net/ipv6/netfilter/nf_conntrack_reasm.c

   1 /*
   2  * IPv6 fragment reassembly for connection tracking
   3  *
   4  * Copyright (C)2004 USAGI/WIDE Project
   5  *
   6  * Author:
   7  *      Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
   8  *
   9  * Based on: net/ipv6/reassembly.c
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version
  14  * 2 of the License, or (at your option) any later version.
  15  */
  16
  17 #define pr_fmt(fmt) "IPv6-nf: " fmt
  18
  19 #include <linux/errno.h>
  20 #include <linux/types.h>
  21 #include <linux/string.h>
  22 #include <linux/socket.h>
  23 #include <linux/sockios.h>
  24 #include <linux/jiffies.h>
  25 #include <linux/net.h>
  26 #include <linux/list.h>
  27 #include <linux/netdevice.h>
  28 #include <linux/in6.h>
  29 #include <linux/ipv6.h>
  30 #include <linux/icmpv6.h>
  31 #include <linux/random.h>
  32 #include <linux/slab.h>
  33
  34 #include <net/sock.h>
  35 #include <net/snmp.h>
  36 #include <net/ipv6_frag.h>
  37
  38 #include <net/protocol.h>
  39 #include <net/transp_v6.h>
  40 #include <net/rawv6.h>
  41 #include <net/ndisc.h>
  42 #include <net/addrconf.h>
  43 #include <net/inet_ecn.h>
  44 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
  45 #include <linux/sysctl.h>
  46 #include <linux/netfilter.h>
  47 #include <linux/netfilter_ipv6.h>
  48 #include <linux/kernel.h>
  49 #include <linux/module.h>
  50 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
  51
  52 static const char nf_frags_cache_name[] = "nf-frags";
  53
  54 static struct inet_frags nf_frags;
  55
  56 #ifdef CONFIG_SYSCTL
  57
  58 static struct ctl_table nf_ct_frag6_sysctl_table[] = {
  59         {
  60                 .procname       = "nf_conntrack_frag6_timeout",
  61                 .data           = &init_net.nf_frag.frags.timeout,
  62                 .maxlen         = sizeof(unsigned int),
  63                 .mode           = 0644,
  64                 .proc_handler   = proc_dointvec_jiffies,
  65         },
  66         {
  67                 .procname       = "nf_conntrack_frag6_low_thresh",
  68                 .data           = &init_net.nf_frag.frags.low_thresh,
  69                 .maxlen         = sizeof(unsigned long),
  70                 .mode           = 0644,
  71                 .proc_handler   = proc_doulongvec_minmax,
  72                 .extra2         = &init_net.nf_frag.frags.high_thresh
  73         },
  74         {
  75                 .procname       = "nf_conntrack_frag6_high_thresh",
  76                 .data           = &init_net.nf_frag.frags.high_thresh,
  77                 .maxlen         = sizeof(unsigned long),
  78                 .mode           = 0644,
  79                 .proc_handler   = proc_doulongvec_minmax,
  80                 .extra1         = &init_net.nf_frag.frags.low_thresh
  81         },
  82         { }
  83 };
  84
  85 static int nf_ct_frag6_sysctl_register(struct net *net)
  86 {
  87         struct ctl_table *table;
  88         struct ctl_table_header *hdr;
  89
  90         table = nf_ct_frag6_sysctl_table;
  91         if (!net_eq(net, &init_net)) {
  92                 table = kmemdup(table, sizeof(nf_ct_frag6_sysctl_table),
  93                                 GFP_KERNEL);
  94                 if (table == NULL)
  95                         goto err_alloc;
  96
  97                 table[0].data = &net->nf_frag.frags.timeout;
  98                 table[1].data = &net->nf_frag.frags.low_thresh;
  99                 table[1].extra2 = &net->nf_frag.frags.high_thresh;
 100                 table[2].data = &net->nf_frag.frags.high_thresh;
 101                 table[2].extra1 = &net->nf_frag.frags.low_thresh;
 102                 table[2].extra2 = &init_net.nf_frag.frags.high_thresh;
 103         }
 104
 105         hdr = register_net_sysctl(net, "net/netfilter", table);
 106         if (hdr == NULL)
 107                 goto err_reg;
 108
 109         net->nf_frag_frags_hdr = hdr;
