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 #include <linux/errno.h>
  18 #include <linux/types.h>
  19 #include <linux/string.h>
  20 #include <linux/socket.h>
  21 #include <linux/sockios.h>
  22 #include <linux/jiffies.h>
  23 #include <linux/net.h>
  24 #include <linux/list.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/in6.h>
  27 #include <linux/ipv6.h>
  28 #include <linux/icmpv6.h>
  29 #include <linux/random.h>
  30 #include <linux/slab.h>
  31
  32 #include <net/sock.h>
  33 #include <net/snmp.h>
  34 #include <net/inet_frag.h>
  35
  36 #include <net/ipv6.h>
  37 #include <net/protocol.h>
  38 #include <net/transp_v6.h>
  39 #include <net/rawv6.h>
  40 #include <net/ndisc.h>
  41 #include <net/addrconf.h>
  42 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
  43 #include <linux/sysctl.h>
  44 #include <linux/netfilter.h>
  45 #include <linux/netfilter_ipv6.h>
  46 #include <linux/kernel.h>
  47 #include <linux/module.h>
  48 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
  49
  50
  51 struct nf_ct_frag6_skb_cb
  52 {
  53         struct inet6_skb_parm   h;
  54         int                     offset;
  55         struct sk_buff          *orig;
  56 };
  57
  58 #define NFCT_FRAG6_CB(skb)      ((struct nf_ct_frag6_skb_cb*)((skb)->cb))
  59
  60 static struct inet_frags nf_frags;
  61
  62 #ifdef CONFIG_SYSCTL
  63 static struct ctl_table nf_ct_frag6_sysctl_table[] = {
  64         {
  65                 .procname       = "nf_conntrack_frag6_timeout",
  66                 .data           = &init_net.nf_frag.frags.timeout,
  67                 .maxlen         = sizeof(unsigned int),
  68                 .mode           = 0644,
  69                 .proc_handler   = proc_dointvec_jiffies,
  70         },
  71         {
  72                 .procname       = "nf_conntrack_frag6_low_thresh",
  73                 .data           = &init_net.nf_frag.frags.low_thresh,
  74                 .maxlen         = sizeof(unsigned int),
  75                 .mode           = 0644,
  76                 .proc_handler   = proc_dointvec,
  77         },
  78         {
  79                 .procname       = "nf_conntrack_frag6_high_thresh",
  80                 .data           = &init_net.nf_frag.frags.high_thresh,
  81                 .maxlen         = sizeof(unsigned int),
  82                 .mode           = 0644,
  83                 .proc_handler   = proc_dointvec,
  84         },
  85         { }
  86 };
  87
  88 static int nf_ct_frag6_sysctl_register(struct net *net)
  89 {
  90         struct ctl_table *table;
  91         struct ctl_table_header *hdr;
  92
  93         table = nf_ct_frag6_sysctl_table;
  94         if (!net_eq(net, &init_net)) {
  95                 table = kmemdup(table, sizeof(nf_ct_frag6_sysctl_table),
  96                                 GFP_KERNEL);
  97                 if (table == NULL)
  98                         goto err_alloc;
  99
 100                 table[0].data = &net->ipv6.frags.high_thresh;
 101                 table[1].data = &net->ipv6.frags.low_thresh;
 102                 table[2].data = &net->ipv6.frags.timeout;
 103         }
 104
 105         hdr = register_net_sysctl(net, "net/netfilter", table);
 106         if (hdr == NULL)
 107                 goto err_reg;
 108
 109         net->nf_frag.sysctl.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.sysctl.frags_hdr->ctl_table_arg;
 124         unregister_net_sysctl_table(net->nf_frag.sysctl.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 unsigned int nf_hashfn(struct inet_frag_queue *q)
 140 {
 141         const struct frag_queue *nq;
 142
 143         nq = container_of(q, struct frag_queue, q);
 144         return inet6_hash_frag(nq->id, &nq->saddr, &nq->daddr, nf_frags.rnd);
 145 }
 146
 147 static void nf_skb_free(struct sk_buff *skb)
 148 {
 149         if (NFCT_FRAG6_CB(skb)->orig)
 150                 kfree_skb(NFCT_FRAG6_CB(skb)->orig);
 151 }
 152
 153 static void nf_ct_frag6_expire(unsigned long data)
 154 {
 155         struct frag_queue *fq;
 156         struct net *net;
 157
 158         fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
 159         net = container_of(fq->q.net, struct net, nf_frag.frags);
 160
 161         ip6_expire_frag_queue(net, fq, &nf_frags);
