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 nf_frags;
  74 static struct netns_frags nf_init_frags;
  75
  76 #ifdef CONFIG_SYSCTL
  77 struct ctl_table nf_ct_ipv6_sysctl_table[] = {
  78         {
  79                 .procname       = "nf_conntrack_frag6_timeout",
  80                 .data           = &nf_init_frags.timeout,
  81                 .maxlen         = sizeof(unsigned int),
  82                 .mode           = 0644,
  83                 .proc_handler   = &proc_dointvec_jiffies,
  84         },
  85         {
  86                 .ctl_name       = NET_NF_CONNTRACK_FRAG6_LOW_THRESH,
  87                 .procname       = "nf_conntrack_frag6_low_thresh",
  88                 .data           = &nf_init_frags.low_thresh,
  89                 .maxlen         = sizeof(unsigned int),
  90                 .mode           = 0644,
  91                 .proc_handler   = &proc_dointvec,
  92         },
  93         {
  94                 .ctl_name       = NET_NF_CONNTRACK_FRAG6_HIGH_THRESH,
  95                 .procname       = "nf_conntrack_frag6_high_thresh",
  96                 .data           = &nf_init_frags.high_thresh,
  97                 .maxlen         = sizeof(unsigned int),
  98                 .mode           = 0644,
  99                 .proc_handler   = &proc_dointvec,
 100         },
 101         { .ctl_name = 0 }
 102 };
 103 #endif
 104
 105 static unsigned int ip6qhashfn(__be32 id, struct in6_addr *saddr,
 106                                struct in6_addr *daddr)
 107 {
 108         u32 a, b, c;
 109
 110         a = (__force u32)saddr->s6_addr32[0];
 111         b = (__force u32)saddr->s6_addr32[1];
 112         c = (__force u32)saddr->s6_addr32[2];
 113
 114         a += JHASH_GOLDEN_RATIO;
 115         b += JHASH_GOLDEN_RATIO;
 116         c += nf_frags.rnd;
 117         __jhash_mix(a, b, c);
 118
 119         a += (__force u32)saddr->s6_addr32[3];
 120         b += (__force u32)daddr->s6_addr32[0];
 121         c += (__force u32)daddr->s6_addr32[1];
 122         __jhash_mix(a, b, c);
 123
 124         a += (__force u32)daddr->s6_addr32[2];
 125         b += (__force u32)daddr->s6_addr32[3];
 126         c += (__force u32)id;
 127         __jhash_mix(a, b, c);
 128
 129         return c & (INETFRAGS_HASHSZ - 1);
 130 }
 131
 132 static unsigned int nf_hashfn(struct inet_frag_queue *q)
 133 {
 134         struct nf_ct_frag6_queue *nq;
 135
 136         nq = container_of(q, struct nf_ct_frag6_queue, q);
 137         return ip6qhashfn(nq->id, &nq->saddr, &nq->daddr);
 138 }
 139
 140 static void nf_skb_free(struct sk_buff *skb)
 141 {
 142         if (NFCT_FRAG6_CB(skb)->orig)
 143                 kfree_skb(NFCT_FRAG6_CB(skb)->orig);
 144 }
 145
 146 /* Memory Tracking Functions. */
 147 static inline void frag_kfree_skb(struct sk_buff *skb, unsigned int *work)
 148 {
 149         if (work)
 150                 *work -= skb->truesize;
 151         atomic_sub(skb->truesize, &nf_init_frags.mem);
 152         nf_skb_free(skb);
 153         kfree_skb(skb);
 154 }
 155
 156 /* Destruction primitives. */
 157
 158 static __inline__ void fq_put(struct nf_ct_frag6_queue *fq)
 159 {
 160         inet_frag_put(&fq->q, &nf_frags);
 161 }
 162
 163 /* Kill fq entry. It is not destroyed immediately,
 164  * because caller (and someone more) holds reference count.
 165  */
 166 static __inline__ void fq_kill(struct nf_ct_frag6_queue *fq)
 167 {
 168         inet_frag_kill(&fq->q, &nf_frags);
 169 }
 170
 171 static void nf_ct_frag6_evictor(void)
 172 {
 173         inet_frag_evictor(&nf_init_frags, &nf_frags);
 174 }
 175
 176 static void nf_ct_frag6_expire(unsigned long data)
 177 {
 178         struct nf_ct_frag6_queue *fq;
 179
 180         fq = container_of((struct inet_frag_queue *)data,
 181                         struct nf_ct_frag6_queue, q);
 182
 183         spin_lock(&fq->q.lock);
 184
 185         if (fq->q.last_in & COMPLETE)
 186                 goto out;
 187
 188         fq_kill(fq);
 189
 190 out:
 191         spin_unlock(&fq->q.lock);
 192         fq_put(fq);
 193 }
 194
 195 /* Creation primitives. */
 196
 197 static __inline__ struct nf_ct_frag6_queue *
 198 fq_find(__be32 id, struct in6_addr *src, struct in6_addr *dst)
 199 {
 200         struct inet_frag_queue *q;
 201         struct ip6_create_arg arg;
 202         unsigned int hash;
 203
 204         arg.id = id;
 205         arg.src = src;
 206         arg.dst = dst;
 207         hash = ip6qhashfn(id, src, dst);
 208
 209         q = inet_frag_find(&nf_init_frags, &nf_frags, &arg, hash);
 210         if (q == NULL)
 211                 goto oom;
 212
 213         return container_of(q, struct nf_ct_frag6_queue, q);
 214
 215 oom:
 216         pr_debug("Can't alloc new queue\n");
 217         return NULL;
 218 }
 219
 220
 221 static int nf_ct_frag6_queue(struct nf_ct_frag6_queue *fq, struct sk_buff *skb,
 222                              struct frag_hdr *fhdr, int nhoff)
 223 {
 224         struct sk_buff *prev, *next;
 225         int offset, end;
 226
 227         if (fq->q.last_in & COMPLETE) {
 228                 pr_debug("Allready completed\n");
 229                 goto err;
 230         }
 231
 232         offset = ntohs(fhdr->frag_off) & ~0x7;
 233         end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
 234                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
 235
 236         if ((unsigned int)end > IPV6_MAXPLEN) {
 237                 pr_debug("offset is too large.\n");
 238                 return -1;
 239         }
 240
 241         if (skb->ip_summed == CHECKSUM_COMPLETE) {
 242                 const unsigned char *nh = skb_network_header(skb);
 243                 skb->csum = csum_sub(skb->csum,
 244                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
 245                                                   0));
 246         }
 247
 248         /* Is this the final fragment? */
 249         if (!(fhdr->frag_off & htons(IP6_MF))) {
 250                 /* If we already have some bits beyond end
 251                  * or have different end, the segment is corrupted.
