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/inet_frag.h>
  37
  38 #include <net/ipv6.h>
  39 #include <net/protocol.h>
  40 #include <net/transp_v6.h>
  41 #include <net/rawv6.h>
  42 #include <net/ndisc.h>
  43 #include <net/addrconf.h>
  44 #include <net/inet_ecn.h>
  45 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
  46 #include <linux/sysctl.h>
  47 #include <linux/netfilter.h>
  48 #include <linux/netfilter_ipv6.h>
  49 #include <linux/kernel.h>
  50 #include <linux/module.h>
  51 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
  52
  53 static const char nf_frags_cache_name[] = "nf-frags";
  54
  55 struct nf_ct_frag6_skb_cb
  56 {
  57         struct inet6_skb_parm   h;
  58         int                     offset;
  59 };
  60
  61 #define NFCT_FRAG6_CB(skb)      ((struct nf_ct_frag6_skb_cb *)((skb)->cb))
  62
  63 static struct inet_frags nf_frags;
  64
  65 #ifdef CONFIG_SYSCTL
  66 static int zero;
  67
  68 static struct ctl_table nf_ct_frag6_sysctl_table[] = {
  69         {
  70                 .procname       = "nf_conntrack_frag6_timeout",
  71                 .data           = &init_net.nf_frag.frags.timeout,
  72                 .maxlen         = sizeof(unsigned int),
  73                 .mode           = 0644,
  74                 .proc_handler   = proc_dointvec_jiffies,
  75         },
  76         {
  77                 .procname       = "nf_conntrack_frag6_low_thresh",
  78                 .data           = &init_net.nf_frag.frags.low_thresh,
  79                 .maxlen         = sizeof(unsigned int),
  80                 .mode           = 0644,
  81                 .proc_handler   = proc_dointvec_minmax,
  82                 .extra1         = &zero,
  83                 .extra2         = &init_net.nf_frag.frags.high_thresh
  84         },
  85         {
  86                 .procname       = "nf_conntrack_frag6_high_thresh",
  87                 .data           = &init_net.nf_frag.frags.high_thresh,
  88                 .maxlen         = sizeof(unsigned int),
  89                 .mode           = 0644,
  90                 .proc_handler   = proc_dointvec_minmax,
  91                 .extra1         = &init_net.nf_frag.frags.low_thresh
  92         },
  93         { }
  94 };
  95
  96 static int nf_ct_frag6_sysctl_register(struct net *net)
  97 {
  98         struct ctl_table *table;
  99         struct ctl_table_header *hdr;
 100
 101         table = nf_ct_frag6_sysctl_table;
 102         if (!net_eq(net, &init_net)) {
 103                 table = kmemdup(table, sizeof(nf_ct_frag6_sysctl_table),
 104                                 GFP_KERNEL);
 105                 if (table == NULL)
 106                         goto err_alloc;
 107
 108                 table[0].data = &net->nf_frag.frags.timeout;
 109                 table[1].data = &net->nf_frag.frags.low_thresh;
 110                 table[1].extra2 = &net->nf_frag.frags.high_thresh;
 111                 table[2].data = &net->nf_frag.frags.high_thresh;
 112                 table[2].extra1 = &net->nf_frag.frags.low_thresh;
 113                 table[2].extra2 = &init_net.nf_frag.frags.high_thresh;
 114         }
 115
 116         hdr = register_net_sysctl(net, "net/netfilter", table);
 117         if (hdr == NULL)
 118                 goto err_reg;
 119
 120         net->nf_frag.sysctl.frags_hdr = hdr;
 121         return 0;
 122
 123 err_reg:
 124         if (!net_eq(net, &init_net))
 125                 kfree(table);
 126 err_alloc:
 127         return -ENOMEM;
 128 }
 129
 130 static void __net_exit nf_ct_frags6_sysctl_unregister(struct net *net)
 131 {
 132         struct ctl_table *table;
 133
 134         table = net->nf_frag.sysctl.frags_hdr->ctl_table_arg;
 135         unregister_net_sysctl_table(net->nf_frag.sysctl.frags_hdr);
 136         if (!net_eq(net, &init_net))
 137                 kfree(table);
 138 }
 139
