err.no Git - linux-2.6/blob - 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 static void nf_frag_free(struct inet_frag_queue *q)
 134 {
 135         kfree(container_of(q, struct nf_ct_frag6_queue, q));
 136 }
 137
 138 /* Destruction primitives. */
 139
 140 static __inline__ void fq_put(struct nf_ct_frag6_queue *fq)
 141 {
 142         inet_frag_put(&fq->q, &nf_frags);
 143 }
 144
 145 /* Kill fq entry. It is not destroyed immediately,
 146  * because caller (and someone more) holds reference count.
 147  */
 148 static __inline__ void fq_kill(struct nf_ct_frag6_queue *fq)
 149 {
 150         inet_frag_kill(&fq->q, &nf_frags);
 151 }
 152
 153 static void nf_ct_frag6_evictor(void)
 154 {
 155         inet_frag_evictor(&nf_frags);
 156 }
 157
 158 static void nf_ct_frag6_expire(unsigned long data)
 159 {
 160         struct nf_ct_frag6_queue *fq;
 161
 162         fq = container_of((struct inet_frag_queue *)data,
 163                         struct nf_ct_frag6_queue, q);
 164
 165         spin_lock(&fq->q.lock);
 166
 167         if (fq->q.last_in & COMPLETE)
 168                 goto out;
 169
 170         fq_kill(fq);
 171
 172 out:
 173         spin_unlock(&fq->q.lock);
 174         fq_put(fq);
 175 }
 176
 177 /* Creation primitives. */
 178
 179 static __inline__ struct nf_ct_frag6_queue *
 180 fq_find(__be32 id, struct in6_addr *src, struct in6_addr *dst)
 181 {
 182         struct inet_frag_queue *q;
 183         struct ip6_create_arg arg;
 184         unsigned int hash;
 185
 186         arg.id = id;
 187         arg.src = src;
 188         arg.dst = dst;
 189         hash = ip6qhashfn(id, src, dst);
 190
 191         q = inet_frag_find(&nf_frags, &arg, hash);
 192         if (q == NULL)
 193                 goto oom;
 194
 195         return container_of(q, struct nf_ct_frag6_queue, q);
 196
 197 oom:
 198         pr_debug("Can't alloc new queue\n");
 199         return NULL;
 200 }
 201
 202
 203 static int nf_ct_frag6_queue(struct nf_ct_frag6_queue *fq, struct sk_buff *skb,
 204                              struct frag_hdr *fhdr, int nhoff)
 205 {
 206         struct sk_buff *prev, *next;
 207         int offset, end;
 208
 209         if (fq->q.last_in & COMPLETE) {
 210                 pr_debug("Allready completed\n");
 211                 goto err;
 212         }
 213
 214         offset = ntohs(fhdr->frag_off) & ~0x7;
 215         end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
 216                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
 217
 218         if ((unsigned int)end > IPV6_MAXPLEN) {
 219                 pr_debug("offset is too large.\n");
 220                 return -1;
 221         }
 222
 223         if (skb->ip_summed == CHECKSUM_COMPLETE) {
 224                 const unsigned char *nh = skb_network_header(skb);
 225                 skb->csum = csum_sub(skb->csum,
 226                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
 227                                                   0));
 228         }
 229
 230         /* Is this the final fragment? */
 231         if (!(fhdr->frag_off & htons(IP6_MF))) {
 232                 /* If we already have some bits beyond end
 233                  * or have different end, the segment is corrupted.
 234                  */
 235                 if (end < fq->q.len ||
 236                     ((fq->q.last_in & LAST_IN) && end != fq->q.len)) {
 237                         pr_debug("already received last fragment\n");
 238                         goto err;
 239                 }
 240                 fq->q.last_in |= LAST_IN;
 241                 fq->q.len = end;
 242         } else {
 243                 /* Check if the fragment is rounded to 8 bytes.
 244                  * Required by the RFC.