 162 }
 163
 164 /* Creation primitives. */
 165 static inline struct frag_queue *fq_find(struct net *net, __be32 id,
 166                                          u32 user, struct in6_addr *src,
 167                                          struct in6_addr *dst)
 168 {
 169         struct inet_frag_queue *q;
 170         struct ip6_create_arg arg;
 171         unsigned int hash;
 172
 173         arg.id = id;
 174         arg.user = user;
 175         arg.src = src;
 176         arg.dst = dst;
 177
 178         read_lock_bh(&nf_frags.lock);
 179         hash = inet6_hash_frag(id, src, dst, nf_frags.rnd);
 180
 181         q = inet_frag_find(&net->nf_frag.frags, &nf_frags, &arg, hash);
 182         local_bh_enable();
 183         if (q == NULL)
 184                 goto oom;
 185
 186         return container_of(q, struct frag_queue, q);
 187
 188 oom:
 189         return NULL;
 190 }
 191
 192
 193 static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb,
 194                              const struct frag_hdr *fhdr, int nhoff)
 195 {
 196         struct sk_buff *prev, *next;
 197         unsigned int payload_len;
 198         int offset, end;
 199
 200         if (fq->q.last_in & INET_FRAG_COMPLETE) {
 201                 pr_debug("Already completed\n");
 202                 goto err;
 203         }
 204
 205         payload_len = ntohs(ipv6_hdr(skb)->payload_len);
 206
 207         offset = ntohs(fhdr->frag_off) & ~0x7;
 208         end = offset + (payload_len -
 209                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
 210
 211         if ((unsigned int)end > IPV6_MAXPLEN) {
 212                 pr_debug("offset is too large.\n");
 213                 return -1;
 214         }
 215
 216         if (skb->ip_summed == CHECKSUM_COMPLETE) {
 217                 const unsigned char *nh = skb_network_header(skb);
 218                 skb->csum = csum_sub(skb->csum,
 219                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
 220                                                   0));
 221         }
 222
 223         /* Is this the final fragment? */
 224         if (!(fhdr->frag_off & htons(IP6_MF))) {
 225                 /* If we already have some bits beyond end
 226                  * or have different end, the segment is corrupted.
 227                  */
 228                 if (end < fq->q.len ||
 229                     ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len)) {
 230                         pr_debug("already received last fragment\n");
 231                         goto err;
 232                 }
 233                 fq->q.last_in |= INET_FRAG_LAST_IN;
 234                 fq->q.len = end;
 235         } else {
 236                 /* Check if the fragment is rounded to 8 bytes.
 237                  * Required by the RFC.
 238                  */
 239                 if (end & 0x7) {
 240                         /* RFC2460 says always send parameter problem in
 241                          * this case. -DaveM
 242                          */
 243                         pr_debug("end of fragment not rounded to 8 bytes.\n");
 244                         return -1;
 245                 }
 246                 if (end > fq->q.len) {
 247                         /* Some bits beyond end -> corruption. */
 248                         if (fq->q.last_in & INET_FRAG_LAST_IN) {
 249                                 pr_debug("last packet already reached.\n");
 250                                 goto err;
 251                         }
 252                         fq->q.len = end;
 253                 }
 254         }
 255
 256         if (end == offset)
 257                 goto err;
 258
 259         /* Point into the IP datagram 'data' part. */
 260         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) {
 261                 pr_debug("queue: message is too short.\n");
 262                 goto err;
 263         }
 264         if (pskb_trim_rcsum(skb, end - offset)) {
 265                 pr_debug("Can't trim\n");
 266                 goto err;
 267         }
 268
 269         /* Find out which fragments are in front and at the back of us
 270          * in the chain of fragments so far.  We must know where to put
 271          * this fragment, right?