 110         return 0;
 111
 112 err_reg:
 113         if (!net_eq(net, &init_net))
 114                 kfree(table);
 115 err_alloc:
 116         return -ENOMEM;
 117 }
 118
 119 static void __net_exit nf_ct_frags6_sysctl_unregister(struct net *net)
 120 {
 121         struct ctl_table *table;
 122
 123         table = net->nf_frag_frags_hdr->ctl_table_arg;
 124         unregister_net_sysctl_table(net->nf_frag_frags_hdr);
 125         if (!net_eq(net, &init_net))
 126                 kfree(table);
 127 }
 128
 129 #else
 130 static int nf_ct_frag6_sysctl_register(struct net *net)
 131 {
 132         return 0;
 133 }
 134 static void __net_exit nf_ct_frags6_sysctl_unregister(struct net *net)
 135 {
 136 }
 137 #endif
 138
 139 static inline u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h)
 140 {
 141         return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK);
 142 }
 143
 144 static void nf_ct_frag6_expire(struct timer_list *t)
 145 {
 146         struct inet_frag_queue *frag = from_timer(frag, t, timer);
 147         struct frag_queue *fq;
 148         struct net *net;
 149
 150         fq = container_of(frag, struct frag_queue, q);
 151         net = container_of(fq->q.net, struct net, nf_frag.frags);
 152
 153         ip6frag_expire_frag_queue(net, fq);
 154 }
 155
 156 /* Creation primitives. */
 157 static struct frag_queue *fq_find(struct net *net, __be32 id, u32 user,
 158                                   const struct ipv6hdr *hdr, int iif)
 159 {
 160         struct frag_v6_compare_key key = {
 161                 .id = id,
 162                 .saddr = hdr->saddr,
 163                 .daddr = hdr->daddr,
 164                 .user = user,
 165                 .iif = iif,
 166         };
 167         struct inet_frag_queue *q;
 168
 169         q = inet_frag_find(&net->nf_frag.frags, &key);
 170         if (!q)
 171                 return NULL;
 172
 173         return container_of(q, struct frag_queue, q);
 174 }
 175
 176
 177 static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb,
 178                              const struct frag_hdr *fhdr, int nhoff)
 179 {
 180         struct sk_buff *prev, *next;
 181         unsigned int payload_len;
 182         int offset, end;
 183         u8 ecn;
 184
 185         if (fq->q.flags & INET_FRAG_COMPLETE) {
 186                 pr_debug("Already completed\n");
 187                 goto err;
 188         }
 189
 190         payload_len = ntohs(ipv6_hdr(skb)->payload_len);
 191
 192         offset = ntohs(fhdr->frag_off) & ~0x7;
 193         end = offset + (payload_len -
 194                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
 195
 196         if ((unsigned int)end > IPV6_MAXPLEN) {
 197                 pr_debug("offset is too large.\n");
 198                 return -EINVAL;
 199         }
 200
 201         ecn = ip6_frag_ecn(ipv6_hdr(skb));
 202
 203         if (skb->ip_summed == CHECKSUM_COMPLETE) {
 204                 const unsigned char *nh = skb_network_header(skb);
 205                 skb->csum = csum_sub(skb->csum,
 206                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
 207                                                   0));
 208         }
 209
 210         /* Is this the final fragment? */
 211         if (!(fhdr->frag_off & htons(IP6_MF))) {
 212                 /* If we already have some bits beyond end
 213                  * or have different end, the segment is corrupted.
 214                  */
 215                 if (end < fq->q.len ||
 216                     ((fq->q.flags & INET_FRAG_LAST_IN) && end != fq->q.len)) {
 217                         pr_debug("already received last fragment\n");
 218                         goto err;
 219                 }
 220                 fq->q.flags |= INET_FRAG_LAST_IN;
 221                 fq->q.len = end;
 222         } else {
 223                 /* Check if the fragment is rounded to 8 bytes.
 224                  * Required by the RFC.