 140 #else
 141 static int nf_ct_frag6_sysctl_register(struct net *net)
 142 {
 143         return 0;
 144 }
 145 static void __net_exit nf_ct_frags6_sysctl_unregister(struct net *net)
 146 {
 147 }
 148 #endif
 149
 150 static inline u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h)
 151 {
 152         return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK);
 153 }
 154
 155 static unsigned int nf_hash_frag(__be32 id, const struct in6_addr *saddr,
 156                                  const struct in6_addr *daddr)
 157 {
 158         net_get_random_once(&nf_frags.rnd, sizeof(nf_frags.rnd));
 159         return jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr),
 160                             (__force u32)id, nf_frags.rnd);
 161 }
 162
 163
 164 static unsigned int nf_hashfn(const struct inet_frag_queue *q)
 165 {
 166         const struct frag_queue *nq;
 167
 168         nq = container_of(q, struct frag_queue, q);
 169         return nf_hash_frag(nq->id, &nq->saddr, &nq->daddr);
 170 }
 171
 172 static void nf_ct_frag6_expire(struct timer_list *t)
 173 {
 174         struct inet_frag_queue *frag = from_timer(frag, t, timer);
 175         struct frag_queue *fq;
 176         struct net *net;
 177
 178         fq = container_of(frag, struct frag_queue, q);
 179         net = container_of(fq->q.net, struct net, nf_frag.frags);
 180
 181         ip6_expire_frag_queue(net, fq, &nf_frags);
 182 }
 183
 184 /* Creation primitives. */
 185 static inline struct frag_queue *fq_find(struct net *net, __be32 id,
 186                                          u32 user, struct in6_addr *src,
 187                                          struct in6_addr *dst, int iif, u8 ecn)
 188 {
 189         struct inet_frag_queue *q;
 190         struct ip6_create_arg arg;
 191         unsigned int hash;
 192
 193         arg.id = id;
 194         arg.user = user;
 195         arg.src = src;
 196         arg.dst = dst;
 197         arg.iif = iif;
 198         arg.ecn = ecn;
 199
 200         local_bh_disable();
 201         hash = nf_hash_frag(id, src, dst);
 202
 203         q = inet_frag_find(&net->nf_frag.frags, &nf_frags, &arg, hash);
 204         local_bh_enable();
 205         if (IS_ERR_OR_NULL(q)) {
 206                 inet_frag_maybe_warn_overflow(q, pr_fmt());
 207                 return NULL;
 208         }
 209         return container_of(q, struct frag_queue, q);
 210 }
 211
 212
 213 static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb,
 214                              const struct frag_hdr *fhdr, int nhoff)
 215 {
 216         struct sk_buff *prev, *next;
 217         unsigned int payload_len;
 218         int offset, end;
 219         u8 ecn;
 220
 221         if (fq->q.flags & INET_FRAG_COMPLETE) {
 222                 pr_debug("Already completed\n");
 223                 goto err;
 224         }
 225
 226         payload_len = ntohs(ipv6_hdr(skb)->payload_len);
 227
 228         offset = ntohs(fhdr->frag_off) & ~0x7;
 229         end = offset + (payload_len -
 230                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
 231
 232         if ((unsigned int)end > IPV6_MAXPLEN) {
 233                 pr_debug("offset is too large.\n");
 234                 return -EINVAL;
 235         }
 236
 237         ecn = ip6_frag_ecn(ipv6_hdr(skb));
 238
 239         if (skb->ip_summed == CHECKSUM_COMPLETE) {
 240                 const unsigned char *nh = skb_network_header(skb);
 241                 skb->csum = csum_sub(skb->csum,
 242                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
 243                                                   0));
 244         }
 245
 246         /* Is this the final fragment? */
 247         if (!(fhdr->frag_off & htons(IP6_MF))) {
 248                 /* If we already have some bits beyond end
 249                  * or have different end, the segment is corrupted.