 245                  */
 246                 if (end & 0x7) {
 247                         /* RFC2460 says always send parameter problem in
 248                          * this case. -DaveM
 249                          */
 250                         pr_debug("end of fragment not rounded to 8 bytes.\n");
 251                         return -1;
 252                 }
 253                 if (end > fq->q.len) {
 254                         /* Some bits beyond end -> corruption. */
 255                         if (fq->q.last_in & LAST_IN) {
 256                                 pr_debug("last packet already reached.\n");
 257                                 goto err;
 258                         }
 259                         fq->q.len = end;
 260                 }
 261         }
 262
 263         if (end == offset)
 264                 goto err;
 265
 266         /* Point into the IP datagram 'data' part. */
 267         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) {
 268                 pr_debug("queue: message is too short.\n");
 269                 goto err;
 270         }
 271         if (pskb_trim_rcsum(skb, end - offset)) {
 272                 pr_debug("Can't trim\n");
 273                 goto err;
 274         }
 275
 276         /* Find out which fragments are in front and at the back of us
 277          * in the chain of fragments so far.  We must know where to put
 278          * this fragment, right?
 279          */
 280         prev = NULL;
 281         for (next = fq->q.fragments; next != NULL; next = next->next) {
 282                 if (NFCT_FRAG6_CB(next)->offset >= offset)
 283                         break;  /* bingo! */
 284                 prev = next;
 285         }
 286
 287         /* We found where to put this one.  Check for overlap with
 288          * preceding fragment, and, if needed, align things so that
 289          * any overlaps are eliminated.
 290          */
 291         if (prev) {
 292                 int i = (NFCT_FRAG6_CB(prev)->offset + prev->len) - offset;
 293
 294                 if (i > 0) {
 295                         offset += i;
 296                         if (end <= offset) {
 297                                 pr_debug("overlap\n");
 298                                 goto err;
 299                         }
 300                         if (!pskb_pull(skb, i)) {
 301                                 pr_debug("Can't pull\n");
 302                                 goto err;
 303                         }
 304                         if (skb->ip_summed != CHECKSUM_UNNECESSARY)
 305                                 skb->ip_summed = CHECKSUM_NONE;
 306                 }
 307         }
 308
 309         /* Look for overlap with succeeding segments.
 310          * If we can merge fragments, do it.
 311          */
 312         while (next && NFCT_FRAG6_CB(next)->offset < end) {
 313                 /* overlap is 'i' bytes */
 314                 int i = end - NFCT_FRAG6_CB(next)->offset;
 315
 316                 if (i < next->len) {
 317                         /* Eat head of the next overlapped fragment
 318                          * and leave the loop. The next ones cannot overlap.
 319                          */
 320                         pr_debug("Eat head of the overlapped parts.: %d", i);
 321                         if (!pskb_pull(next, i))
 322                                 goto err;
 323
 324                         /* next fragment */
 325                         NFCT_FRAG6_CB(next)->offset += i;
 326                         fq->q.meat -= i;
 327                         if (next->ip_summed != CHECKSUM_UNNECESSARY)
 328                                 next->ip_summed = CHECKSUM_NONE;
 329                         break;
 330                 } else {
 331                         struct sk_buff *free_it = next;
 332
 333                         /* Old fragmnet is completely overridden with
 334                          * new one drop it.
 335                          */
 336                         next = next->next;
 337
 338                         if (prev)
 339                                 prev->next = next;
 340                         else
 341                                 fq->q.fragments = next;
 342
 343                         fq->q.meat -= free_it->len;
 344                         frag_kfree_skb(free_it, NULL);
 345                 }
 346         }
 347
 348         NFCT_FRAG6_CB(skb)->offset = offset;
 349
 350         /* Insert this fragment in the chain of fragments. */
 351         skb->next = next;
 352         if (prev)
 353                 prev->next = skb;
 354         else
 355                 fq->q.fragments = skb;
 356
 357         skb->dev = NULL;
 358         fq->q.stamp = skb->tstamp;
 359         fq->q.meat += skb->len;
 360         atomic_add(skb->truesize, &nf_frags.mem);
 361
 362         /* The first fragment.