 272          */
 273         prev = fq->q.fragments_tail;
 274         if (!prev || NFCT_FRAG6_CB(prev)->offset < offset) {
 275                 next = NULL;
 276                 goto found;
 277         }
 278         prev = NULL;
 279         for (next = fq->q.fragments; next != NULL; next = next->next) {
 280                 if (NFCT_FRAG6_CB(next)->offset >= offset)
 281                         break;  /* bingo! */
 282                 prev = next;
 283         }
 284
 285 found:
 286         /* RFC5722, Section 4:
 287          *                                  When reassembling an IPv6 datagram, if
 288          *   one or more its constituent fragments is determined to be an
 289          *   overlapping fragment, the entire datagram (and any constituent
 290          *   fragments, including those not yet received) MUST be silently
 291          *   discarded.
 292          */
 293
 294         /* Check for overlap with preceding fragment. */
 295         if (prev &&
 296             (NFCT_FRAG6_CB(prev)->offset + prev->len) > offset)
 297                 goto discard_fq;
 298
 299         /* Look for overlap with succeeding segment. */
 300         if (next && NFCT_FRAG6_CB(next)->offset < end)
 301                 goto discard_fq;
 302
 303         NFCT_FRAG6_CB(skb)->offset = offset;
 304
 305         /* Insert this fragment in the chain of fragments. */
 306         skb->next = next;
 307         if (!next)
 308                 fq->q.fragments_tail = skb;
 309         if (prev)
 310                 prev->next = skb;
 311         else
 312                 fq->q.fragments = skb;
 313
 314         skb->dev = NULL;
 315         fq->q.stamp = skb->tstamp;
 316         fq->q.meat += skb->len;
 317         if (payload_len > fq->q.max_size)
 318                 fq->q.max_size = payload_len;
 319         atomic_add(skb->truesize, &fq->q.net->mem);
 320
 321         /* The first fragment.
 322          * nhoffset is obtained from the first fragment, of course.
 323          */
 324         if (offset == 0) {
 325                 fq->nhoffset = nhoff;
 326                 fq->q.last_in |= INET_FRAG_FIRST_IN;
 327         }
 328         write_lock(&nf_frags.lock);
 329         list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list);
 330         write_unlock(&nf_frags.lock);
 331         return 0;
 332
 333 discard_fq:
 334         inet_frag_kill(&fq->q, &nf_frags);
 335 err:
 336         return -1;
 337 }
 338
 339 /*
 340  *      Check if this packet is complete.
 341  *      Returns NULL on failure by any reason, and pointer
 342  *      to current nexthdr field in reassembled frame.
 343  *
 344  *      It is called with locked fq, and caller must check that
 345  *      queue is eligible for reassembly i.e. it is not COMPLETE,
 346  *      the last and the first frames arrived and all the bits are here.
