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/jhash.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 <linux/sysctl.h>
  43 #include <linux/netfilter.h>
  44 #include <linux/netfilter_ipv6.h>
  45 #include <linux/kernel.h>
  46 #include <linux/module.h>
  47
  48 #define NF_CT_FRAG6_HIGH_THRESH 262144 /* == 256*1024 */
  49 #define NF_CT_FRAG6_LOW_THRESH 196608  /* == 192*1024 */
  50 #define NF_CT_FRAG6_TIMEOUT IPV6_FRAG_TIMEOUT
  51
  52 struct nf_ct_frag6_skb_cb
  53 {
  54         struct inet6_skb_parm   h;
  55         int                     offset;
  56         struct sk_buff          *orig;
  57 };
  58
  59 #define NFCT_FRAG6_CB(skb)      ((struct nf_ct_frag6_skb_cb*)((skb)->cb))
  60
  61 struct nf_ct_frag6_queue
  62 {
  63         struct inet_frag_queue  q;
  64
  65         __be32                  id;             /* fragment id          */
  66         struct in6_addr         saddr;
  67         struct in6_addr         daddr;
  68
  69         unsigned int            csum;
  70         __u16                   nhoffset;
  71 };
  72
  73 struct inet_frags_ctl nf_frags_ctl __read_mostly = {
  74         .high_thresh     = 256 * 1024,
  75         .low_thresh      = 192 * 1024,
  76         .timeout         = IPV6_FRAG_TIMEOUT,
  77         .secret_interval = 10 * 60 * HZ,
  78 };
  79
  80 static struct inet_frags nf_frags;
  81
  82 static unsigned int ip6qhashfn(__be32 id, struct in6_addr *saddr,
  83                                struct in6_addr *daddr)
  84 {
  85         u32 a, b, c;
  86
  87         a = (__force u32)saddr->s6_addr32[0];
  88         b = (__force u32)saddr->s6_addr32[1];
  89         c = (__force u32)saddr->s6_addr32[2];
  90
  91         a += JHASH_GOLDEN_RATIO;
  92         b += JHASH_GOLDEN_RATIO;
  93         c += nf_frags.rnd;
  94         __jhash_mix(a, b, c);
  95
  96         a += (__force u32)saddr->s6_addr32[3];
  97         b += (__force u32)daddr->s6_addr32[0];
  98         c += (__force u32)daddr->s6_addr32[1];
  99         __jhash_mix(a, b, c);
 100
 101         a += (__force u32)daddr->s6_addr32[2];
 102         b += (__force u32)daddr->s6_addr32[3];
 103         c += (__force u32)id;
 104         __jhash_mix(a, b, c);
 105
 106         return c & (INETFRAGS_HASHSZ - 1);
 107 }
 108
 109 static unsigned int nf_hashfn(struct inet_frag_queue *q)
 110 {
 111         struct nf_ct_frag6_queue *nq;
 112
 113         nq = container_of(q, struct nf_ct_frag6_queue, q);
 114         return ip6qhashfn(nq->id, &nq->saddr, &nq->daddr);
 115 }
 116
 117 static void nf_skb_free(struct sk_buff *skb)
 118 {
 119         if (NFCT_FRAG6_CB(skb)->orig)
 120                 kfree_skb(NFCT_FRAG6_CB(skb)->orig);
 121 }
 122
 123 /* Memory Tracking Functions. */
 124 static inline void frag_kfree_skb(struct sk_buff *skb, unsigned int *work)
 125 {
 126         if (work)
 127                 *work -= skb->truesize;
 128         atomic_sub(skb->truesize, &nf_frags.mem);
 129         nf_skb_free(skb);
 130         kfree_skb(skb);
 131 }
 132
 133 /* Destruction primitives. */
 134
 135 static __inline__ void fq_put(struct nf_ct_frag6_queue *fq)
 136 {
 137         inet_frag_put(&fq->q, &nf_frags);
 138 }
 139
 140 /* Kill fq entry. It is not destroyed immediately,
 141  * because caller (and someone more) holds reference count.