 363          * nhoffset is obtained from the first fragment, of course.
 364          */
 365         if (offset == 0) {
 366                 fq->nhoffset = nhoff;
 367                 fq->q.last_in |= FIRST_IN;
 368         }
 369         write_lock(&nf_frags.lock);
 370         list_move_tail(&fq->q.lru_list, &nf_frags.lru_list);
 371         write_unlock(&nf_frags.lock);
 372         return 0;
 373
 374 err:
 375         return -1;
 376 }
 377
 378 /*
 379  *      Check if this packet is complete.
 380  *      Returns NULL on failure by any reason, and pointer
 381  *      to current nexthdr field in reassembled frame.
 382  *
 383  *      It is called with locked fq, and caller must check that
 384  *      queue is eligible for reassembly i.e. it is not COMPLETE,
 385  *      the last and the first frames arrived and all the bits are here.
 386  */
 387 static struct sk_buff *
 388 nf_ct_frag6_reasm(struct nf_ct_frag6_queue *fq, struct net_device *dev)
 389 {
 390         struct sk_buff *fp, *op, *head = fq->q.fragments;
 391         int    payload_len;
 392
 393         fq_kill(fq);
 394
 395         BUG_TRAP(head != NULL);
 396         BUG_TRAP(NFCT_FRAG6_CB(head)->offset == 0);
 397
 398         /* Unfragmented part is taken from the first segment. */
 399         payload_len = ((head->data - skb_network_header(head)) -
 400                        sizeof(struct ipv6hdr) + fq->q.len -
 401                        sizeof(struct frag_hdr));
 402         if (payload_len > IPV6_MAXPLEN) {
 403                 pr_debug("payload len is too large.\n");
 404                 goto out_oversize;
 405         }
 406
 407         /* Head of list must not be cloned. */
 408         if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) {
 409                 pr_debug("skb is cloned but can't expand head");
 410                 goto out_oom;
 411         }
 412
 413         /* If the first fragment is fragmented itself, we split
 414          * it to two chunks: the first with data and paged part
 415          * and the second, holding only fragments. */
 416         if (skb_shinfo(head)->frag_list) {
 417                 struct sk_buff *clone;
 418                 int i, plen = 0;
 419
 420                 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) {
 421                         pr_debug("Can't alloc skb\n");
 422                         goto out_oom;
 423                 }
 424                 clone->next = head->next;
 425                 head->next = clone;
 426                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
 427                 skb_shinfo(head)->frag_list = NULL;
 428                 for (i=0; i<skb_shinfo(head)->nr_frags; i++)
 429                         plen += skb_shinfo(head)->frags[i].size;
 430                 clone->len = clone->data_len = head->data_len - plen;
 431                 head->data_len -= clone->len;
 432                 head->len -= clone->len;
 433                 clone->csum = 0;
 434                 clone->ip_summed = head->ip_summed;
 435
 436                 NFCT_FRAG6_CB(clone)->orig = NULL;
 437                 atomic_add(clone->truesize, &nf_frags.mem);
 438         }
 439
 440         /* We have to remove fragment header from datagram and to relocate
 441          * header in order to calculate ICV correctly. */
 442         skb_network_header(head)[fq->nhoffset] = skb_transport_header(head)[0];
 443         memmove(head->head + sizeof(struct frag_hdr), head->head,
 444                 (head->data - head->head) - sizeof(struct frag_hdr));
 445         head->mac_header += sizeof(struct frag_hdr);
