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 static 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 static struct netns_frags nf_init_frags;
  82
  83 #ifdef CONFIG_SYSCTL
  84 struct ctl_table nf_ct_ipv6_sysctl_table[] = {
  85         {
  86                 .procname       = "nf_conntrack_frag6_timeout",
  87                 .data           = &nf_frags_ctl.timeout,
  88                 .maxlen         = sizeof(unsigned int),
  89                 .mode           = 0644,
  90                 .proc_handler   = &proc_dointvec_jiffies,
  91         },
  92         {
  93                 .ctl_name       = NET_NF_CONNTRACK_FRAG6_LOW_THRESH,
  94                 .procname       = "nf_conntrack_frag6_low_thresh",
  95                 .data           = &nf_frags_ctl.low_thresh,
  96                 .maxlen         = sizeof(unsigned int),
  97                 .mode           = 0644,
  98                 .proc_handler   = &proc_dointvec,
  99         },
 100         {
 101                 .ctl_name       = NET_NF_CONNTRACK_FRAG6_HIGH_THRESH,
 102                 .procname       = "nf_conntrack_frag6_high_thresh",
 103                 .data           = &nf_frags_ctl.high_thresh,
 104                 .maxlen         = sizeof(unsigned int),
 105                 .mode           = 0644,
 106                 .proc_handler   = &proc_dointvec,
 107         },
 108         { .ctl_name = 0 }
 109 };
 110 #endif
 111
 112 static unsigned int ip6qhashfn(__be32 id, struct in6_addr *saddr,
 113                                struct in6_addr *daddr)
 114 {
 115         u32 a, b, c;
 116
 117         a = (__force u32)saddr->s6_addr32[0];
 118         b = (__force u32)saddr->s6_addr32[1];
 119         c = (__force u32)saddr->s6_addr32[2];
 120
 121         a += JHASH_GOLDEN_RATIO;
 122         b += JHASH_GOLDEN_RATIO;
 123         c += nf_frags.rnd;
 124         __jhash_mix(a, b, c);
 125
 126         a += (__force u32)saddr->s6_addr32[3];
 127         b += (__force u32)daddr->s6_addr32[0];
 128         c += (__force u32)daddr->s6_addr32[1];
 129         __jhash_mix(a, b, c);
 130
 131         a += (__force u32)daddr->s6_addr32[2];
 132         b += (__force u32)daddr->s6_addr32[3];
 133         c += (__force u32)id;
 134         __jhash_mix(a, b, c);
 135
 136         return c & (INETFRAGS_HASHSZ - 1);
 137 }
 138
 139 static unsigned int nf_hashfn(struct inet_frag_queue *q)
 140 {
 141         struct nf_ct_frag6_queue *nq;
 142
 143         nq = container_of(q, struct nf_ct_frag6_queue, q);
 144         return ip6qhashfn(nq->id, &nq->saddr, &nq->daddr);
 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 /* Memory Tracking Functions. */
 154 static inline void frag_kfree_skb(struct sk_buff *skb, unsigned int *work)
 155 {
 156         if (work)
 157                 *work -= skb->truesize;
 158         atomic_sub(skb->truesize, &nf_frags.mem);
 159         nf_skb_free(skb);
 160         kfree_skb(skb);
 161 }
 162
 163 /* Destruction primitives. */
 164
 165 static __inline__ void fq_put(struct nf_ct_frag6_queue *fq)
 166 {
 167         inet_frag_put(&fq->q, &nf_frags);
 168 }
 169
 170 /* Kill fq entry. It is not destroyed immediately,
 171  * because caller (and someone more) holds reference count.
