SAFE public projects git trees. - safe/jmp/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 <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
  49 #define NF_CT_FRAG6_HIGH_THRESH 262144 /* == 256*1024 */
  50 #define NF_CT_FRAG6_LOW_THRESH 196608  /* == 192*1024 */
  51 #define NF_CT_FRAG6_TIMEOUT IPV6_FRAG_TIMEOUT
  52
  53 struct nf_ct_frag6_skb_cb
  54 {
  55         struct inet6_skb_parm   h;
  56         int                     offset;
  57         struct sk_buff          *orig;
  58 };
  59
  60 #define NFCT_FRAG6_CB(skb)      ((struct nf_ct_frag6_skb_cb*)((skb)->cb))
  61
  62 struct nf_ct_frag6_queue
  63 {
  64         struct inet_frag_queue  q;
  65
  66         __be32                  id;             /* fragment id          */
  67         struct in6_addr         saddr;
  68         struct in6_addr         daddr;
  69
  70         unsigned int            csum;
  71         __u16                   nhoffset;
  72 };
  73
  74 static struct inet_frags nf_frags;
  75 static struct netns_frags nf_init_frags;
  76
  77 #ifdef CONFIG_SYSCTL
  78 struct ctl_table nf_ct_ipv6_sysctl_table[] = {
  79         {
  80                 .procname       = "nf_conntrack_frag6_timeout",
  81                 .data           = &nf_init_frags.timeout,
  82                 .maxlen         = sizeof(unsigned int),
  83                 .mode           = 0644,
  84                 .proc_handler   = &proc_dointvec_jiffies,
  85         },
  86         {
  87                 .ctl_name       = NET_NF_CONNTRACK_FRAG6_LOW_THRESH,
  88                 .procname       = "nf_conntrack_frag6_low_thresh",
  89                 .data           = &nf_init_frags.low_thresh,
  90                 .maxlen         = sizeof(unsigned int),
  91                 .mode           = 0644,
  92                 .proc_handler   = &proc_dointvec,
  93         },
  94         {
  95                 .ctl_name       = NET_NF_CONNTRACK_FRAG6_HIGH_THRESH,
  96                 .procname       = "nf_conntrack_frag6_high_thresh",
  97                 .data           = &nf_init_frags.high_thresh,
  98                 .maxlen         = sizeof(unsigned int),
  99                 .mode           = 0644,
 100                 .proc_handler   = &proc_dointvec,
 101         },
 102         { .ctl_name = 0 }
 103 };
 104 #endif
 105
 106 static unsigned int ip6qhashfn(__be32 id, struct in6_addr *saddr,
 107                                struct in6_addr *daddr)
 108 {
 109         u32 a, b, c;
 110
 111         a = (__force u32)saddr->s6_addr32[0];
 112         b = (__force u32)saddr->s6_addr32[1];
 113         c = (__force u32)saddr->s6_addr32[2];
 114
 115         a += JHASH_GOLDEN_RATIO;
 116         b += JHASH_GOLDEN_RATIO;
 117         c += nf_frags.rnd;
 118         __jhash_mix(a, b, c);
 119
 120         a += (__force u32)saddr->s6_addr32[3];
 121         b += (__force u32)daddr->s6_addr32[0];
 122         c += (__force u32)daddr->s6_addr32[1];
 123         __jhash_mix(a, b, c);
 124
 125         a += (__force u32)daddr->s6_addr32[2];
 126         b += (__force u32)daddr->s6_addr32[3];
 127         c += (__force u32)id;
 128         __jhash_mix(a, b, c);
 129
 130         return c & (INETFRAGS_HASHSZ - 1);
 131 }
 132
 133 static unsigned int nf_hashfn(struct inet_frag_queue *q)
 134 {
 135         struct nf_ct_frag6_queue *nq;
 136
 137         nq = container_of(q, struct nf_ct_frag6_queue, q);
 138         return ip6qhashfn(nq->id, &nq->saddr, &nq->daddr);
 139 }
 140
 141 static void nf_skb_free(struct sk_buff *skb)
 142 {
 143         if (NFCT_FRAG6_CB(skb)->orig)
 144                 kfree_skb(NFCT_FRAG6_CB(skb)->orig);
 145 }
 146
 147 /* Memory Tracking Functions. */
 148 static inline void frag_kfree_skb(struct sk_buff *skb, unsigned int *work)
 149 {
 150         if (work)
 151                 *work -= skb->truesize;
 152         atomic_sub(skb->truesize, &nf_init_frags.mem);
 153         nf_skb_free(skb);
 154         kfree_skb(skb);
 155 }
 156
 157 /* Destruction primitives. */
 158
 159 static __inline__ void fq_put(struct nf_ct_frag6_queue *fq)
 160 {
 161         inet_frag_put(&fq->q, &nf_frags);
 162 }
 163
 164 /* Kill fq entry. It is not destroyed immediately,
 165  * because caller (and someone more) holds reference count.