 250                  */
 251                 if (end < fq->q.len ||
 252                     ((fq->q.flags & INET_FRAG_LAST_IN) && end != fq->q.len)) {
 253                         pr_debug("already received last fragment\n");
 254                         goto err;
 255                 }
 256                 fq->q.flags |= INET_FRAG_LAST_IN;
 257                 fq->q.len = end;
 258         } else {
 259                 /* Check if the fragment is rounded to 8 bytes.
 260                  * Required by the RFC.
 261                  */
 262                 if (end & 0x7) {
 263                         /* RFC2460 says always send parameter problem in
 264                          * this case. -DaveM
 265                          */
 266                         pr_debug("end of fragment not rounded to 8 bytes.\n");
 267                         return -EPROTO;
 268                 }
 269                 if (end > fq->q.len) {
 270                         /* Some bits beyond end -> corruption. */
 271                         if (fq->q.flags & INET_FRAG_LAST_IN) {
 272                                 pr_debug("last packet already reached.\n");
 273                                 goto err;
 274                         }
 275                         fq->q.len = end;
 276                 }
 277         }
 278
 279         if (end == offset)
 280                 goto err;
 281
 282         /* Point into the IP datagram 'data' part. */
 283         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) {
 284                 pr_debug("queue: message is too short.\n");
 285                 goto err;
 286         }
 287         if (pskb_trim_rcsum(skb, end - offset)) {
 288                 pr_debug("Can't trim\n");
 289                 goto err;
 290         }
 291
 292         /* Find out which fragments are in front and at the back of us
 293          * in the chain of fragments so far.  We must know where to put
 294          * this fragment, right?
 295          */
 296         prev = fq->q.fragments_tail;
 297         if (!prev || NFCT_FRAG6_CB(prev)->offset < offset) {
 298                 next = NULL;
 299                 goto found;
 300         }
 301         prev = NULL;
 302         for (next = fq->q.fragments; next != NULL; next = next->next) {
 303                 if (NFCT_FRAG6_CB(next)->offset >= offset)
 304                         break;  /* bingo! */
 305                 prev = next;
 306         }
 307
 308 found:
 309         /* RFC5722, Section 4:
 310          *                                  When reassembling an IPv6 datagram, if
 311          *   one or more its constituent fragments is determined to be an
 312          *   overlapping fragment, the entire datagram (and any constituent
 313          *   fragments, including those not yet received) MUST be silently
 314          *   discarded.
 315          */
 316
 317         /* Check for overlap with preceding fragment. */
 318         if (prev &&
 319             (NFCT_FRAG6_CB(prev)->offset + prev->len) > offset)
 320                 goto discard_fq;
 321
 322         /* Look for overlap with succeeding segment. */
 323         if (next && NFCT_FRAG6_CB(next)->offset < end)
 324                 goto discard_fq;
 325
 326         NFCT_FRAG6_CB(skb)->offset = offset;
 327
 328         /* Insert this fragment in the chain of fragments. */
 329         skb->next = next;
 330         if (!next)
 331                 fq->q.fragments_tail = skb;
 332         if (prev)
 333                 prev->next = skb;
 334         else
 335                 fq->q.fragments = skb;
 336
 337         if (skb->dev) {
 338                 fq->iif = skb->dev->ifindex;
 339                 skb->dev = NULL;
 340         }
 341         fq->q.stamp = skb->tstamp;
 342         fq->q.meat += skb->len;
 343         fq->ecn |= ecn;
 344         if (payload_len > fq->q.max_size)
 345                 fq->q.max_size = payload_len;
 346         add_frag_mem_limit(fq->q.net, skb->truesize);
 347
 348         /* The first fragment.
 349          * nhoffset is obtained from the first fragment, of course.
 350          */
 351         if (offset == 0) {
 352                 fq->nhoffset = nhoff;
 353                 fq->q.flags |= INET_FRAG_FIRST_IN;
 354         }
 355
 356         return 0;
 357
 358 discard_fq:
 359         inet_frag_kill(&fq->q, &nf_frags);
 360 err:
 361         return -EINVAL;
 362 }
 363
 364 /*
 365  *      Check if this packet is complete.