 172  */
 173 static __inline__ void fq_kill(struct nf_ct_frag6_queue *fq)
 174 {
 175         inet_frag_kill(&fq->q, &nf_frags);
 176 }
 177
 178 static void nf_ct_frag6_evictor(void)
 179 {
 180         inet_frag_evictor(&nf_frags);
 181 }
 182
 183 static void nf_ct_frag6_expire(unsigned long data)
 184 {
 185         struct nf_ct_frag6_queue *fq;
 186
 187         fq = container_of((struct inet_frag_queue *)data,
 188                         struct nf_ct_frag6_queue, q);
 189
 190         spin_lock(&fq->q.lock);
 191
 192         if (fq->q.last_in & COMPLETE)
 193                 goto out;
 194
 195         fq_kill(fq);
 196
 197 out:
 198         spin_unlock(&fq->q.lock);
 199         fq_put(fq);
 200 }
 201
 202 /* Creation primitives. */
 203
 204 static __inline__ struct nf_ct_frag6_queue *
 205 fq_find(__be32 id, struct in6_addr *src, struct in6_addr *dst)
 206 {
 207         struct inet_frag_queue *q;
 208         struct ip6_create_arg arg;
 209         unsigned int hash;
 210
 211         arg.id = id;
 212         arg.src = src;
 213         arg.dst = dst;
 214         hash = ip6qhashfn(id, src, dst);
 215
 216         q = inet_frag_find(&nf_init_frags, &nf_frags, &arg, hash);
 217         if (q == NULL)
 218                 goto oom;
 219
 220         return container_of(q, struct nf_ct_frag6_queue, q);
 221
 222 oom:
 223         pr_debug("Can't alloc new queue\n");
 224         return NULL;
 225 }
 226
 227
 228 static int nf_ct_frag6_queue(struct nf_ct_frag6_queue *fq, struct sk_buff *skb,
 229                              struct frag_hdr *fhdr, int nhoff)
 230 {
 231         struct sk_buff *prev, *next;
 232         int offset, end;
 233
 234         if (fq->q.last_in & COMPLETE) {
 235                 pr_debug("Allready completed\n");
 236                 goto err;
 237         }
 238
 239         offset = ntohs(fhdr->frag_off) & ~0x7;
 240         end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
 241                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
 242
 243         if ((unsigned int)end > IPV6_MAXPLEN) {
 244                 pr_debug("offset is too large.\n");
 245                 return -1;
 246         }
 247
 248         if (skb->ip_summed == CHECKSUM_COMPLETE) {
 249                 const unsigned char *nh = skb_network_header(skb);
 250                 skb->csum = csum_sub(skb->csum,
 251                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
 252                                                   0));
 253         }
 254
 255         /* Is this the final fragment? */
 256         if (!(fhdr->frag_off & htons(IP6_MF))) {
 257                 /* If we already have some bits beyond end
 258                  * or have different end, the segment is corrupted.
 259                  */
 260                 if (end < fq->q.len ||
 261                     ((fq->q.last_in & LAST_IN) && end != fq->q.len)) {
 262                         pr_debug("already received last fragment\n");
 263                         goto err;
 264                 }
 265                 fq->q.last_in |= LAST_IN;
 266                 fq->q.len = end;
 267         } else {
 268                 /* Check if the fragment is rounded to 8 bytes.
 269                  * Required by the RFC.
 270                  */
 271                 if (end & 0x7) {
 272                         /* RFC2460 says always send parameter problem in
 273                          * this case. -DaveM
 274                          */
 275                         pr_debug("end of fragment not rounded to 8 bytes.\n");
 276                         return -1;
 277                 }
 278                 if (end > fq->q.len) {
 279                         /* Some bits beyond end -> corruption. */
 280                         if (fq->q.last_in & LAST_IN) {
 281                                 pr_debug("last packet already reached.\n");
 282                                 goto err;
 283                         }
 284                         fq->q.len = end;
 285                 }
 286         }
 287
 288         if (end == offset)
 289                 goto err;
 290
 291         /* Point into the IP datagram 'data' part. */
 292         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) {
 293                 pr_debug("queue: message is too short.\n");
 294                 goto err;
 295         }
 296         if (pskb_trim_rcsum(skb, end - offset)) {
 297                 pr_debug("Can't trim\n");
 298                 goto err;
 299         }
 300
 301         /* Find out which fragments are in front and at the back of us
 302          * in the chain of fragments so far.  We must know where to put
 303          * this fragment, right?