 166  */
 167 static __inline__ void fq_kill(struct nf_ct_frag6_queue *fq)
 168 {
 169         inet_frag_kill(&fq->q, &nf_frags);
 170 }
 171
 172 static void nf_ct_frag6_evictor(void)
 173 {
 174         local_bh_disable();
 175         inet_frag_evictor(&nf_init_frags, &nf_frags);
 176         local_bh_enable();
 177 }
 178
 179 static void nf_ct_frag6_expire(unsigned long data)
 180 {
 181         struct nf_ct_frag6_queue *fq;
 182
 183         fq = container_of((struct inet_frag_queue *)data,
 184                         struct nf_ct_frag6_queue, q);
 185
 186         spin_lock(&fq->q.lock);
 187
 188         if (fq->q.last_in & INET_FRAG_COMPLETE)
 189                 goto out;
 190
 191         fq_kill(fq);
 192
 193 out:
 194         spin_unlock(&fq->q.lock);
 195         fq_put(fq);
 196 }
 197
 198 /* Creation primitives. */
 199
 200 static __inline__ struct nf_ct_frag6_queue *
 201 fq_find(__be32 id, struct in6_addr *src, struct in6_addr *dst)
 202 {
 203         struct inet_frag_queue *q;
 204         struct ip6_create_arg arg;
 205         unsigned int hash;
 206
 207         arg.id = id;
 208         arg.src = src;
 209         arg.dst = dst;
 210         hash = ip6qhashfn(id, src, dst);
 211
 212         q = inet_frag_find(&nf_init_frags, &nf_frags, &arg, hash);
 213         if (q == NULL)
 214                 goto oom;
 215
 216         return container_of(q, struct nf_ct_frag6_queue, q);
 217
 218 oom:
 219         pr_debug("Can't alloc new queue\n");
 220         return NULL;
 221 }
 222
 223
 224 static int nf_ct_frag6_queue(struct nf_ct_frag6_queue *fq, struct sk_buff *skb,
 225                              struct frag_hdr *fhdr, int nhoff)
 226 {
 227         struct sk_buff *prev, *next;
 228         int offset, end;
 229
 230         if (fq->q.last_in & INET_FRAG_COMPLETE) {
 231                 pr_debug("Allready completed\n");
 232                 goto err;
 233         }
 234
 235         offset = ntohs(fhdr->frag_off) & ~0x7;
 236         end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
 237                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
 238
 239         if ((unsigned int)end > IPV6_MAXPLEN) {
 240                 pr_debug("offset is too large.\n");
 241                 return -1;
 242         }
 243
 244         if (skb->ip_summed == CHECKSUM_COMPLETE) {
 245                 const unsigned char *nh = skb_network_header(skb);
 246                 skb->csum = csum_sub(skb->csum,
 247                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
 248                                                   0));
 249         }
 250
 251         /* Is this the final fragment? */
 252         if (!(fhdr->frag_off & htons(IP6_MF))) {
 253                 /* If we already have some bits beyond end
 254                  * or have different end, the segment is corrupted.
 255                  */
 256                 if (end < fq->q.len ||
 257                     ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len)) {
 258                         pr_debug("already received last fragment\n");
 259                         goto err;
 260                 }
 261                 fq->q.last_in |= INET_FRAG_LAST_IN;
 262                 fq->q.len = end;
 263         } else {
 264                 /* Check if the fragment is rounded to 8 bytes.
 265                  * Required by the RFC.