 225                  */
 226                 if (end & 0x7) {
 227                         /* RFC2460 says always send parameter problem in
 228                          * this case. -DaveM
 229                          */
 230                         pr_debug("end of fragment not rounded to 8 bytes.\n");
 231                         inet_frag_kill(&fq->q);
 232                         return -EPROTO;
 233                 }
 234                 if (end > fq->q.len) {
 235                         /* Some bits beyond end -> corruption. */
 236                         if (fq->q.flags & INET_FRAG_LAST_IN) {
 237                                 pr_debug("last packet already reached.\n");
 238                                 goto err;
 239                         }
 240                         fq->q.len = end;
 241                 }
 242         }
 243
 244         if (end == offset)
 245                 goto err;
 246
 247         /* Point into the IP datagram 'data' part. */
 248         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) {
 249                 pr_debug("queue: message is too short.\n");
 250                 goto err;
 251         }
 252         if (pskb_trim_rcsum(skb, end - offset)) {
 253                 pr_debug("Can't trim\n");
 254                 goto err;
 255         }
 256
 257         /* Find out which fragments are in front and at the back of us
 258          * in the chain of fragments so far.  We must know where to put
 259          * this fragment, right?
 260          */
 261         prev = fq->q.fragments_tail;
 262         if (!prev || prev->ip_defrag_offset < offset) {
 263                 next = NULL;
 264                 goto found;
 265         }
 266         prev = NULL;
 267         for (next = fq->q.fragments; next != NULL; next = next->next) {
 268                 if (next->ip_defrag_offset >= offset)
 269                         break;  /* bingo! */
 270                 prev = next;
 271         }
 272
 273 found:
 274         /* RFC5722, Section 4:
 275          *                                  When reassembling an IPv6 datagram, if
 276          *   one or more its constituent fragments is determined to be an
 277          *   overlapping fragment, the entire datagram (and any constituent
 278          *   fragments, including those not yet received) MUST be silently
 279          *   discarded.
 280          */
 281
 282         /* Check for overlap with preceding fragment. */
 283         if (prev &&
 284             (prev->ip_defrag_offset + prev->len) > offset)
 285                 goto discard_fq;
 286
 287         /* Look for overlap with succeeding segment. */
 288         if (next && next->ip_defrag_offset < end)
 289                 goto discard_fq;
 290
 291         /* Note : skb->ip_defrag_offset and skb->dev share the same location */
 292         if (skb->dev)
 293                 fq->iif = skb->dev->ifindex;
 294         /* Makes sure compiler wont do silly aliasing games */
 295         barrier();
 296         skb->ip_defrag_offset = offset;
 297
 298         /* Insert this fragment in the chain of fragments. */
 299         skb->next = next;
 300         if (!next)
 301                 fq->q.fragments_tail = skb;
 302         if (prev)
 303                 prev->next = skb;
 304         else
 305                 fq->q.fragments = skb;
 306
 307         fq->q.stamp = skb->tstamp;
 308         fq->q.meat += skb->len;
 309         fq->ecn |= ecn;
 310         if (payload_len > fq->q.max_size)
 311                 fq->q.max_size = payload_len;
 312         add_frag_mem_limit(fq->q.net, skb->truesize);
 313
 314         /* The first fragment.
 315          * nhoffset is obtained from the first fragment, of course.
 316          */
 317         if (offset == 0) {
 318                 fq->nhoffset = nhoff;
 319                 fq->q.flags |= INET_FRAG_FIRST_IN;
 320         }
 321
 322         return 0;
 323
 324 discard_fq:
 325         inet_frag_kill(&fq->q);
 326 err:
 327         return -EINVAL;
 328 }
 329
 330 /*
 331  *      Check if this packet is complete.
 332  *
 333  *      It is called with locked fq, and caller must check that
 334  *      queue is eligible for reassembly i.e. it is not COMPLETE,
 335  *      the last and the first frames arrived and all the bits are here.
 336  *
 337  *      returns true if *prev skb has been transformed into the reassembled
 338  *      skb, false otherwise.