 304          */
 305         prev = NULL;
 306         for (next = fq->q.fragments; next != NULL; next = next->next) {
 307                 if (NFCT_FRAG6_CB(next)->offset >= offset)
 308                         break;  /* bingo! */
 309                 prev = next;
 310         }
 311
 312         /* We found where to put this one.  Check for overlap with
 313          * preceding fragment, and, if needed, align things so that
 314          * any overlaps are eliminated.
 315          */
 316         if (prev) {
 317                 int i = (NFCT_FRAG6_CB(prev)->offset + prev->len) - offset;
 318
 319                 if (i > 0) {
 320                         offset += i;
 321                         if (end <= offset) {
 322                                 pr_debug("overlap\n");
 323                                 goto err;
 324                         }
 325                         if (!pskb_pull(skb, i)) {
 326                                 pr_debug("Can't pull\n");
 327                                 goto err;
 328                         }
 329                         if (skb->ip_summed != CHECKSUM_UNNECESSARY)
 330                                 skb->ip_summed = CHECKSUM_NONE;
 331                 }
 332         }
 333
 334         /* Look for overlap with succeeding segments.
 335          * If we can merge fragments, do it.
 336          */
 337         while (next && NFCT_FRAG6_CB(next)->offset < end) {
 338                 /* overlap is 'i' bytes */
 339                 int i = end - NFCT_FRAG6_CB(next)->offset;
 340
 341                 if (i < next->len) {
 342                         /* Eat head of the next overlapped fragment
 343                          * and leave the loop. The next ones cannot overlap.
 344                          */
 345                         pr_debug("Eat head of the overlapped parts.: %d", i);
 346                         if (!pskb_pull(next, i))
 347                                 goto err;
 348
 349                         /* next fragment */
 350                         NFCT_FRAG6_CB(next)->offset += i;
 351                         fq->q.meat -= i;
 352                         if (next->ip_summed != CHECKSUM_UNNECESSARY)
 353                                 next->ip_summed = CHECKSUM_NONE;
 354                         break;
 355                 } else {
 356                         struct sk_buff *free_it = next;
 357
 358                         /* Old fragmnet is completely overridden with
 359                          * new one drop it.
 360                          */
 361                         next = next->next;
 362
 363                         if (prev)
 364                                 prev->next = next;
 365                         else
 366                                 fq->q.fragments = next;
 367
 368                         fq->q.meat -= free_it->len;
 369                         frag_kfree_skb(free_it, NULL);
 370                 }
 371         }
 372
 373         NFCT_FRAG6_CB(skb)->offset = offset;
 374
 375         /* Insert this fragment in the chain of fragments. */
 376         skb->next = next;
 377         if (prev)
 378                 prev->next = skb;
 379         else
 380                 fq->q.fragments = skb;
 381
 382         skb->dev = NULL;
 383         fq->q.stamp = skb->tstamp;
 384         fq->q.meat += skb->len;
 385         atomic_add(skb->truesize, &nf_frags.mem);
 386
 387         /* The first fragment.
 388          * nhoffset is obtained from the first fragment, of course.
 389          */
 390         if (offset == 0) {
 391                 fq->nhoffset = nhoff;
 392                 fq->q.last_in |= FIRST_IN;
 393         }
 394         write_lock(&nf_frags.lock);
 395         list_move_tail(&fq->q.lru_list, &nf_frags.lru_list);
 396         write_unlock(&nf_frags.lock);
 397         return 0;
 398
 399 err:
 400         return -1;
 401 }
 402
 403 /*
 404  *      Check if this packet is complete.
 405  *      Returns NULL on failure by any reason, and pointer
 406  *      to current nexthdr field in reassembled frame.
 407  *
 408  *      It is called with locked fq, and caller must check that
 409  *      queue is eligible for reassembly i.e. it is not COMPLETE,
 410  *      the last and the first frames arrived and all the bits are here.