 347  */
 348 static struct sk_buff *
 349 nf_ct_frag6_reasm(struct frag_queue *fq, struct net_device *dev)
 350 {
 351         struct sk_buff *fp, *op, *head = fq->q.fragments;
 352         int    payload_len;
 353
 354         inet_frag_kill(&fq->q, &nf_frags);
 355
 356         WARN_ON(head == NULL);
 357         WARN_ON(NFCT_FRAG6_CB(head)->offset != 0);
 358
 359         /* Unfragmented part is taken from the first segment. */
 360         payload_len = ((head->data - skb_network_header(head)) -
 361                        sizeof(struct ipv6hdr) + fq->q.len -
 362                        sizeof(struct frag_hdr));
 363         if (payload_len > IPV6_MAXPLEN) {
 364                 pr_debug("payload len is too large.\n");
 365                 goto out_oversize;
 366         }
 367
 368         /* Head of list must not be cloned. */
 369         if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) {
 370                 pr_debug("skb is cloned but can't expand head");
 371                 goto out_oom;
 372         }
 373
 374         /* If the first fragment is fragmented itself, we split
 375          * it to two chunks: the first with data and paged part
 376          * and the second, holding only fragments. */
 377         if (skb_has_frag_list(head)) {
 378                 struct sk_buff *clone;
 379                 int i, plen = 0;
 380
 381                 clone = alloc_skb(0, GFP_ATOMIC);
 382                 if (clone == NULL)
 383                         goto out_oom;
 384
 385                 clone->next = head->next;
 386                 head->next = clone;
 387                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
 388                 skb_frag_list_init(head);
 389                 for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
 390                         plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
 391                 clone->len = clone->data_len = head->data_len - plen;
 392                 head->data_len -= clone->len;
 393                 head->len -= clone->len;
 394                 clone->csum = 0;
 395                 clone->ip_summed = head->ip_summed;
 396
 397                 NFCT_FRAG6_CB(clone)->orig = NULL;
 398                 atomic_add(clone->truesize, &fq->q.net->mem);
 399         }
 400
 401         /* We have to remove fragment header from datagram and to relocate
 402          * header in order to calculate ICV correctly. */
 403         skb_network_header(head)[fq->nhoffset] = skb_transport_header(head)[0];
 404         memmove(head->head + sizeof(struct frag_hdr), head->head,
 405                 (head->data - head->head) - sizeof(struct frag_hdr));
 406         head->mac_header += sizeof(struct frag_hdr);
 407         head->network_header += sizeof(struct frag_hdr);
 408
 409         skb_shinfo(head)->frag_list = head->next;
 410         skb_reset_transport_header(head);
 411         skb_push(head, head->data - skb_network_header(head));
 412
 413         for (fp=head->next; fp; fp = fp->next) {
 414                 head->data_len += fp->len;
 415                 head->len += fp->len;
 416                 if (head->ip_summed != fp->ip_summed)
 417                         head->ip_summed = CHECKSUM_NONE;
 418                 else if (head->ip_summed == CHECKSUM_COMPLETE)
 419                         head->csum = csum_add(head->csum, fp->csum);
 420                 head->truesize += fp->truesize;
 421         }
 422         atomic_sub(head->truesize, &fq->q.net->mem);
 423
 424         head->local_df = 1;
 425         head->next = NULL;
 426         head->dev = dev;
 427         head->tstamp = fq->q.stamp;
 428         ipv6_hdr(head)->payload_len = htons(payload_len);
 429         IP6CB(head)->frag_max_size = sizeof(struct ipv6hdr) + fq->q.max_size;
 430
 431         /* Yes, and fold redundant checksum back. 8) */
 432         if (head->ip_summed == CHECKSUM_COMPLETE)
 433                 head->csum = csum_partial(skb_network_header(head),
 434                                           skb_network_header_len(head),
 435                                           head->csum);
 436
 437         fq->q.fragments = NULL;
 438         fq->q.fragments_tail = NULL;
 439
 440         /* all original skbs are linked into the NFCT_FRAG6_CB(head).orig */
 441         fp = skb_shinfo(head)->frag_list;
 442         if (fp && NFCT_FRAG6_CB(fp)->orig == NULL)
 443                 /* at above code, head skb is divided into two skbs. */
 444                 fp = fp->next;
 445
 446         op = NFCT_FRAG6_CB(head)->orig;
 447         for (; fp; fp = fp->next) {
 448                 struct sk_buff *orig = NFCT_FRAG6_CB(fp)->orig;
 449
 450                 op->next = orig;
 451                 op = orig;
 452                 NFCT_FRAG6_CB(fp)->orig = NULL;
 453         }
 454
 455         return head;
 456
 457 out_oversize:
 458         net_dbg_ratelimited("nf_ct_frag6_reasm: payload len = %d\n",
 459                             payload_len);
 460         goto out_fail;
 461 out_oom:
 462         net_dbg_ratelimited("nf_ct_frag6_reasm: no memory for reassembly\n");
 463 out_fail:
 464         return NULL;
 465 }
 466
 467 /*
 468  * find the header just before Fragment Header.
 469  *
 470  * if success return 0 and set ...