 366  *
 367  *      It is called with locked fq, and caller must check that
 368  *      queue is eligible for reassembly i.e. it is not COMPLETE,
 369  *      the last and the first frames arrived and all the bits are here.
 370  *
 371  *      returns true if *prev skb has been transformed into the reassembled
 372  *      skb, false otherwise.
 373  */
 374 static bool
 375 nf_ct_frag6_reasm(struct frag_queue *fq, struct sk_buff *prev,  struct net_device *dev)
 376 {
 377         struct sk_buff *fp, *head = fq->q.fragments;
 378         int    payload_len;
 379         u8 ecn;
 380
 381         inet_frag_kill(&fq->q, &nf_frags);
 382
 383         WARN_ON(head == NULL);
 384         WARN_ON(NFCT_FRAG6_CB(head)->offset != 0);
 385
 386         ecn = ip_frag_ecn_table[fq->ecn];
 387         if (unlikely(ecn == 0xff))
 388                 return false;
 389
 390         /* Unfragmented part is taken from the first segment. */
 391         payload_len = ((head->data - skb_network_header(head)) -
 392                        sizeof(struct ipv6hdr) + fq->q.len -
 393                        sizeof(struct frag_hdr));
 394         if (payload_len > IPV6_MAXPLEN) {
 395                 net_dbg_ratelimited("nf_ct_frag6_reasm: payload len = %d\n",
 396                                     payload_len);
 397                 return false;
 398         }
 399
 400         /* Head of list must not be cloned. */
 401         if (skb_unclone(head, GFP_ATOMIC))
 402                 return false;
 403
 404         /* If the first fragment is fragmented itself, we split
 405          * it to two chunks: the first with data and paged part
 406          * and the second, holding only fragments. */
 407         if (skb_has_frag_list(head)) {
 408                 struct sk_buff *clone;
 409                 int i, plen = 0;
 410
 411                 clone = alloc_skb(0, GFP_ATOMIC);
 412                 if (clone == NULL)
 413                         return false;
 414
 415                 clone->next = head->next;
 416                 head->next = clone;
 417                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
 418                 skb_frag_list_init(head);
 419                 for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
 420                         plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
 421                 clone->len = clone->data_len = head->data_len - plen;
 422                 head->data_len -= clone->len;
 423                 head->len -= clone->len;
 424                 clone->csum = 0;
 425                 clone->ip_summed = head->ip_summed;
 426
 427                 add_frag_mem_limit(fq->q.net, clone->truesize);
 428         }
 429
 430         /* morph head into last received skb: prev.
 431          *
 432          * This allows callers of ipv6 conntrack defrag to continue
 433          * to use the last skb(frag) passed into the reasm engine.
 434          * The last skb frag 'silently' turns into the full reassembled skb.
 435          *
 436          * Since prev is also part of q->fragments we have to clone it first.
 437          */
 438         if (head != prev) {
 439                 struct sk_buff *iter;
 440
 441                 fp = skb_clone(prev, GFP_ATOMIC);
 442                 if (!fp)
 443                         return false;
 444
 445                 fp->next = prev->next;
 446
 447                 iter = head;
 448                 while (iter) {
 449                         if (iter->next == prev) {
 450                                 iter->next = fp;
 451                                 break;
 452                         }
 453                         iter = iter->next;
 454                 }
 455
 456                 skb_morph(prev, head);
 457                 prev->next = head->next;
 458                 consume_skb(head);
 459                 head = prev;
 460         }
 461
 462         /* We have to remove fragment header from datagram and to relocate