 411  */
 412 static struct sk_buff *
 413 nf_ct_frag6_reasm(struct nf_ct_frag6_queue *fq, struct net_device *dev)
 414 {
 415         struct sk_buff *fp, *op, *head = fq->q.fragments;
 416         int    payload_len;
 417
 418         fq_kill(fq);
 419
 420         BUG_TRAP(head != NULL);
 421         BUG_TRAP(NFCT_FRAG6_CB(head)->offset == 0);
 422
 423         /* Unfragmented part is taken from the first segment. */
 424         payload_len = ((head->data - skb_network_header(head)) -
 425                        sizeof(struct ipv6hdr) + fq->q.len -
 426                        sizeof(struct frag_hdr));
 427         if (payload_len > IPV6_MAXPLEN) {
 428                 pr_debug("payload len is too large.\n");
 429                 goto out_oversize;
 430         }
 431
 432         /* Head of list must not be cloned. */
 433         if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) {
 434                 pr_debug("skb is cloned but can't expand head");
 435                 goto out_oom;
 436         }
 437
 438         /* If the first fragment is fragmented itself, we split
 439          * it to two chunks: the first with data and paged part
 440          * and the second, holding only fragments. */
 441         if (skb_shinfo(head)->frag_list) {
 442                 struct sk_buff *clone;
 443                 int i, plen = 0;
 444
 445                 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) {
 446                         pr_debug("Can't alloc skb\n");
 447                         goto out_oom;
 448                 }
 449                 clone->next = head->next;
 450                 head->next = clone;
 451                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
 452                 skb_shinfo(head)->frag_list = NULL;
 453                 for (i=0; i<skb_shinfo(head)->nr_frags; i++)
 454                         plen += skb_shinfo(head)->frags[i].size;
 455                 clone->len = clone->data_len = head->data_len - plen;
 456                 head->data_len -= clone->len;
 457                 head->len -= clone->len;
 458                 clone->csum = 0;
 459                 clone->ip_summed = head->ip_summed;
 460
 461                 NFCT_FRAG6_CB(clone)->orig = NULL;
 462                 atomic_add(clone->truesize, &nf_frags.mem);
 463         }
 464
 465         /* We have to remove fragment header from datagram and to relocate
 466          * header in order to calculate ICV correctly. */
 467         skb_network_header(head)[fq->nhoffset] = skb_transport_header(head)[0];
 468         memmove(head->head + sizeof(struct frag_hdr), head->head,
 469                 (head->data - head->head) - sizeof(struct frag_hdr));
 470         head->mac_header += sizeof(struct frag_hdr);
 471         head->network_header += sizeof(struct frag_hdr);
 472
 473         skb_shinfo(head)->frag_list = head->next;
 474         skb_reset_transport_header(head);
 475         skb_push(head, head->data - skb_network_header(head));
 476         atomic_sub(head->truesize, &nf_frags.mem);
 477
 478         for (fp=head->next; fp; fp = fp->next) {
 479                 head->data_len += fp->len;
 480                 head->len += fp->len;
 481                 if (head->ip_summed != fp->ip_summed)
 482                         head->ip_summed = CHECKSUM_NONE;
 483                 else if (head->ip_summed == CHECKSUM_COMPLETE)
 484                         head->csum = csum_add(head->csum, fp->csum);
 485                 head->truesize += fp->truesize;
 486                 atomic_sub(fp->truesize, &nf_frags.mem);
 487         }
 488
 489         head->next = NULL;
 490         head->dev = dev;
 491         head->tstamp = fq->q.stamp;
 492         ipv6_hdr(head)->payload_len = htons(payload_len);
 493
 494         /* Yes, and fold redundant checksum back. 8) */
 495         if (head->ip_summed == CHECKSUM_COMPLETE)
 496                 head->csum = csum_partial(skb_network_header(head),
 497                                           skb_network_header_len(head),
 498                                           head->csum);
 499
 500         fq->q.fragments = NULL;
 501
 502         /* all original skbs are linked into the NFCT_FRAG6_CB(head).orig */
 503         fp = skb_shinfo(head)->frag_list;
 504         if (NFCT_FRAG6_CB(fp)->orig == NULL)
 505                 /* at above code, head skb is divided into two skbs. */
 506                 fp = fp->next;
 507
 508         op = NFCT_FRAG6_CB(head)->orig;
 509         for (; fp; fp = fp->next) {
 510                 struct sk_buff *orig = NFCT_FRAG6_CB(fp)->orig;
 511
 512                 op->next = orig;
 513                 op = orig;
 514                 NFCT_FRAG6_CB(fp)->orig = NULL;
 515         }
 516
 517         return head;
 518
 519 out_oversize:
 520         if (net_ratelimit())
 521                 printk(KERN_DEBUG "nf_ct_frag6_reasm: payload len = %d\n", payload_len);
 522         goto out_fail;
 523 out_oom:
 524         if (net_ratelimit())
 525                 printk(KERN_DEBUG "nf_ct_frag6_reasm: no memory for reassembly\n");
 526 out_fail:
 527         return NULL;
 528 }
 529
 530 /*
 531  * find the header just before Fragment Header.