 339  */
 340 static bool
 341 nf_ct_frag6_reasm(struct frag_queue *fq, struct sk_buff *prev,  struct net_device *dev)
 342 {
 343         struct sk_buff *fp, *head = fq->q.fragments;
 344         int    payload_len;
 345         u8 ecn;
 346
 347         inet_frag_kill(&fq->q);
 348
 349         WARN_ON(head == NULL);
 350         WARN_ON(head->ip_defrag_offset != 0);
 351
 352         ecn = ip_frag_ecn_table[fq->ecn];
 353         if (unlikely(ecn == 0xff))
 354                 return false;
 355
 356         /* Unfragmented part is taken from the first segment. */
 357         payload_len = ((head->data - skb_network_header(head)) -
 358                        sizeof(struct ipv6hdr) + fq->q.len -
 359                        sizeof(struct frag_hdr));
 360         if (payload_len > IPV6_MAXPLEN) {
 361                 net_dbg_ratelimited("nf_ct_frag6_reasm: payload len = %d\n",
 362                                     payload_len);
 363                 return false;
 364         }
 365
 366         /* Head of list must not be cloned. */
 367         if (skb_unclone(head, GFP_ATOMIC))
 368                 return false;
 369
 370         /* If the first fragment is fragmented itself, we split
 371          * it to two chunks: the first with data and paged part
 372          * and the second, holding only fragments. */
 373         if (skb_has_frag_list(head)) {
 374                 struct sk_buff *clone;
 375                 int i, plen = 0;
 376
 377                 clone = alloc_skb(0, GFP_ATOMIC);
 378                 if (clone == NULL)
 379                         return false;
 380
 381                 clone->next = head->next;
 382                 head->next = clone;
 383                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
 384                 skb_frag_list_init(head);
 385                 for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
 386                         plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
 387                 clone->len = clone->data_len = head->data_len - plen;
 388                 head->data_len -= clone->len;
 389                 head->len -= clone->len;
 390                 clone->csum = 0;
 391                 clone->ip_summed = head->ip_summed;
 392
 393                 add_frag_mem_limit(fq->q.net, clone->truesize);
 394         }
 395
 396         /* morph head into last received skb: prev.
 397          *
 398          * This allows callers of ipv6 conntrack defrag to continue
 399          * to use the last skb(frag) passed into the reasm engine.
 400          * The last skb frag 'silently' turns into the full reassembled skb.
 401          *
 402          * Since prev is also part of q->fragments we have to clone it first.
 403          */
 404         if (head != prev) {
 405                 struct sk_buff *iter;
 406
 407                 fp = skb_clone(prev, GFP_ATOMIC);
 408                 if (!fp)
 409                         return false;
 410
 411                 fp->next = prev->next;
 412
 413                 iter = head;
 414                 while (iter) {
 415                         if (iter->next == prev) {
 416                                 iter->next = fp;
 417                                 break;
 418                         }
 419                         iter = iter->next;
 420                 }
 421
 422                 skb_morph(prev, head);
 423                 prev->next = head->next;
 424                 consume_skb(head);
 425                 head = prev;
 426         }
 427
 428         /* We have to remove fragment header from datagram and to relocate
 429          * header in order to calculate ICV correctly. */
 430         skb_network_header(head)[fq->nhoffset] = skb_transport_header(head)[0];
 431         memmove(head->head + sizeof(struct frag_hdr), head->head,
 432                 (head->data - head->head) - sizeof(struct frag_hdr));
 433         head->mac_header += sizeof(struct frag_hdr);
 434         head->network_header += sizeof(struct frag_hdr);
 435
 436         skb_shinfo(head)->frag_list = head->next;
 437         skb_reset_transport_header(head);
 438         skb_push(head, head->data - skb_network_header(head));
 439
 440         for (fp = head->next; fp; fp = fp->next) {
 441                 head->data_len += fp->len;
 442                 head->len += fp->len;
 443                 if (head->ip_summed != fp->ip_summed)
 444                         head->ip_summed = CHECKSUM_NONE;
 445                 else if (head->ip_summed == CHECKSUM_COMPLETE)
 446                         head->csum = csum_add(head->csum, fp->csum);
 447                 head->truesize += fp->truesize;
 448                 fp->sk = NULL;
 449         }
 450         sub_frag_mem_limit(fq->q.net, head->truesize);
 451
 452         head->ignore_df = 1;
 453         skb_mark_not_on_list(head);
 454         head->dev = dev;
 455         head->tstamp = fq->q.stamp;
 456         ipv6_hdr(head)->payload_len = htons(payload_len);
 457         ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn);
 458         IP6CB(head)->frag_max_size = sizeof(struct ipv6hdr) + fq->q.max_size;
 459
 460         /* Yes, and fold redundant checksum back. 8) */
 461         if (head->ip_summed == CHECKSUM_COMPLETE)
 462                 head->csum = csum_partial(skb_network_header(head),
 463                                           skb_network_header_len(head),
 464                                           head->csum);
 465
 466         fq->q.fragments = NULL;
 467         fq->q.rb_fragments = RB_ROOT;
 468         fq->q.fragments_tail = NULL;
 469
 470         return true;
 471 }
 472
 473 /*
 474  * find the header just before Fragment Header.
