len)
 408 {
 409         struct ipq_queue_entry *entry;
 410
 411         if (vmsg->value > NF_MAX_VERDICT)
 412                 return -EINVAL;
 413
 414         entry = ipq_find_dequeue_entry(id_cmp, vmsg->id);
 415         if (entry == NULL)
 416                 return -ENOENT;
 417         else {
 418                 int verdict = vmsg->value;
 419
 420                 if (vmsg->data_len && vmsg->data_len == len)
 421                         if (ipq_mangle_ipv6(vmsg, entry) < 0)
 422                                 verdict = NF_DROP;
 423
 424                 ipq_issue_verdict(entry, verdict);
 425                 return 0;
 426         }
 427 }
 428
 429 static int
 430 ipq_set_mode(unsigned char mode, unsigned int range)
 431 {
 432         int status;
 433
 434         write_lock_bh(&queue_lock);
 435         status = __ipq_set_mode(mode, range);
 436         write_unlock_bh(&queue_lock);
 437         return status;
 438 }
 439
 440 static int
 441 ipq_receive_peer(struct ipq_peer_msg *pmsg,
 442                  unsigned char type, unsigned int len)
 443 {
 444         int status = 0;
 445
 446         if (len < sizeof(*pmsg))
 447                 return -EINVAL;
 448
 449         switch (type) {
 450         case IPQM_MODE:
 451                 status = ipq_set_mode(pmsg->msg.mode.value,
 452                                       pmsg->msg.mode.range);
 453                 break;
 454
 455         case IPQM_VERDICT:
 456                 if (pmsg->msg.verdict.value > NF_MAX_VERDICT)
 457                         status = -EINVAL;
 458                 else
 459                         status = ipq_set_verdict(&pmsg->msg.verdict,
 460                                                  len - sizeof(*pmsg));
 461                         break;
 462         default:
 463                 status = -EINVAL;
 464         }
 465         return status;
 466 }
 467
 468 static int
 469 dev_cmp(struct ipq_queue_entry *entry, unsigned long ifindex)
 470 {
 471         if (entry->info->indev)
 472                 if (entry->info->indev->ifindex == ifindex)
 473                         return 1;
 474
 475         if (entry->info->outdev)
 476                 if (entry->info->outdev->ifindex == ifindex)
 477                         return 1;
 478
 479         return 0;
 480 }
 481
 482 static void
 483 ipq_dev_drop(int ifindex)
 484 {
 485         struct ipq_queue_entry *entry;
 486
 487         while ((entry = ipq_find_dequeue_entry(dev_cmp, ifindex)) != NULL)
 488                 ipq_issue_verdict(entry, NF_DROP);
 489 }
 490
 491 #define RCV_SKB_FAIL(err) do { netlink_ack(skb, nlh, (err)); return; } while (0)
 492
 493 static inline void
 494 ipq_rcv_skb(struct sk_buff *skb)
 495 {
 496         int status, type, pid, flags, nlmsglen, skblen;
 497         struct nlmsghdr *nlh;
 498
 499         skblen = skb->len;
 500         if (skblen < sizeof(*nlh))
 501                 return;
 502
 503         nlh = (struct nlmsghdr *)skb->data;
 504         nlmsglen = nlh->nlmsg_len;
 505         if (nlmsglen < sizeof(*nlh) || skblen < nlmsglen)
 506                 return;
 507
 508         pid = nlh->nlmsg_pid;
 509         flags = nlh->nlmsg_flags;
 510
 511         if(pid <= 0 || !(flags & NLM_F_REQUEST) || flags & NLM_F_MULTI)
 512                 RCV_SKB_FAIL(-EINVAL);
 513
 514         if (flags & MSG_TRUNC)
 515                 RCV_SKB_FAIL(-ECOMM);
 516
 517         type = nlh->nlmsg_type;
 518         if (type < NLMSG_NOOP || type >= IPQM_MAX)
 519                 RCV_SKB_FAIL(-EINVAL);
 520
 521         if (type <= IPQM_BASE)
 522                 return;
 523
 524         if (security_netlink_recv(skb))
 525                 RCV_SKB_FAIL(-EPERM);
 526
 527         write_lock_bh(&queue_lock);
 528
 529         if (peer_pid) {
 530                 if (peer_pid != pid) {
 531                         write_unlock_bh(&queue_lock);
 532                         RCV_SKB_FAIL(-EBUSY);
 533                 }
 534         } else {
 535                 net_enable_timestamp();
 536                 peer_pid = pid;
 537         }
 538
 539         write_unlock_bh(&queue_lock);
 540
 541         status = ipq_receive_peer(NLMSG_DATA(nlh), type,
 542                                   skblen - NLMSG_LENGTH(0));
 543         if (status < 0)
 544                 RCV_SKB_FAIL(status);
 545
 546         if (flags & NLM_F_ACK)
 547                 netlink_ack(skb, nlh, 0);
 548         return;
 549 }
 550
 551 static void
 552 ipq_rcv_sk(struct sock *sk, int len)
 553 {
 554         struct sk_buff *skb;
 555         unsigned int qlen;
 556
 557         down(&ipqnl_sem);
 558
 559         for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) {
 560                 skb = skb_dequeue(&sk->sk_receive_queue);
 561                 ipq_rcv_skb(skb);
 562                 kfree_skb(skb);
 563         }
 564
 565         up(&ipqnl_sem);
 566 }
 567
 568 static int
 569 ipq_rcv_dev_event(struct notifier_block *this,
 570                   unsigned long event, void *ptr)
 571 {
 572         struct net_device *dev = ptr;
 573
 574         /* Drop any packets associated with the downed device */
 575         if (event == NETDEV_DOWN)
 576                 ipq_dev_drop(dev->ifindex);