 266                  */
 267                 if (end & 0x7) {
 268                         /* RFC2460 says always send parameter problem in
 269                          * this case. -DaveM
 270                          */
 271                         pr_debug("end of fragment not rounded to 8 bytes.\n");
 272                         return -1;
 273                 }
 274                 if (end > fq->q.len) {
 275                         /* Some bits beyond end -> corruption. */
 276                         if (fq->q.last_in & INET_FRAG_LAST_IN) {
 277                                 pr_debug("last packet already reached.\n");
 278                                 goto err;
 279                         }
 280                         fq->q.len = end;
 281                 }
 282         }
 283
 284         if (end == offset)
 285                 goto err;
 286
 287         /* Point into the IP datagram 'data' part. */
 288         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) {
 289                 pr_debug("queue: message is too short.\n");
 290                 goto err;
 291         }
 292         if (pskb_trim_rcsum(skb, end - offset)) {
 293                 pr_debug("Can't trim\n");
 294                 goto err;
 295         }
 296
 297         /* Find out which fragments are in front and at the back of us
 298          * in the chain of fragments so far.  We must know where to put
 299          * this fragment, right?
 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         /* We found where to put this one.  Check for overlap with
 309          * preceding fragment, and, if needed, align things so that
 310          * any overlaps are eliminated.
 311          */
 312         if (prev) {
 313                 int i = (NFCT_FRAG6_CB(prev)->offset + prev->len) - offset;
 314
 315                 if (i > 0) {
 316                         offset += i;
 317                         if (end <= offset) {
 318                                 pr_debug("overlap\n");
 319                                 goto err;
 320                         }
 321                         if (!pskb_pull(skb, i)) {
 322                                 pr_debug("Can't pull\n");
 323                                 goto err;
 324                         }
 325                         if (skb->ip_summed != CHECKSUM_UNNECESSARY)
 326                                 skb->ip_summed = CHECKSUM_NONE;
 327                 }
 328         }
 329
 330         /* Look for overlap with succeeding segments.
 331          * If we can merge fragments, do it.
 332          */
 333         while (next && NFCT_FRAG6_CB(next)->offset < end) {
 334                 /* overlap is 'i' bytes */
 335                 int i = end - NFCT_FRAG6_CB(next)->offset;
 336
 337                 if (i < next->len) {
 338                         /* Eat head of the next overlapped fragment
 339                          * and leave the loop. The next ones cannot overlap.
 340                          */
 341                         pr_debug("Eat head of the overlapped parts.: %d", i);
 342                         if (!pskb_pull(next, i))
 343                                 goto err;
 344
 345                         /* next fragment */
 346                         NFCT_FRAG6_CB(next)->offset += i;
 347                         fq->q.meat -= i;
 348                         if (next->ip_summed != CHECKSUM_UNNECESSARY)
 349                                 next->ip_summed = CHECKSUM_NONE;
 350                         break;
 351                 } else {
 352                         struct sk_buff *free_it = next;
 353
 354                         /* Old fragmnet is completely overridden with
 355                          * new one drop it.
 356                          */
 357                         next = next->next;
 358
 359                         if (prev)
 360                                 prev->next = next;
 361                         else
 362                                 fq->q.fragments = next;
 363
 364                         fq->q.meat -= free_it->len;
 365                         frag_kfree_skb(free_it, NULL);
 366                 }
 367         }
 368
 369         NFCT_FRAG6_CB(skb)->offset = offset;
 370
 371         /* Insert this fragment in the chain of fragments. */
 372         skb->next = next;
 373         if (prev)
 374                 prev->next = skb;
 375         else
 376                 fq->q.fragments = skb;
 377
 378         skb->dev = NULL;
 379         fq->q.stamp = skb->tstamp;
 380         fq->q.meat += skb->len;
 381         atomic_add(skb->truesize, &nf_init_frags.mem);
 382
 383         /* The first fragment.
 384          * nhoffset is obtained from the first fragment, of course.