 471  * (*prevhdrp): the value of "Next Header Field" in the header
 472  *              just before Fragment Header.
 473  * (*prevhoff): the offset of "Next Header Field" in the header
 474  *              just before Fragment Header.
 475  * (*fhoff)   : the offset of Fragment Header.
 476  *
 477  * Based on ipv6_skip_hdr() in net/ipv6/exthdr.c
 478  *
 479  */
 480 static int
 481 find_prev_fhdr(struct sk_buff *skb, u8 *prevhdrp, int *prevhoff, int *fhoff)
 482 {
 483         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 484         const int netoff = skb_network_offset(skb);
 485         u8 prev_nhoff = netoff + offsetof(struct ipv6hdr, nexthdr);
 486         int start = netoff + sizeof(struct ipv6hdr);
 487         int len = skb->len - start;
 488         u8 prevhdr = NEXTHDR_IPV6;
 489
 490         while (nexthdr != NEXTHDR_FRAGMENT) {
 491                 struct ipv6_opt_hdr hdr;
 492                 int hdrlen;
 493
 494                 if (!ipv6_ext_hdr(nexthdr)) {
 495                         return -1;
 496                 }
 497                 if (nexthdr == NEXTHDR_NONE) {
 498                         pr_debug("next header is none\n");
 499                         return -1;
 500                 }
 501                 if (len < (int)sizeof(struct ipv6_opt_hdr)) {
 502                         pr_debug("too short\n");
 503                         return -1;
 504                 }
 505                 if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
 506                         BUG();
 507                 if (nexthdr == NEXTHDR_AUTH)
 508                         hdrlen = (hdr.hdrlen+2)<<2;
 509                 else
 510                         hdrlen = ipv6_optlen(&hdr);
 511
 512                 prevhdr = nexthdr;
 513                 prev_nhoff = start;
 514
 515                 nexthdr = hdr.nexthdr;
 516                 len -= hdrlen;
 517                 start += hdrlen;
 518         }
 519
 520         if (len < 0)
 521                 return -1;
 522
 523         *prevhdrp = prevhdr;
 524         *prevhoff = prev_nhoff;
 525         *fhoff = start;
 526
 527         return 0;
 528 }
 529
 530 struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb, u32 user)
 531 {
 532         struct sk_buff *clone;
 533         struct net_device *dev = skb->dev;
 534         struct net *net = skb_dst(skb) ? dev_net(skb_dst(skb)->dev)
 535                                        : dev_net(skb->dev);
 536         struct frag_hdr *fhdr;
 537         struct frag_queue *fq;
 538         struct ipv6hdr *hdr;
 539         int fhoff, nhoff;
 540         u8 prevhdr;
 541         struct sk_buff *ret_skb = NULL;
 542
 543         /* Jumbo payload inhibits frag. header */
 544         if (ipv6_hdr(skb)->payload_len == 0) {
 545                 pr_debug("payload len = 0\n");
 546                 return skb;
 547         }
 548
 549         if (find_prev_fhdr(skb, &prevhdr, &nhoff, &fhoff) < 0)
 550                 return skb;
 551
 552         clone = skb_clone(skb, GFP_ATOMIC);
 553         if (clone == NULL) {
 554                 pr_debug("Can't clone skb\n");
 555                 return skb;
 556         }
 557
 558         NFCT_FRAG6_CB(clone)->orig = skb;
 559
 560         if (!pskb_may_pull(clone, fhoff + sizeof(*fhdr))) {
 561                 pr_debug("message is too short.\n");
 562                 goto ret_orig;
 563         }
 564
 565         skb_set_transport_header(clone, fhoff);
 566         hdr = ipv6_hdr(clone);
 567         fhdr = (struct frag_hdr *)skb_transport_header(clone);
 568
 569         local_bh_disable();
 570         inet_frag_evictor(&net->nf_frag.frags, &nf_frags, false);