 463          * header in order to calculate ICV correctly. */
 464         skb_network_header(head)[fq->nhoffset] = skb_transport_header(head)[0];
 465         memmove(head->head + sizeof(struct frag_hdr), head->head,
 466                 (head->data - head->head) - sizeof(struct frag_hdr));
 467         head->mac_header += sizeof(struct frag_hdr);
 468         head->network_header += sizeof(struct frag_hdr);
 469
 470         skb_shinfo(head)->frag_list = head->next;
 471         skb_reset_transport_header(head);
 472         skb_push(head, head->data - skb_network_header(head));
 473
 474         for (fp = head->next; fp; fp = fp->next) {
 475                 head->data_len += fp->len;
 476                 head->len += fp->len;
 477                 if (head->ip_summed != fp->ip_summed)
 478                         head->ip_summed = CHECKSUM_NONE;
 479                 else if (head->ip_summed == CHECKSUM_COMPLETE)
 480                         head->csum = csum_add(head->csum, fp->csum);
 481                 head->truesize += fp->truesize;
 482         }
 483         sub_frag_mem_limit(fq->q.net, head->truesize);
 484
 485         head->ignore_df = 1;
 486         head->next = NULL;
 487         head->dev = dev;
 488         head->tstamp = fq->q.stamp;
 489         ipv6_hdr(head)->payload_len = htons(payload_len);
 490         ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn);
 491         IP6CB(head)->frag_max_size = sizeof(struct ipv6hdr) + fq->q.max_size;
 492
 493         /* Yes, and fold redundant checksum back. 8) */
 494         if (head->ip_summed == CHECKSUM_COMPLETE)
 495                 head->csum = csum_partial(skb_network_header(head),
 496                                           skb_network_header_len(head),
 497                                           head->csum);
 498
 499         fq->q.fragments = NULL;
 500         fq->q.fragments_tail = NULL;
 501
 502         return true;
 503 }
 504
 505 /*
 506  * find the header just before Fragment Header.
 507  *
 508  * if success return 0 and set ...
 509  * (*prevhdrp): the value of "Next Header Field" in the header
 510  *              just before Fragment Header.
 511  * (*prevhoff): the offset of "Next Header Field" in the header
 512  *              just before Fragment Header.
 513  * (*fhoff)   : the offset of Fragment Header.
 514  *
 515  * Based on ipv6_skip_hdr() in net/ipv6/exthdr.c
 516  *
 517  */
 518 static int
 519 find_prev_fhdr(struct sk_buff *skb, u8 *prevhdrp, int *prevhoff, int *fhoff)
 520 {
 521         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 522         const int netoff = skb_network_offset(skb);
 523         u8 prev_nhoff = netoff + offsetof(struct ipv6hdr, nexthdr);
 524         int start = netoff + sizeof(struct ipv6hdr);
 525         int len = skb->len - start;
 526         u8 prevhdr = NEXTHDR_IPV6;
 527
 528         while (nexthdr != NEXTHDR_FRAGMENT) {
 529                 struct ipv6_opt_hdr hdr;
 530                 int hdrlen;
 531
 532                 if (!ipv6_ext_hdr(nexthdr)) {
 533                         return -1;
 534                 }
 535                 if (nexthdr == NEXTHDR_NONE) {
 536                         pr_debug("next header is none\n");
 537                         return -1;
 538                 }
 539                 if (len < (int)sizeof(struct ipv6_opt_hdr)) {
 540                         pr_debug("too short\n");
 541                         return -1;
 542                 }
 543                 if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
 544                         BUG();
 545                 if (nexthdr == NEXTHDR_AUTH)
 546                         hdrlen = (hdr.hdrlen+2)<<2;
 547                 else
 548                         hdrlen = ipv6_optlen(&hdr);
 549
 550                 prevhdr = nexthdr;
 551                 prev_nhoff = start;
 552
 553                 nexthdr = hdr.nexthdr;
 554                 len -= hdrlen;
 555                 start += hdrlen;