 532  *
 533  * if success return 0 and set ...
 534  * (*prevhdrp): the value of "Next Header Field" in the header
 535  *              just before Fragment Header.
 536  * (*prevhoff): the offset of "Next Header Field" in the header
 537  *              just before Fragment Header.
 538  * (*fhoff)   : the offset of Fragment Header.
 539  *
 540  * Based on ipv6_skip_hdr() in net/ipv6/exthdr.c
 541  *
 542  */
 543 static int
 544 find_prev_fhdr(struct sk_buff *skb, u8 *prevhdrp, int *prevhoff, int *fhoff)
 545 {
 546         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 547         const int netoff = skb_network_offset(skb);
 548         u8 prev_nhoff = netoff + offsetof(struct ipv6hdr, nexthdr);
 549         int start = netoff + sizeof(struct ipv6hdr);
 550         int len = skb->len - start;
 551         u8 prevhdr = NEXTHDR_IPV6;
 552
 553         while (nexthdr != NEXTHDR_FRAGMENT) {
 554                 struct ipv6_opt_hdr hdr;
 555                 int hdrlen;
 556
 557                 if (!ipv6_ext_hdr(nexthdr)) {
 558                         return -1;
 559                 }
 560                 if (len < (int)sizeof(struct ipv6_opt_hdr)) {
 561                         pr_debug("too short\n");
 562                         return -1;
 563                 }
 564                 if (nexthdr == NEXTHDR_NONE) {
 565                         pr_debug("next header is none\n");
 566                         return -1;
 567                 }
 568                 if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
 569                         BUG();
 570                 if (nexthdr == NEXTHDR_AUTH)
 571                         hdrlen = (hdr.hdrlen+2)<<2;
 572                 else
 573                         hdrlen = ipv6_optlen(&hdr);
 574
 575                 prevhdr = nexthdr;
 576                 prev_nhoff = start;
 577
 578                 nexthdr = hdr.nexthdr;
 579                 len -= hdrlen;
 580                 start += hdrlen;
 581         }
 582
 583         if (len < 0)
 584                 return -1;
 585
 586         *prevhdrp = prevhdr;
 587         *prevhoff = prev_nhoff;
 588         *fhoff = start;
 589
 590         return 0;
 591 }
 592
 593 struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb)
 594 {
 595         struct sk_buff *clone;
 596         struct net_device *dev = skb->dev;
 597         struct frag_hdr *fhdr;
 598         struct nf_ct_frag6_queue *fq;
 599         struct ipv6hdr *hdr;
 600         int fhoff, nhoff;
 601         u8 prevhdr;
 602         struct sk_buff *ret_skb = NULL;
 603
 604         /* Jumbo payload inhibits frag. header */
 605         if (ipv6_hdr(skb)->payload_len == 0) {
 606                 pr_debug("payload len = 0\n");
 607                 return skb;
 608         }
 609
 610         if (find_prev_fhdr(skb, &prevhdr, &nhoff, &fhoff) < 0)
 611                 return skb;
 612
 613         clone = skb_clone(skb, GFP_ATOMIC);
 614         if (clone == NULL) {
 615                 pr_debug("Can't clone skb\n");
 616                 return skb;
 617         }
 618
 619         NFCT_FRAG6_CB(clone)->orig = skb;
 620
 621         if (!pskb_may_pull(clone, fhoff + sizeof(*fhdr))) {
 622                 pr_debug("message is too short.\n");
 623                 goto ret_orig;
 624         }
 625