 446         head->network_header += sizeof(struct frag_hdr);
 447
 448         skb_shinfo(head)->frag_list = head->next;
 449         skb_reset_transport_header(head);
 450         skb_push(head, head->data - skb_network_header(head));
 451         atomic_sub(head->truesize, &nf_frags.mem);
 452
 453         for (fp=head->next; fp; fp = fp->next) {
 454                 head->data_len += fp->len;
 455                 head->len += fp->len;
 456                 if (head->ip_summed != fp->ip_summed)
 457                         head->ip_summed = CHECKSUM_NONE;
 458                 else if (head->ip_summed == CHECKSUM_COMPLETE)
 459                         head->csum = csum_add(head->csum, fp->csum);
 460                 head->truesize += fp->truesize;
 461                 atomic_sub(fp->truesize, &nf_frags.mem);
 462         }
 463
 464         head->next = NULL;
 465         head->dev = dev;
 466         head->tstamp = fq->q.stamp;
 467         ipv6_hdr(head)->payload_len = htons(payload_len);
 468
 469         /* Yes, and fold redundant checksum back. 8) */
 470         if (head->ip_summed == CHECKSUM_COMPLETE)
 471                 head->csum = csum_partial(skb_network_header(head),
 472                                           skb_network_header_len(head),
 473                                           head->csum);
 474
 475         fq->q.fragments = NULL;
 476
 477         /* all original skbs are linked into the NFCT_FRAG6_CB(head).orig */
 478         fp = skb_shinfo(head)->frag_list;
 479         if (NFCT_FRAG6_CB(fp)->orig == NULL)
 480                 /* at above code, head skb is divided into two skbs. */
 481                 fp = fp->next;
 482
 483         op = NFCT_FRAG6_CB(head)->orig;
 484         for (; fp; fp = fp->next) {
 485                 struct sk_buff *orig = NFCT_FRAG6_CB(fp)->orig;
 486
 487                 op->next = orig;
 488                 op = orig;
 489                 NFCT_FRAG6_CB(fp)->orig = NULL;
 490         }
 491
 492         return head;
 493
 494 out_oversize:
 495         if (net_ratelimit())
 496                 printk(KERN_DEBUG "nf_ct_frag6_reasm: payload len = %d\n", payload_len);
 497         goto out_fail;
 498 out_oom:
 499         if (net_ratelimit())
 500                 printk(KERN_DEBUG "nf_ct_frag6_reasm: no memory for reassembly\n");
 501 out_fail:
 502         return NULL;
 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 (len < (int)sizeof(struct ipv6_opt_hdr)) {
 536                         pr_debug("too short\n");
 537                         return -1;
 538                 }
 539                 if (nexthdr == NEXTHDR_NONE) {
 540                         pr_debug("next header is none\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 struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb)
 569 {
 570         struct sk_buff *clone;
 571         struct net_device *dev = skb->dev;
 572         struct frag_hdr *fhdr;
 573         struct nf_ct_frag6_queue *fq;
 574         struct ipv6hdr *hdr;
 575         int fhoff, nhoff;
 576         u8 prevhdr;
 577         struct sk_buff *ret_skb = NULL;
 578
 579         /* Jumbo payload inhibits frag. header */
 580         if (ipv6_hdr(skb)->payload_len == 0) {
 581                 pr_debug("payload len = 0\n");
 582                 return skb;
 583         }
 584
 585         if (find_prev_fhdr(skb, &prevhdr, &nhoff, &fhoff) < 0)
 586                 return skb;
 587
 588         clone = skb_clone(skb, GFP_ATOMIC);
 589         if (clone == NULL) {
 590                 pr_debug("Can't clone skb\n");
 591                 return skb;