 385          */
 386         if (offset == 0) {
 387                 fq->nhoffset = nhoff;
 388                 fq->q.last_in |= INET_FRAG_FIRST_IN;
 389         }
 390         write_lock(&nf_frags.lock);
 391         list_move_tail(&fq->q.lru_list, &nf_init_frags.lru_list);
 392         write_unlock(&nf_frags.lock);
 393         return 0;
 394
 395 err:
 396         return -1;
 397 }
 398
 399 /*
 400  *      Check if this packet is complete.
 401  *      Returns NULL on failure by any reason, and pointer
 402  *      to current nexthdr field in reassembled frame.
 403  *
 404  *      It is called with locked fq, and caller must check that
 405  *      queue is eligible for reassembly i.e. it is not COMPLETE,
 406  *      the last and the first frames arrived and all the bits are here.
 407  */
 408 static struct sk_buff *
 409 nf_ct_frag6_reasm(struct nf_ct_frag6_queue *fq, struct net_device *dev)
 410 {
 411         struct sk_buff *fp, *op, *head = fq->q.fragments;
 412         int    payload_len;
 413
 414         fq_kill(fq);
 415
 416         BUG_TRAP(head != NULL);
 417         BUG_TRAP(NFCT_FRAG6_CB(head)->offset == 0);
 418
 419         /* Unfragmented part is taken from the first segment. */
 420         payload_len = ((head->data - skb_network_header(head)) -
 421                        sizeof(struct ipv6hdr) + fq->q.len -
 422                        sizeof(struct frag_hdr));
 423         if (payload_len > IPV6_MAXPLEN) {
 424                 pr_debug("payload len is too large.\n");
 425                 goto out_oversize;
 426         }
 427
 428         /* Head of list must not be cloned. */
 429         if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) {
 430                 pr_debug("skb is cloned but can't expand head");
 431                 goto out_oom;
 432         }
 433
 434         /* If the first fragment is fragmented itself, we split
 435          * it to two chunks: the first with data and paged part
 436          * and the second, holding only fragments. */
 437         if (skb_shinfo(head)->frag_list) {
 438                 struct sk_buff *clone;
 439                 int i, plen = 0;
 440
 441                 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) {
 442                         pr_debug("Can't alloc skb\n");
 443                         goto out_oom;
 444                 }
 445                 clone->next = head->next;
 446                 head->next = clone;
 447                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
 448                 skb_shinfo(head)->frag_list = NULL;
 449                 for (i=0; i<skb_shinfo(head)->nr_frags; i++)
 450                         plen += skb_shinfo(head)->frags[i].size;
 451                 clone->len = clone->data_len = head->data_len - plen;
 452                 head->data_len -= clone->len;
 453                 head->len -= clone->len;
 454                 clone->csum = 0;
 455                 clone->ip_summed = head->ip_summed;
 456
 457                 NFCT_FRAG6_CB(clone)->orig = NULL;
 458                 atomic_add(clone->truesize, &nf_init_frags.mem);
 459         }
 460
 461         /* We have to remove fragment header from datagram and to relocate
 462          * header in order to calculate ICV correctly. */
 463         skb_network_header(head)[fq->nhoffset] = skb_transport_header(head)[0];
 464         memmove(head->head + sizeof(struct frag_hdr), head->head,
 465                 (head->data - head->head) - sizeof(struct frag_hdr));
 466         head->mac_header += sizeof(struct frag_hdr);
 467         head->network_header += sizeof(struct frag_hdr);
 468
 469         skb_shinfo(head)->frag_list = head->next;
 470         skb_reset_transport_header(head);
 471         skb_push(head, head->data - skb_network_header(head));
 472         atomic_sub(head->truesize, &nf_init_frags.mem);
 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                 atomic_sub(fp->truesize, &nf_init_frags.mem);
 483         }
 484
 485         head->next = NULL;
 486         head->dev = dev;
 487         head->tstamp = fq->q.stamp;
 488         ipv6_hdr(head)->payload_len = htons(payload_len);
 489
 490         /* Yes, and fold redundant checksum back. 8) */
 491         if (head->ip_summed == CHECKSUM_COMPLETE)
 492                 head->csum = csum_partial(skb_network_header(head),
 493                                           skb_network_header_len(head),
 494                                           head->csum);
 495
 496         fq->q.fragments = NULL;
 497
 498         /* all original skbs are linked into the NFCT_FRAG6_CB(head).orig */
 499         fp = skb_shinfo(head)->frag_list;
 500         if (NFCT_FRAG6_CB(fp)->orig == NULL)
 501                 /* at above code, head skb is divided into two skbs. */
 502                 fp = fp->next;
 503
 504         op = NFCT_FRAG6_CB(head)->orig;
 505         for (; fp; fp = fp->next) {
 506                 struct sk_buff *orig = NFCT_FRAG6_CB(fp)->orig;
 507
 508                 op->next = orig;
 509                 op = orig;
 510                 NFCT_FRAG6_CB(fp)->orig = NULL;
 511         }
 512
 513         return head;
 514
 515 out_oversize:
 516         if (net_ratelimit())
 517                 printk(KERN_DEBUG "nf_ct_frag6_reasm: payload len = %d\n", payload_len);
 518         goto out_fail;
 519 out_oom:
 520         if (net_ratelimit())
 521                 printk(KERN_DEBUG "nf_ct_frag6_reasm: no memory for reassembly\n");
 522 out_fail:
 523         return NULL;
 524 }
 525
 526 /*
 527  * find the header just before Fragment Header.