 142  */
 143 static __inline__ void fq_kill(struct nf_ct_frag6_queue *fq)
 144 {
 145         inet_frag_kill(&fq->q, &nf_frags);
 146 }
 147
 148 static void nf_ct_frag6_evictor(void)
 149 {
 150         inet_frag_evictor(&nf_frags);
 151 }
 152
 153 static void nf_ct_frag6_expire(unsigned long data)
 154 {
 155         struct nf_ct_frag6_queue *fq;
 156
 157         fq = container_of((struct inet_frag_queue *)data,
 158                         struct nf_ct_frag6_queue, q);
 159
 160         spin_lock(&fq->q.lock);
 161
 162         if (fq->q.last_in & COMPLETE)
 163                 goto out;
 164
 165         fq_kill(fq);
 166
 167 out:
 168         spin_unlock(&fq->q.lock);
 169         fq_put(fq);
 170 }
 171
 172 /* Creation primitives. */
 173
 174 static __inline__ struct nf_ct_frag6_queue *
 175 fq_find(__be32 id, struct in6_addr *src, struct in6_addr *dst)
 176 {
 177         struct inet_frag_queue *q;
 178         struct ip6_create_arg arg;
 179         unsigned int hash;
 180
 181         arg.id = id;
 182         arg.src = src;
 183         arg.dst = dst;
 184         hash = ip6qhashfn(id, src, dst);
 185
 186         q = inet_frag_find(&nf_frags, &arg, hash);
 187         if (q == NULL)
 188                 goto oom;
 189
 190         return container_of(q, struct nf_ct_frag6_queue, q);
 191
 192 oom:
 193         pr_debug("Can't alloc new queue\n");
 194         return NULL;
 195 }
 196
 197
 198 static int nf_ct_frag6_queue(struct nf_ct_frag6_queue *fq, struct sk_buff *skb,
 199                              struct frag_hdr *fhdr, int nhoff)
 200 {
 201         struct sk_buff *prev, *next;
 202         int offset, end;
 203
 204         if (fq->q.last_in & COMPLETE) {
 205                 pr_debug("Allready completed\n");
 206                 goto err;
 207         }
 208
 209         offset = ntohs(fhdr->frag_off) & ~0x7;
 210         end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
 211                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
 212
 213         if ((unsigned int)end > IPV6_MAXPLEN) {
 214                 pr_debug("offset is too large.\n");
 215                 return -1;
 216         }
 217
 218         if (skb->ip_summed == CHECKSUM_COMPLETE) {
 219                 const unsigned char *nh = skb_network_header(skb);
 220                 skb->csum = csum_sub(skb->csum,
 221                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
 222                                                   0));
 223         }
 224
 225         /* Is this the final fragment? */
 226         if (!(fhdr->frag_off & htons(IP6_MF))) {
 227                 /* If we already have some bits beyond end
 228                  * or have different end, the segment is corrupted.
 229                  */
 230                 if (end < fq->q.len ||
 231                     ((fq->q.last_in & LAST_IN) && end != fq->q.len)) {
 232                         pr_debug("already received last fragment\n");
 233                         goto err;
 234                 }
 235                 fq->q.last_in |= LAST_IN;
 236                 fq->q.len = end;
 237         } else {
 238                 /* Check if the fragment is rounded to 8 bytes.
 239                  * Required by the RFC.
 240                  */
 241                 if (end & 0x7) {
 242                         /* RFC2460 says always send parameter problem in
 243                          * this case. -DaveM
 244                          */
 245                         pr_debug("end of fragment not rounded to 8 bytes.\n");
 246                         return -1;
 247                 }
 248                 if (end > fq->q.len) {
 249                         /* Some bits beyond end -> corruption. */
 250                         if (fq->q.last_in & LAST_IN) {
 251                                 pr_debug("last packet already reached.\n");
 252                                 goto err;
 253                         }
 254                         fq->q.len = end;
 255                 }
 256         }
 257
 258         if (end == offset)
 259                 goto err;
 260
 261         /* Point into the IP datagram 'data' part. */
 262         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) {
 263                 pr_debug("queue: message is too short.\n");
 264                 goto err;
 265         }
 266         if (pskb_trim_rcsum(skb, end - offset)) {
 267                 pr_debug("Can't trim\n");
 268                 goto err;
 269         }
 270
 271         /* Find out which fragments are in front and at the back of us
 272          * in the chain of fragments so far.  We must know where to put
 273          * this fragment, right?