 475  *
 476  * if success return 0 and set ...
 477  * (*prevhdrp): the value of "Next Header Field" in the header
 478  *              just before Fragment Header.
 479  * (*prevhoff): the offset of "Next Header Field" in the header
 480  *              just before Fragment Header.
 481  * (*fhoff)   : the offset of Fragment Header.
 482  *
 483  * Based on ipv6_skip_hdr() in net/ipv6/exthdr.c
 484  *
 485  */
 486 static int
 487 find_prev_fhdr(struct sk_buff *skb, u8 *prevhdrp, int *prevhoff, int *fhoff)
 488 {
 489         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 490         const int netoff = skb_network_offset(skb);
 491         u8 prev_nhoff = netoff + offsetof(struct ipv6hdr, nexthdr);
 492         int start = netoff + sizeof(struct ipv6hdr);
 493         int len = skb->len - start;
 494         u8 prevhdr = NEXTHDR_IPV6;
 495
 496         while (nexthdr != NEXTHDR_FRAGMENT) {
 497                 struct ipv6_opt_hdr hdr;
 498                 int hdrlen;
 499
 500                 if (!ipv6_ext_hdr(nexthdr)) {
 501                         return -1;
 502                 }
 503                 if (nexthdr == NEXTHDR_NONE) {
 504                         pr_debug("next header is none\n");
 505                         return -1;
 506                 }
 507                 if (len < (int)sizeof(struct ipv6_opt_hdr)) {
 508                         pr_debug("too short\n");
 509                         return -1;
 510                 }
 511                 if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
 512                         BUG();
 513                 if (nexthdr == NEXTHDR_AUTH)
 514                         hdrlen = (hdr.hdrlen+2)<<2;
 515                 else
 516                         hdrlen = ipv6_optlen(&hdr);
 517
 518                 prevhdr = nexthdr;
 519                 prev_nhoff = start;
 520
 521                 nexthdr = hdr.nexthdr;
 522                 len -= hdrlen;
 523                 start += hdrlen;
 524         }
 525
 526         if (len < 0)
 527                 return -1;
 528
 529         *prevhdrp = prevhdr;
 530         *prevhoff = prev_nhoff;
 531         *fhoff = start;
 532
 533         return 0;
 534 }
 535
 536 int nf_ct_frag6_gather(struct net *net, struct sk_buff *skb, u32 user)
 537 {
 538         u16 savethdr = skb->transport_header;
 539         struct net_device *dev = skb->dev;
 540         int fhoff, nhoff, ret;
 541         struct frag_hdr *fhdr;
 542         struct frag_queue *fq;
 543         struct ipv6hdr *hdr;
 544         u8 prevhdr;
 545
 546         /* Jumbo payload inhibits frag. header */
 547         if (ipv6_hdr(skb)->payload_len == 0) {
 548                 pr_debug("payload len = 0\n");
 549                 return 0;
 550         }
 551
 552         if (find_prev_fhdr(skb, &prevhdr, &nhoff, &fhoff) < 0)
 553                 return 0;
 554
 555         if (!pskb_may_pull(skb, fhoff + sizeof(*fhdr)))
 556                 return -ENOMEM;
 557
 558         skb_set_transport_header(skb, fhoff);
 559         hdr = ipv6_hdr(skb);
 560         fhdr = (struct frag_hdr *)skb_transport_header(skb);
 561
 562         if (skb->len - skb_network_offset(skb) < IPV6_MIN_MTU &&
 563             fhdr->frag_off & htons(IP6_MF))
 564                 return -EINVAL;
 565
 566         skb_orphan(skb);
 567         fq = fq_find(net, fhdr->identification, user, hdr,
 568                      skb->dev ? skb->dev->ifindex : 0);
 569         if (fq == NULL) {
 570                 pr_debug("Can't find and can't create new queue\n");
 571                 return -ENOMEM;
 572         }
 573
 574         spin_lock_bh(&fq->q.lock);
 575
 576         ret = nf_ct_frag6_queue(fq, skb, fhdr, nhoff);
 577         if (ret < 0) {
 578                 if (ret == -EPROTO) {
 579                         skb->transport_header = savethdr;
 580                         ret = 0;
 581                 }
 582                 goto out_unlock;
 583         }
 584
 585         /* after queue has assumed skb ownership, only 0 or -EINPROGRESS
 586          * must be returned.