 528  *
 529  * if success return 0 and set ...
 530  * (*prevhdrp): the value of "Next Header Field" in the header
 531  *              just before Fragment Header.
 532  * (*prevhoff): the offset of "Next Header Field" in the header
 533  *              just before Fragment Header.
 534  * (*fhoff)   : the offset of Fragment Header.
 535  *
 536  * Based on ipv6_skip_hdr() in net/ipv6/exthdr.c
 537  *
 538  */
 539 static int
 540 find_prev_fhdr(struct sk_buff *skb, u8 *prevhdrp, int *prevhoff, int *fhoff)
 541 {
 542         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 543         const int netoff = skb_network_offset(skb);
 544         u8 prev_nhoff = netoff + offsetof(struct ipv6hdr, nexthdr);
 545         int start = netoff + sizeof(struct ipv6hdr);
 546         int len = skb->len - start;
 547         u8 prevhdr = NEXTHDR_IPV6;
 548
 549         while (nexthdr != NEXTHDR_FRAGMENT) {
 550                 struct ipv6_opt_hdr hdr;
 551                 int hdrlen;
 552
 553                 if (!ipv6_ext_hdr(nexthdr)) {
 554                         return -1;
 555                 }
 556                 if (len < (int)sizeof(struct ipv6_opt_hdr)) {
 557                         pr_debug("too short\n");
 558                         return -1;
 559                 }
 560                 if (nexthdr == NEXTHDR_NONE) {
 561                         pr_debug("next header is none\n");
 562                         return -1;
 563                 }
 564                 if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
 565                         BUG();
 566                 if (nexthdr == NEXTHDR_AUTH)
 567                         hdrlen = (hdr.hdrlen+2)<<2;
 568                 else
 569                         hdrlen = ipv6_optlen(&hdr);
 570
 571                 prevhdr = nexthdr;
 572                 prev_nhoff = start;
 573
 574                 nexthdr = hdr.nexthdr;
 575                 len -= hdrlen;
 576                 start += hdrlen;
 577         }
 578
 579         if (len < 0)
 580                 return -1;
 581
 582         *prevhdrp = prevhdr;
 583         *prevhoff = prev_nhoff;
 584         *fhoff = start;
 585
 586         return 0;
 587 }
 588
 589 struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb)
 590 {
 591         struct sk_buff *clone;
 592         struct net_device *dev = skb->dev;
 593         struct frag_hdr *fhdr;
 594         struct nf_ct_frag6_queue *fq;
 595         struct ipv6hdr *hdr;
 596         int fhoff, nhoff;
 597         u8 prevhdr;
 598         struct sk_buff *ret_skb = NULL;
 599
 600         /* Jumbo payload inhibits frag. header */
 601         if (ipv6_hdr(skb)->payload_len == 0) {
 602                 pr_debug("payload len = 0\n");
 603                 return skb;
 604         }
 605
 606         if (find_prev_fhdr(skb, &prevhdr, &nhoff, &fhoff) < 0)
 607                 return skb;
 608
 609         clone = skb_clone(skb, GFP_ATOMIC);
 610         if (clone == NULL) {
 611                 pr_debug("Can't clone skb\n");
 612                 return skb;
 613         }
 614
 615         NFCT_FRAG6_CB(clone)->orig = skb;
 616
 617         if (!pskb_may_pull(clone, fhoff + sizeof(*fhdr))) {
 618                 pr_debug("message is too short.\n");