 626         skb_set_transport_header(clone, fhoff);
 627         hdr = ipv6_hdr(clone);
 628         fhdr = (struct frag_hdr *)skb_transport_header(clone);
 629
 630         if (!(fhdr->frag_off & htons(0xFFF9))) {
 631                 pr_debug("Invalid fragment offset\n");
 632                 /* It is not a fragmented frame */
 633                 goto ret_orig;
 634         }
 635
 636         if (atomic_read(&nf_frags.mem) > nf_frags_ctl.high_thresh)
 637                 nf_ct_frag6_evictor();
 638
 639         fq = fq_find(fhdr->identification, &hdr->saddr, &hdr->daddr);
 640         if (fq == NULL) {
 641                 pr_debug("Can't find and can't create new queue\n");
 642                 goto ret_orig;
 643         }
 644
 645         spin_lock(&fq->q.lock);
 646
 647         if (nf_ct_frag6_queue(fq, clone, fhdr, nhoff) < 0) {
 648                 spin_unlock(&fq->q.lock);
 649                 pr_debug("Can't insert skb to queue\n");
 650                 fq_put(fq);
 651                 goto ret_orig;
 652         }
 653
 654         if (fq->q.last_in == (FIRST_IN|LAST_IN) && fq->q.meat == fq->q.len) {
 655                 ret_skb = nf_ct_frag6_reasm(fq, dev);
 656                 if (ret_skb == NULL)
 657                         pr_debug("Can't reassemble fragmented packets\n");
 658         }
 659         spin_unlock(&fq->q.lock);
 660
 661         fq_put(fq);
 662         return ret_skb;
 663
 664 ret_orig:
 665         kfree_skb(clone);
 666         return skb;
 667 }
 668
 669 void nf_ct_frag6_output(unsigned int hooknum, struct sk_buff *skb,
 670                         struct net_device *in, struct net_device *out,
 671                         int (*okfn)(struct sk_buff *))
 672 {
 673         struct sk_buff *s, *s2;
 674
 675         for (s = NFCT_FRAG6_CB(skb)->orig; s;) {
 676                 nf_conntrack_put_reasm(s->nfct_reasm);
 677                 nf_conntrack_get_reasm(skb);
 678                 s->nfct_reasm = skb;
 679
 680                 s2 = s->next;
 681                 s->next = NULL;
 682
 683                 NF_HOOK_THRESH(PF_INET6, hooknum, s, in, out, okfn,
 684                                NF_IP6_PRI_CONNTRACK_DEFRAG + 1);
 685                 s = s2;
 686         }
 687         nf_conntrack_put_reasm(skb);
 688 }
 689
 690 int nf_ct_frag6_kfree_frags(struct sk_buff *skb)
 691 {
 692         struct sk_buff *s, *s2;
 693
 694         for (s = NFCT_FRAG6_CB(skb)->orig; s; s = s2) {
 695
 696                 s2 = s->next;
 697                 kfree_skb(s);
 698         }
 699
 700         kfree_skb(skb);
 701
 702         return 0;
 703 }
 704
 705 int nf_ct_frag6_init(void)
 706 {
 707         nf_frags.ctl = &nf_frags_ctl;
 708         nf_frags.hashfn = nf_hashfn;
 709         nf_frags.constructor = ip6_frag_init;
 710         nf_frags.destructor = NULL;
 711         nf_frags.skb_free = nf_skb_free;
 712         nf_frags.qsize = sizeof(struct nf_ct_frag6_queue);
 713         nf_frags.match = ip6_frag_match;
 714         nf_frags.frag_expire = nf_ct_frag6_expire;
 715         inet_frags_init_net(&nf_init_frags);
 716         inet_frags_init(&nf_frags);
 717
 718         return 0;
 719 }
 720
 721 void nf_ct_frag6_cleanup(void)
 722 {
 723         inet_frags_fini(&nf_frags);
 724
 725         nf_frags_ctl.low_thresh = 0;
 726         nf_ct_frag6_evictor();
 727 }