 587          */
 588         ret = -EINPROGRESS;
 589         if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
 590             fq->q.meat == fq->q.len) {
 591                 unsigned long orefdst = skb->_skb_refdst;
 592
 593                 skb->_skb_refdst = 0UL;
 594                 if (nf_ct_frag6_reasm(fq, skb, dev))
 595                         ret = 0;
 596                 skb->_skb_refdst = orefdst;
 597         } else {
 598                 skb_dst_drop(skb);
 599         }
 600
 601 out_unlock:
 602         spin_unlock_bh(&fq->q.lock);
 603         inet_frag_put(&fq->q);
 604         return ret;
 605 }
 606 EXPORT_SYMBOL_GPL(nf_ct_frag6_gather);
 607
 608 static int nf_ct_net_init(struct net *net)
 609 {
 610         int res;
 611
 612         net->nf_frag.frags.high_thresh = IPV6_FRAG_HIGH_THRESH;
 613         net->nf_frag.frags.low_thresh = IPV6_FRAG_LOW_THRESH;
 614         net->nf_frag.frags.timeout = IPV6_FRAG_TIMEOUT;
 615         net->nf_frag.frags.f = &nf_frags;
 616
 617         res = inet_frags_init_net(&net->nf_frag.frags);
 618         if (res < 0)
 619                 return res;
 620         res = nf_ct_frag6_sysctl_register(net);
 621         if (res < 0)
 622                 inet_frags_exit_net(&net->nf_frag.frags);
 623         return res;
 624 }
 625
 626 static void nf_ct_net_exit(struct net *net)
 627 {
 628         nf_ct_frags6_sysctl_unregister(net);
 629         inet_frags_exit_net(&net->nf_frag.frags);
 630 }
 631
 632 static struct pernet_operations nf_ct_net_ops = {
 633         .init = nf_ct_net_init,
 634         .exit = nf_ct_net_exit,
 635 };
 636
 637 static const struct rhashtable_params nfct_rhash_params = {
 638         .head_offset            = offsetof(struct inet_frag_queue, node),
 639         .hashfn                 = ip6frag_key_hashfn,
 640         .obj_hashfn             = ip6frag_obj_hashfn,
 641         .obj_cmpfn              = ip6frag_obj_cmpfn,
 642         .automatic_shrinking    = true,
 643 };
 644
 645 int nf_ct_frag6_init(void)
 646 {
 647         int ret = 0;
 648
 649         nf_frags.constructor = ip6frag_init;
 650         nf_frags.destructor = NULL;
 651         nf_frags.qsize = sizeof(struct frag_queue);
 652         nf_frags.frag_expire = nf_ct_frag6_expire;
 653         nf_frags.frags_cache_name = nf_frags_cache_name;
 654         nf_frags.rhash_params = nfct_rhash_params;
 655         ret = inet_frags_init(&nf_frags);
 656         if (ret)
 657                 goto out;
 658         ret = register_pernet_subsys(&nf_ct_net_ops);
 659         if (ret)
 660                 inet_frags_fini(&nf_frags);
 661
 662 out:
 663         return ret;
 664 }
 665
 666 void nf_ct_frag6_cleanup(void)
 667 {
 668         unregister_pernet_subsys(&nf_ct_net_ops);
 669         inet_frags_fini(&nf_frags);
 670 }