 274          */
 275         prev = NULL;
 276         for (next = fq->q.fragments; next != NULL; next = next->next) {
 277                 if (NFCT_FRAG6_CB(next)->offset >= offset)
 278                         break;  /* bingo! */
 279                 prev = next;
 280         }
 281
 282         /* We found where to put this one.  Check for overlap with
 283          * preceding fragment, and, if needed, align things so that
 284          * any overlaps are eliminated.
 285          */
 286         if (prev) {
 287                 int i = (NFCT_FRAG6_CB(prev)->offset + prev->len) - offset;
 288
 289                 if (i > 0) {
 290                         offset += i;
 291                         if (end <= offset) {
 292                                 pr_debug("overlap\n");
 293                                 goto err;
 294                         }
 295                         if (!pskb_pull(skb, i)) {
 296                                 pr_debug("Can't pull\n");
 297                                 goto err;
 298                         }
 299                         if (skb->ip_summed != CHECKSUM_UNNECESSARY)
 300                                 skb->ip_summed = CHECKSUM_NONE;
 301                 }
 302         }
 303
 304         /* Look for overlap with succeeding segments.
 305          * If we can merge fragments, do it.
 306          */
 307         while (next && NFCT_FRAG6_CB(next)->offset < end) {
 308                 /* overlap is 'i' bytes */
 309                 int i = end - NFCT_FRAG6_CB(next)->offset;
 310
 311                 if (i < next->len) {
 312                         /* Eat head of the next overlapped fragment
 313                          * and leave the loop. The next ones cannot overlap.
 314                          */
 315                         pr_debug("Eat head of the overlapped parts.: %d", i);
 316                         if (!pskb_pull(next, i))
 317                                 goto err;
 318
 319                         /* next fragment */
 320                         NFCT_FRAG6_CB(next)->offset += i;
 321                         fq->q.meat -= i;
 322                         if (next->ip_summed != CHECKSUM_UNNECESSARY)
 323                                 next->ip_summed = CHECKSUM_NONE;
 324                         break;
 325                 } else {
 326                         struct sk_buff *free_it = next;
 327
 328                         /* Old fragmnet is completely overridden with
 329                          * new one drop it.
 330                          */
 331                         next = next->next;
 332
 333                         if (prev)
 334                                 prev->next = next;
 335                         else
 336                                 fq->q.fragments = next;
 337
 338                         fq->q.meat -= free_it->len;
 339                         frag_kfree_skb(free_it, NULL);
 340                 }
 341         }
 342
 343         NFCT_FRAG6_CB(skb)->offset = offset;
 344
 345         /* Insert this fragment in the chain of fragments. */
 346         skb->next = next;
 347         if (prev)
 348                 prev->next = skb;
 349         else
 350                 fq->q.fragments = skb;
 351
 352         skb->dev = NULL;
 353         fq->q.stamp = skb->tstamp;
 354         fq->q.meat += skb->len;
 355         atomic_add(skb->truesize, &nf_frags.mem);
 356
 357         /* The first fragment.
 358          * nhoffset is obtained from the first fragment, of course.
 359          */
 360         if (offset == 0) {
 361                 fq->nhoffset = nhoff;
 362                 fq->q.last_in |= FIRST_IN;
 363         }
 364         write_lock(&nf_frags.lock);
 365         list_move_tail(&fq->q.lru_list, &nf_frags.lru_list);
 366         write_unlock(&nf_frags.lock);
 367         return 0;
 368
 369 err:
 370         return -1;
 371 }
 372
 373 /*
 374  *      Check if this packet is complete.
 375  *      Returns NULL on failure by any reason, and pointer
 376  *      to current nexthdr field in reassembled frame.
 377  *
 378  *      It is called with locked fq, and caller must check that
 379  *      queue is eligible for reassembly i.e. it is not COMPLETE,
 380  *      the last and the first frames arrived and all the bits are here.