 571         local_bh_enable();
 572
 573         fq = fq_find(net, fhdr->identification, user, &hdr->saddr, &hdr->daddr);
 574         if (fq == NULL) {
 575                 pr_debug("Can't find and can't create new queue\n");
 576                 goto ret_orig;
 577         }
 578
 579         spin_lock_bh(&fq->q.lock);
 580
 581         if (nf_ct_frag6_queue(fq, clone, fhdr, nhoff) < 0) {
 582                 spin_unlock_bh(&fq->q.lock);
 583                 pr_debug("Can't insert skb to queue\n");
 584                 inet_frag_put(&fq->q, &nf_frags);
 585                 goto ret_orig;
 586         }
 587
 588         if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
 589             fq->q.meat == fq->q.len) {
 590                 ret_skb = nf_ct_frag6_reasm(fq, dev);
 591                 if (ret_skb == NULL)
 592                         pr_debug("Can't reassemble fragmented packets\n");
 593         }
 594         spin_unlock_bh(&fq->q.lock);
 595
 596         inet_frag_put(&fq->q, &nf_frags);
 597         return ret_skb;
 598
 599 ret_orig:
 600         kfree_skb(clone);
 601         return skb;
 602 }
 603
 604 void nf_ct_frag6_output(unsigned int hooknum, struct sk_buff *skb,
 605                         struct net_device *in, struct net_device *out,
 606                         int (*okfn)(struct sk_buff *))
 607 {
 608         struct sk_buff *s, *s2;
 609         unsigned int ret = 0;
 610
 611         for (s = NFCT_FRAG6_CB(skb)->orig; s;) {
 612                 nf_conntrack_put_reasm(s->nfct_reasm);
 613                 nf_conntrack_get_reasm(skb);
 614                 s->nfct_reasm = skb;
 615
 616                 s2 = s->next;
 617                 s->next = NULL;
 618
 619                 if (ret != -ECANCELED)
 620                         ret = NF_HOOK_THRESH(NFPROTO_IPV6, hooknum, s,
 621                                              in, out, okfn,
 622                                              NF_IP6_PRI_CONNTRACK_DEFRAG + 1);
 623                 else
 624                         kfree_skb(s);
 625
 626                 s = s2;
 627         }
 628         nf_conntrack_put_reasm(skb);
 629 }
 630
 631 static int nf_ct_net_init(struct net *net)
 632 {
 633         net->nf_frag.frags.high_thresh = IPV6_FRAG_HIGH_THRESH;
 634         net->nf_frag.frags.low_thresh = IPV6_FRAG_LOW_THRESH;
 635         net->nf_frag.frags.timeout = IPV6_FRAG_TIMEOUT;
 636         inet_frags_init_net(&net->nf_frag.frags);
 637
 638         return nf_ct_frag6_sysctl_register(net);
 639 }
 640
 641 static void nf_ct_net_exit(struct net *net)
 642 {
 643         nf_ct_frags6_sysctl_unregister(net);
 644         inet_frags_exit_net(&net->nf_frag.frags, &nf_frags);
 645 }
 646
 647 static struct pernet_operations nf_ct_net_ops = {
 648         .init = nf_ct_net_init,
 649         .exit = nf_ct_net_exit,
 650 };
 651
 652 int nf_ct_frag6_init(void)
 653 {
 654         int ret = 0;
 655
 656         nf_frags.hashfn = nf_hashfn;
 657         nf_frags.constructor = ip6_frag_init;
 658         nf_frags.destructor = NULL;
 659         nf_frags.skb_free = nf_skb_free;
 660         nf_frags.qsize = sizeof(struct frag_queue);
 661         nf_frags.match = ip6_frag_match;
 662         nf_frags.frag_expire = nf_ct_frag6_expire;
 663         nf_frags.secret_interval = 10 * 60 * HZ;
 664         inet_frags_init(&nf_frags);
 665
 666         ret = register_pernet_subsys(&nf_ct_net_ops);
 667         if (ret)
 668                 inet_frags_fini(&nf_frags);
 669
 670         return ret;
 671 }
 672
 673 void nf_ct_frag6_cleanup(void)
 674 {
 675         unregister_pernet_subsys(&nf_ct_net_ops);
 676         inet_frags_fini(&nf_frags);
 677 }