 577         return NOTIFY_DONE;
 578 }
 579
 580 static struct notifier_block ipq_dev_notifier = {
 581         .notifier_call  = ipq_rcv_dev_event,
 582 };
 583
 584 static int
 585 ipq_rcv_nl_event(struct notifier_block *this,
 586                  unsigned long event, void *ptr)
 587 {
 588         struct netlink_notify *n = ptr;
 589
 590         if (event == NETLINK_URELEASE &&
 591             n->protocol == NETLINK_IP6_FW && n->pid) {
 592                 write_lock_bh(&queue_lock);
 593                 if (n->pid == peer_pid)
 594                         __ipq_reset();
 595                 write_unlock_bh(&queue_lock);
 596         }
 597         return NOTIFY_DONE;
 598 }
 599
 600 static struct notifier_block ipq_nl_notifier = {
 601         .notifier_call  = ipq_rcv_nl_event,
 602 };
 603
 604 static struct ctl_table_header *ipq_sysctl_header;
 605
 606 static ctl_table ipq_table[] = {
 607         {
 608                 .ctl_name       = NET_IPQ_QMAX,
 609                 .procname       = NET_IPQ_QMAX_NAME,
 610                 .data           = &queue_maxlen,
 611                 .maxlen         = sizeof(queue_maxlen),
 612                 .mode           = 0644,
 613                 .proc_handler   = proc_dointvec
 614         },
 615         { .ctl_name = 0 }
 616 };
 617
 618 static ctl_table ipq_dir_table[] = {
 619         {
 620                 .ctl_name       = NET_IPV6,
 621                 .procname       = "ipv6",
 622                 .mode           = 0555,
 623                 .child          = ipq_table
 624         },
 625         { .ctl_name = 0 }
 626 };
 627
 628 static ctl_table ipq_root_table[] = {
 629         {
 630                 .ctl_name       = CTL_NET,
 631                 .procname       = "net",
 632                 .mode           = 0555,
 633                 .child          = ipq_dir_table
 634         },
 635         { .ctl_name = 0 }
 636 };
 637
 638 static int
 639 ipq_get_info(char *buffer, char **start, off_t offset, int length)
 640 {
 641         int len;
 642
 643         read_lock_bh(&queue_lock);
 644
 645         len = sprintf(buffer,
 646                       "Peer PID          : %d\n"
 647                       "Copy mode         : %hu\n"
 648                       "Copy range        : %u\n"
 649                       "Queue length      : %u\n"
 650                       "Queue max. length : %u\n"
 651                       "Queue dropped     : %u\n"
 652                       "Netfilter dropped : %u\n",
 653                       peer_pid,
 654                       copy_mode,
 655                       copy_range,
 656                       queue_total,
 657                       queue_maxlen,
 658                       queue_dropped,
 659                       queue_user_dropped);
 660
 661         read_unlock_bh(&queue_lock);
 662
 663         *start = buffer + offset;
 664         len -= offset;
 665         if (len > length)
 666                 len = length;
 667         else if (len < 0)
 668                 len = 0;
 669         return len;
 670 }
 671
 672 static int
 673 init_or_cleanup(int init)
 674 {
 675         int status = -ENOMEM;
 676         struct proc_dir_entry *proc;
 677
 678         if (!init)
 679                 goto cleanup;
 680
 681         netlink_register_notifier(&ipq_nl_notifier);
 682         ipqnl = netlink_kernel_create(NETLINK_IP6_FW, ipq_rcv_sk);
 683         if (ipqnl == NULL) {
 684                 printk(KERN_ERR "ip6_queue: failed to create netlink socket\n");
 685                 goto cleanup_netlink_notifier;
 686         }
 687
 688         proc = proc_net_create(IPQ_PROC_FS_NAME, 0, ipq_get_info);
 689         if (proc)
 690                 proc->owner = THIS_MODULE;
 691         else {
 692                 printk(KERN_ERR "ip6_queue: failed to create proc entry\n");
 693                 goto cleanup_ipqnl;
 694         }
 695
 696         register_netdevice_notifier(&ipq_dev_notifier);
 697         ipq_sysctl_header = register_sysctl_table(ipq_root_table, 0);
 698
 699         status = nf_register_queue_handler(PF_INET6, ipq_enqueue_packet, NULL);
 700         if (status < 0) {
 701                 printk(KERN_ERR "ip6_queue: failed to register queue handler\n");
 702                 goto cleanup_sysctl;
 703         }
 704         return status;
 705
 706 cleanup:
 707         nf_unregister_queue_handler(PF_INET6);
 708         synchronize_net();
 709         ipq_flush(NF_DROP);
 710
 711 cleanup_sysctl:
 712         unregister_sysctl_table(ipq_sysctl_header);
 713         unregister_netdevice_notifier(&ipq_dev_notifier);
 714         proc_net_remove(IPQ_PROC_FS_NAME);
 715
 716 cleanup_ipqnl:
 717         sock_release(ipqnl->sk_socket);
 718         down(&ipqnl_sem);
 719         up(&ipqnl_sem);
 720
 721 cleanup_netlink_notifier:
 722         netlink_unregister_notifier(&ipq_nl_notifier);
 723         return status;
 724 }
 725
 726 static int __init init(void)
 727 {
 728
 729         return init_or_cleanup(1);
 730 }
 731
 732 static void __exit fini(void)
 733 {
 734         init_or_cleanup(0);
 735 }
 736
 737 MODULE_DESCRIPTION("IPv6 packet queue handler");
 738 MODULE_LICENSE("GPL");
 739
 740 module_init(init);
 741 module_exit(fini);