 381  */
 382 static struct sk_buff *
 383 nf_ct_frag6_reasm(struct nf_ct_frag6_queue *fq, struct net_device *dev)
 384 {
 385         struct sk_buff *fp, *op, *head = fq->q.fragments;
 386         int    payload_len;
 387
 388         fq_kill(fq);
 389
 390         BUG_TRAP(head != NULL);
 391         BUG_TRAP(NFCT_FRAG6_CB(head)->offset == 0);
 392
 393         /* Unfragmented part is taken from the first segment. */
 394         payload_len = ((head->data - skb_network_header(head)) -
 395                        sizeof(struct ipv6hdr) + fq->q.len -
 396                        sizeof(struct frag_hdr));
 397         if (payload_len > IPV6_MAXPLEN) {
 398                 pr_debug("payload len is too large.\n");
 399                 goto out_oversize;
 400         }
 401
 402         /* Head of list must not be cloned. */
 403         if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) {
 404                 pr_debug("skb is cloned but can't expand head");
 405                 goto out_oom;
 406         }
 407
 408         /* If the first fragment is fragmented itself, we split
 409          * it to two chunks: the first with data and paged part
 410          * and the second, holding only fragments. */
 411         if (skb_shinfo(head)->frag_list) {
 412                 struct sk_buff *clone;
 413                 int i, plen = 0;
 414
 415                 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) {
 416                         pr_debug("Can't alloc skb\n");
 417                         goto out_oom;
 418                 }
 419                 clone->next = head->next;
 420                 head->next = clone;
 421                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
 422                 skb_shinfo(head)->frag_list = NULL;
 423                 for (i=0; i<skb_shinfo(head)->nr_frags; i++)
 424                         plen += skb_shinfo(head)->frags[i].size;
 425                 clone->len = clone->data_len = head->data_len - plen;
 426                 head->data_len -= clone->len;
 427                 head->len -= clone->len;
 428                 clone->csum = 0;
 429                 clone->ip_summed = head->ip_summed;
 430
 431                 NFCT_FRAG6_CB(clone)->orig = NULL;
 432                 atomic_add(clone->truesize, &nf_frags.mem);
 433         }
 434
 435         /* We have to remove fragment header from datagram and to relocate
 436          * header in order to calculate ICV correctly. */
 437         skb_network_header(head)[fq->nhoffset] = skb_transport_header(head)[0];
 438         memmove(head->head + sizeof(struct frag_hdr), head->head,
 439                 (head->data - head->head) - sizeof(struct frag_hdr));
 440         head->mac_header += sizeof(struct frag_hdr);
 441         head->network_header += sizeof(struct frag_hdr);
 442
 443         skb_shinfo(head)->frag_list = head->next;
 444         skb_reset_transport_header(head);
 445         skb_push(head, head->data - skb_network_header(head));
 446         atomic_sub(head->truesize, &nf_frags.mem);
 447
 448         for (fp=head->next; fp; fp = fp->next) {
 449                 head->data_len += fp->len;
 450                 head->len += fp->len;
 451                 if (head->ip_summed != fp->ip_summed)
 452                         head->ip_summed = CHECKSUM_NONE;
 453                 else if (head->ip_summed == CHECKSUM_COMPLETE)
 454                         head->csum = csum_add(head->csum, fp->csum);
 455                 head->truesize += fp->truesize;
 456                 atomic_sub(fp->truesize, &nf_frags.mem);
 457         }
 458
 459         head->next = NULL;
 460         head->dev = dev;
 461         head->tstamp = fq->q.stamp;
 462         ipv6_hdr(head)->payload_len = htons(payload_len);
 463
 464         /* Yes, and fold redundant checksum back. 8) */
 465         if (head->ip_summed == CHECKSUM_COMPLETE)
 466                 head->csum = csum_partial(skb_network_header(head),
 467                                           skb_network_header_len(head),
 468                                           head->csum);
 469
 470         fq->q.fragments = NULL;
 471
 472         /* all original skbs are linked into the NFCT_FRAG6_CB(head).orig */
 473         fp = skb_shinfo(head)->frag_list;
 474         if (NFCT_FRAG6_CB(fp)->orig == NULL)
 475                 /* at above code, head skb is divided into two skbs. */
 476                 fp = fp->next;
 477
 478         op = NFCT_FRAG6_CB(head)->orig;
 479         for (; fp; fp = fp->next) {
 480                 struct sk_buff *orig = NFCT_FRAG6_CB(fp)->orig;
 481
 482                 op->next = orig;
 483                 op = orig;
 484                 NFCT_FRAG6_CB(fp)->orig = NULL;
 485         }
 486
 487         return head;
 488
 489 out_oversize:
 490         if (net_ratelimit())
 491                 printk(KERN_DEBUG "nf_ct_frag6_reasm: payload len = %d\n", payload_len);
 492         goto out_fail;
 493 out_oom:
 494         if (net_ratelimit())
 495                 printk(KERN_DEBUG "nf_ct_frag6_reasm: no memory for reassembly\n");
 496 out_fail:
 497         return NULL;
 498 }
 499
 500 /*
 501  * find the header just before Fragment Header.