 592         }
 593
 594         NFCT_FRAG6_CB(clone)->orig = skb;
 595
 596         if (!pskb_may_pull(clone, fhoff + sizeof(*fhdr))) {
 597                 pr_debug("message is too short.\n");
 598                 goto ret_orig;
 599         }
 600
 601         skb_set_transport_header(clone, fhoff);
 602         hdr = ipv6_hdr(clone);
 603         fhdr = (struct frag_hdr *)skb_transport_header(clone);
 604
 605         if (!(fhdr->frag_off & htons(0xFFF9))) {
 606                 pr_debug("Invalid fragment offset\n");
 607                 /* It is not a fragmented frame */
 608                 goto ret_orig;
 609         }
 610
 611         if (atomic_read(&nf_frags.mem) > nf_frags_ctl.high_thresh)
 612                 nf_ct_frag6_evictor();
 613
 614         fq = fq_find(fhdr->identification, &hdr->saddr, &hdr->daddr);
 615         if (fq == NULL) {
 616                 pr_debug("Can't find and can't create new queue\n");
 617                 goto ret_orig;
 618         }
 619
 620         spin_lock(&fq->q.lock);
 621
 622         if (nf_ct_frag6_queue(fq, clone, fhdr, nhoff) < 0) {
 623                 spin_unlock(&fq->q.lock);
 624                 pr_debug("Can't insert skb to queue\n");
 625                 fq_put(fq);
 626                 goto ret_orig;
 627         }
 628
 629         if (fq->q.last_in == (FIRST_IN|LAST_IN) && fq->q.meat == fq->q.len) {
 630                 ret_skb = nf_ct_frag6_reasm(fq, dev);
 631                 if (ret_skb == NULL)
 632                         pr_debug("Can't reassemble fragmented packets\n");
 633         }
 634         spin_unlock(&fq->q.lock);
 635
 636         fq_put(fq);
 637         return ret_skb;
 638
 639 ret_orig:
 640         kfree_skb(clone);
 641         return skb;
 642 }
 643
 644 void nf_ct_frag6_output(unsigned int hooknum, struct sk_buff *skb,
 645                         struct net_device *in, struct net_device *out,
 646                         int (*okfn)(struct sk_buff *))
 647 {
 648         struct sk_buff *s, *s2;
 649
 650         for (s = NFCT_FRAG6_CB(skb)->orig; s;) {
 651                 nf_conntrack_put_reasm(s->nfct_reasm);
 652                 nf_conntrack_get_reasm(skb);
 653                 s->nfct_reasm = skb;
 654
 655                 s2 = s->next;
 656                 s->next = NULL;
 657
 658                 NF_HOOK_THRESH(PF_INET6, hooknum, s, in, out, okfn,
 659                                NF_IP6_PRI_CONNTRACK_DEFRAG + 1);
 660                 s = s2;
 661         }
 662         nf_conntrack_put_reasm(skb);
 663 }
 664
 665 int nf_ct_frag6_kfree_frags(struct sk_buff *skb)
 666 {
 667         struct sk_buff *s, *s2;
 668
 669         for (s = NFCT_FRAG6_CB(skb)->orig; s; s = s2) {
 670
 671                 s2 = s->next;
 672                 kfree_skb(s);
 673         }
 674
 675         kfree_skb(skb);
 676
 677         return 0;
 678 }
 679
 680 int nf_ct_frag6_init(void)
 681 {
 682         nf_frags.ctl = &nf_frags_ctl;
 683         nf_frags.hashfn = nf_hashfn;
 684         nf_frags.constructor = ip6_frag_init;
 685         nf_frags.destructor = nf_frag_free;
 686         nf_frags.skb_free = nf_skb_free;
 687         nf_frags.qsize = sizeof(struct nf_ct_frag6_queue);
 688         nf_frags.match = ip6_frag_match;
 689         nf_frags.equal = ip6_frag_equal;
 690         nf_frags.frag_expire = nf_ct_frag6_expire;
 691         inet_frags_init(&nf_frags);
 692
 693         return 0;
 694 }
 695
 696 void nf_ct_frag6_cleanup(void)
 697 {
 698         inet_frags_fini(&nf_frags);
 699
 700         nf_frags_ctl.low_thresh = 0;
 701         nf_ct_frag6_evictor();
 702 }