 556         }
 557
 558         if (len < 0)
 559                 return -1;
 560
 561         *prevhdrp = prevhdr;
 562         *prevhoff = prev_nhoff;
 563         *fhoff = start;
 564
 565         return 0;
 566 }
 567
 568 int nf_ct_frag6_gather(struct net *net, struct sk_buff *skb, u32 user)
 569 {
 570         u16 savethdr = skb->transport_header;
 571         struct net_device *dev = skb->dev;
 572         int fhoff, nhoff, ret;
 573         struct frag_hdr *fhdr;
 574         struct frag_queue *fq;
 575         struct ipv6hdr *hdr;
 576         u8 prevhdr;
 577
 578         /* Jumbo payload inhibits frag. header */
 579         if (ipv6_hdr(skb)->payload_len == 0) {
 580                 pr_debug("payload len = 0\n");
 581                 return 0;
 582         }
 583
 584         if (find_prev_fhdr(skb, &prevhdr, &nhoff, &fhoff) < 0)
 585                 return 0;
 586
 587         if (!pskb_may_pull(skb, fhoff + sizeof(*fhdr)))
 588                 return -ENOMEM;
 589
 590         skb_set_transport_header(skb, fhoff);
 591         hdr = ipv6_hdr(skb);
 592         fhdr = (struct frag_hdr *)skb_transport_header(skb);
 593
 594         skb_orphan(skb);
 595         fq = fq_find(net, fhdr->identification, user, &hdr->saddr, &hdr->daddr,
 596                      skb->dev ? skb->dev->ifindex : 0, ip6_frag_ecn(hdr));
 597         if (fq == NULL) {
 598                 pr_debug("Can't find and can't create new queue\n");
 599                 return -ENOMEM;
 600         }
 601
 602         spin_lock_bh(&fq->q.lock);
 603
 604         ret = nf_ct_frag6_queue(fq, skb, fhdr, nhoff);
 605         if (ret < 0) {
 606                 if (ret == -EPROTO) {
 607                         skb->transport_header = savethdr;
 608                         ret = 0;
 609                 }
 610                 goto out_unlock;
 611         }
 612
 613         /* after queue has assumed skb ownership, only 0 or -EINPROGRESS
 614          * must be returned.
 615          */
 616         ret = -EINPROGRESS;
 617         if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
 618             fq->q.meat == fq->q.len &&
 619             nf_ct_frag6_reasm(fq, skb, dev))
 620                 ret = 0;
 621
 622 out_unlock:
 623         spin_unlock_bh(&fq->q.lock);
 624         inet_frag_put(&fq->q, &nf_frags);
 625         return ret;
 626 }
 627 EXPORT_SYMBOL_GPL(nf_ct_frag6_gather);
 628
 629 static int nf_ct_net_init(struct net *net)
 630 {
 631         net->nf_frag.frags.high_thresh = IPV6_FRAG_HIGH_THRESH;
 632         net->nf_frag.frags.low_thresh = IPV6_FRAG_LOW_THRESH;
 633         net->nf_frag.frags.timeout = IPV6_FRAG_TIMEOUT;
 634         inet_frags_init_net(&net->nf_frag.frags);
 635
 636         return nf_ct_frag6_sysctl_register(net);
 637 }
 638
 639 static void nf_ct_net_exit(struct net *net)
 640 {
 641         nf_ct_frags6_sysctl_unregister(net);
 642         inet_frags_exit_net(&net->nf_frag.frags, &nf_frags);
 643 }
 644
 645 static struct pernet_operations nf_ct_net_ops = {
 646         .init = nf_ct_net_init,
 647         .exit = nf_ct_net_exit,
 648 };
 649
 650 int nf_ct_frag6_init(void)
 651 {
 652         int ret = 0;
 653
 654         nf_frags.hashfn = nf_hashfn;
 655         nf_frags.constructor = ip6_frag_init;
 656         nf_frags.destructor = NULL;
 657         nf_frags.qsize = sizeof(struct frag_queue);
 658         nf_frags.match = ip6_frag_match;
 659         nf_frags.frag_expire = nf_ct_frag6_expire;
 660         nf_frags.frags_cache_name = nf_frags_cache_name;
 661         ret = inet_frags_init(&nf_frags);
 662         if (ret)
 663                 goto out;
 664         ret = register_pernet_subsys(&nf_ct_net_ops);
 665         if (ret)
 666                 inet_frags_fini(&nf_frags);
 667
 668 out:
 669         return ret;
 670 }
 671
 672 void nf_ct_frag6_cleanup(void)
 673 {
 674         unregister_pernet_subsys(&nf_ct_net_ops);
 675         inet_frags_fini(&nf_frags);
 676 }