 502  *
 503  * if success return 0 and set ...
 504  * (*prevhdrp): the value of "Next Header Field" in the header
 505  *              just before Fragment Header.
 506  * (*prevhoff): the offset of "Next Header Field" in the header
 507  *              just before Fragment Header.
 508  * (*fhoff)   : the offset of Fragment Header.
 509  *
 510  * Based on ipv6_skip_hdr() in net/ipv6/exthdr.c
 511  *
 512  */
 513 static int
 514 find_prev_fhdr(struct sk_buff *skb, u8 *prevhdrp, int *prevhoff, int *fhoff)
 515 {
 516         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 517         const int netoff = skb_network_offset(skb);
 518         u8 prev_nhoff = netoff + offsetof(struct ipv6hdr, nexthdr);
 519         int start = netoff + sizeof(struct ipv6hdr);
 520         int len = skb->len - start;
 521         u8 prevhdr = NEXTHDR_IPV6;
 522
 523         while (nexthdr != NEXTHDR_FRAGMENT) {
 524                 struct ipv6_opt_hdr hdr;
 525                 int hdrlen;
 526
 527                 if (!ipv6_ext_hdr(nexthdr)) {
 528                         return -1;
 529                 }
 530                 if (len < (int)sizeof(struct ipv6_opt_hdr)) {
 531                         pr_debug("too short\n");
 532                         return -1;
 533                 }
 534                 if (nexthdr == NEXTHDR_NONE) {
 535                         pr_debug("next header is none\n");
 536                         return -1;
 537                 }
 538                 if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
 539                         BUG();
 540                 if (nexthdr == NEXTHDR_AUTH)
 541                         hdrlen = (hdr.hdrlen+2)<<2;
 542                 else
 543                         hdrlen = ipv6_optlen(&hdr);
 544
 545                 prevhdr = nexthdr;
 546                 prev_nhoff = start;
 547
 548                 nexthdr = hdr.nexthdr;
 549                 len -= hdrlen;
 550                 start += hdrlen;
 551         }
 552
 553         if (len < 0)
 554                 return -1;
 555
 556         *prevhdrp = prevhdr;
 557         *prevhoff = prev_nhoff;
 558         *fhoff = start;
 559
 560         return 0;
 561 }
 562
 563 struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb)
 564 {
 565         struct sk_buff *clone;
 566         struct net_device *dev = skb->dev;
 567         struct frag_hdr *fhdr;
 568         struct nf_ct_frag6_queue *fq;
 569         struct ipv6hdr *hdr;
 570         int fhoff, nhoff;
 571         u8 prevhdr;
 572         struct sk_buff *ret_skb = NULL;
 573
 574         /* Jumbo payload inhibits frag. header */
 575         if (ipv6_hdr(skb)->payload_len == 0) {
 576                 pr_debug("payload len = 0\n");
 577                 return skb;
 578         }
 579
 580         if (find_prev_fhdr(skb, &prevhdr, &nhoff, &fhoff) < 0)
 581                 return skb;
 582
 583         clone = skb_clone(skb, GFP_ATOMIC);
 584         if (clone == NULL) {
 585                 pr_debug("Can't clone skb\n");
 586                 return skb;
 587         }
 588
 589         NFCT_FRAG6_CB(clone)->orig = skb;
 590
 591         if (!pskb_may_pull(clone, fhoff + sizeof(*fhdr))) {
 592                 pr_debug("message is too short.\n");
 593                 goto ret_orig;
 594         }