 619                 goto ret_orig;
 620         }
 621
 622         skb_set_transport_header(clone, fhoff);
 623         hdr = ipv6_hdr(clone);
 624         fhdr = (struct frag_hdr *)skb_transport_header(clone);
 625
 626         if (!(fhdr->frag_off & htons(0xFFF9))) {
 627                 pr_debug("Invalid fragment offset\n");
 628                 /* It is not a fragmented frame */
 629                 goto ret_orig;
 630         }
 631
 632         if (atomic_read(&nf_init_frags.mem) > nf_init_frags.high_thresh)
 633                 nf_ct_frag6_evictor();
 634
 635         fq = fq_find(fhdr->identification, &hdr->saddr, &hdr->daddr);
 636         if (fq == NULL) {
 637                 pr_debug("Can't find and can't create new queue\n");
 638                 goto ret_orig;
 639         }
 640
 641         spin_lock(&fq->q.lock);
 642
 643         if (nf_ct_frag6_queue(fq, clone, fhdr, nhoff) < 0) {
 644                 spin_unlock(&fq->q.lock);
 645                 pr_debug("Can't insert skb to queue\n");
 646                 fq_put(fq);
 647                 goto ret_orig;
 648         }
 649
 650         if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
 651             fq->q.meat == fq->q.len) {
 652                 ret_skb = nf_ct_frag6_reasm(fq, dev);
 653                 if (ret_skb == NULL)
 654                         pr_debug("Can't reassemble fragmented packets\n");
 655         }
 656         spin_unlock(&fq->q.lock);
 657
 658         fq_put(fq);
 659         return ret_skb;
 660
 661 ret_orig:
 662         kfree_skb(clone);
 663         return skb;
 664 }
 665
 666 void nf_ct_frag6_output(unsigned int hooknum, struct sk_buff *skb,
 667                         struct net_device *in, struct net_device *out,
 668                         int (*okfn)(struct sk_buff *))
 669 {
 670         struct sk_buff *s, *s2;
 671
 672         for (s = NFCT_FRAG6_CB(skb)->orig; s;) {
 673                 nf_conntrack_put_reasm(s->nfct_reasm);
 674                 nf_conntrack_get_reasm(skb);
 675                 s->nfct_reasm = skb;
 676
 677                 s2 = s->next;
 678                 s->next = NULL;
 679
 680                 NF_HOOK_THRESH(PF_INET6, hooknum, s, in, out, okfn,
 681                                NF_IP6_PRI_CONNTRACK_DEFRAG + 1);
 682                 s = s2;
 683         }
 684         nf_conntrack_put_reasm(skb);
 685 }
 686
 687 int nf_ct_frag6_init(void)
 688 {
 689         nf_frags.hashfn = nf_hashfn;
 690         nf_frags.constructor = ip6_frag_init;
 691         nf_frags.destructor = NULL;
 692         nf_frags.skb_free = nf_skb_free;
 693         nf_frags.qsize = sizeof(struct nf_ct_frag6_queue);
 694         nf_frags.match = ip6_frag_match;
 695         nf_frags.frag_expire = nf_ct_frag6_expire;
 696         nf_frags.secret_interval = 10 * 60 * HZ;
 697         nf_init_frags.timeout = IPV6_FRAG_TIMEOUT;
 698         nf_init_frags.high_thresh = 256 * 1024;
 699         nf_init_frags.low_thresh = 192 * 1024;
 700         inet_frags_init_net(&nf_init_frags);
 701         inet_frags_init(&nf_frags);
 702
 703         return 0;
 704 }
 705
 706 void nf_ct_frag6_cleanup(void)
 707 {
 708         inet_frags_fini(&nf_frags);
 709
 710         nf_init_frags.low_thresh = 0;
 711         nf_ct_frag6_evictor();
 712 }