 595
 596         skb_set_transport_header(clone, fhoff);
 597         hdr = ipv6_hdr(clone);
 598         fhdr = (struct frag_hdr *)skb_transport_header(clone);
 599
 600         if (!(fhdr->frag_off & htons(0xFFF9))) {
 601                 pr_debug("Invalid fragment offset\n");
 602                 /* It is not a fragmented frame */
 603                 goto ret_orig;
 604         }
 605
 606         if (atomic_read(&nf_frags.mem) > nf_frags_ctl.high_thresh)
 607                 nf_ct_frag6_evictor();
 608
 609         fq = fq_find(fhdr->identification, &hdr->saddr, &hdr->daddr);
 610         if (fq == NULL) {
 611                 pr_debug("Can't find and can't create new queue\n");
 612                 goto ret_orig;
 613         }
 614
 615         spin_lock(&fq->q.lock);
 616
 617         if (nf_ct_frag6_queue(fq, clone, fhdr, nhoff) < 0) {
 618                 spin_unlock(&fq->q.lock);
 619                 pr_debug("Can't insert skb to queue\n");
 620                 fq_put(fq);
 621                 goto ret_orig;
 622         }
 623
 624         if (fq->q.last_in == (FIRST_IN|LAST_IN) && fq->q.meat == fq->q.len) {
 625                 ret_skb = nf_ct_frag6_reasm(fq, dev);
 626                 if (ret_skb == NULL)
 627                         pr_debug("Can't reassemble fragmented packets\n");
 628         }
 629         spin_unlock(&fq->q.lock);
 630
 631         fq_put(fq);
 632         return ret_skb;
 633
 634 ret_orig:
 635         kfree_skb(clone);
 636         return skb;
 637 }
 638
 639 void nf_ct_frag6_output(unsigned int hooknum, struct sk_buff *skb,
 640                         struct net_device *in, struct net_device *out,
 641                         int (*okfn)(struct sk_buff *))
 642 {
 643         struct sk_buff *s, *s2;
 644
 645         for (s = NFCT_FRAG6_CB(skb)->orig; s;) {
 646                 nf_conntrack_put_reasm(s->nfct_reasm);
 647                 nf_conntrack_get_reasm(skb);
 648                 s->nfct_reasm = skb;
 649
 650                 s2 = s->next;
 651                 s->next = NULL;
 652
 653                 NF_HOOK_THRESH(PF_INET6, hooknum, s, in, out, okfn,
 654                                NF_IP6_PRI_CONNTRACK_DEFRAG + 1);
 655                 s = s2;
 656         }
 657         nf_conntrack_put_reasm(skb);
 658 }
 659
 660 int nf_ct_frag6_kfree_frags(struct sk_buff *skb)
 661 {
 662         struct sk_buff *s, *s2;
 663
 664         for (s = NFCT_FRAG6_CB(skb)->orig; s; s = s2) {
 665
 666                 s2 = s->next;
 667                 kfree_skb(s);
 668         }
 669
 670         kfree_skb(skb);
 671
 672         return 0;
 673 }
 674
 675 int nf_ct_frag6_init(void)
 676 {
 677         nf_frags.ctl = &nf_frags_ctl;
 678         nf_frags.hashfn = nf_hashfn;
 679         nf_frags.constructor = ip6_frag_init;
 680         nf_frags.destructor = NULL;
 681         nf_frags.skb_free = nf_skb_free;
 682         nf_frags.qsize = sizeof(struct nf_ct_frag6_queue);
 683         nf_frags.match = ip6_frag_match;
 684         nf_frags.frag_expire = nf_ct_frag6_expire;
 685         inet_frags_init(&nf_frags);
 686
 687         return 0;
 688 }
 689
 690 void nf_ct_frag6_cleanup(void)
 691 {
 692         inet_frags_fini(&nf_frags);
 693
 694         nf_frags_ctl.low_thresh = 0;
 695         nf_ct_frag6_evictor();
 696 }