 252                  */
 253                 if (end < fq->q.len ||
 254                     ((fq->q.last_in & LAST_IN) && end != fq->q.len)) {
 255                         pr_debug("already received last fragment\n");
 256                         goto err;
 257                 }
 258                 fq->q.last_in |= LAST_IN;
 259                 fq->q.len = end;
 260         } else {
 261                 /* Check if the fragment is rounded to 8 bytes.
 262                  * Required by the RFC.
 263                  */
 264                 if (end & 0x7) {
 265                         /* RFC2460 says always send parameter problem in
 266                          * this case. -DaveM
 267                          */
 268                         pr_debug("end of fragment not rounded to 8 bytes.\n");
 269                         return -1;
 270                 }
 271                 if (end > fq->q.len) {
 272                         /* Some bits beyond end -> corruption. */
 273                         if (fq->q.last_in & LAST_IN) {
 274                                 pr_debug("last packet already reached.\n");
 275                                 goto err;
 276                         }
 277                         fq->q.len = end;
 278                 }
 279         }
 280
 281         if (end == offset)
 282                 goto err;
 283
 284         /* Point into the IP datagram 'data' part. */
 285         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) {
 286                 pr_debug("queue: message is too short.\n");
 287                 goto err;
 288         }
 289         if (pskb_trim_rcsum(skb, end - offset)) {
 290                 pr_debug("Can't trim\n");
 291                 goto err;
 292         }
 293
 294         /* Find out which fragments are in front and at the back of us
 295          * in the chain of fragments so far.  We must know where to put
 296          * this fragment, right?
 297          */
 298         prev = NULL;
 299         for (next = fq->q.fragments; next != NULL; next = next->next) {
 300                 if (NFCT_FRAG6_CB(next)->offset >= offset)
 301                         break;  /* bingo! */
 302                 prev = next;
 303         }
 304
 305         /* We found where to put this one.  Check for overlap with
 306          * preceding fragment, and, if needed, align things so that
 307          * any overlaps are eliminated.
 308          */
 309         if (prev) {
 310                 int i = (NFCT_FRAG6_CB(prev)->offset + prev->len) - offset;
 311
 312                 if (i > 0) {
 313                         offset += i;
 314                         if (end <= offset) {
 315                                 pr_debug("overlap\n");
 316                                 goto err;
 317                         }
 318                         if (!pskb_pull(skb, i)) {
 319                                 pr_debug("Can't pull\n");
 320                                 goto err;
 321                         }
 322                         if (skb->ip_summed != CHECKSUM_UNNECESSARY)
 323                                 skb->ip_summed = CHECKSUM_NONE;
 324                 }
 325         }
 326
 327         /* Look for overlap with succeeding segments.
 328          * If we can merge fragments, do it.
 329          */
 330         while (next && NFCT_FRAG6_CB(next)->offset < end) {
 331                 /* overlap is 'i' bytes */
 332                 int i = end - NFCT_FRAG6_CB(next)->offset;
 333
 334                 if (i < next->len) {
 335                         /* Eat head of the next overlapped fragment
 336                          * and leave the loop. The next ones cannot overlap.
 337                          */
 338                         pr_debug("Eat head of the overlapped parts.: %d", i);
 339                         if (!pskb_pull(next, i))
 340                                 goto err;
 341
 342                         /* next fragment */
 343                         NFCT_FRAG6_CB(next)->offset += i;
 344                         fq->q.meat -= i;
 345                         if (next->ip_summed != CHECKSUM_UNNECESSARY)
 346                                 next->ip_summed = CHECKSUM_NONE;
 347                         break;
 348                 } else {
 349                         struct sk_buff *free_it = next;
 350
 351                         /* Old fragmnet is completely overridden with
 352                          * new one drop it.
 353                          */
 354                         next = next->next;
 355
 356                         if (prev)
 357                                 prev->next = next;
 358                         else
 359                                 fq->q.fragments = next;
 360
 361                         fq->q.meat -= free_it->len;
 362                         frag_kfree_skb(free_it, NULL);
 363                 }
 364         }
 365
 366         NFCT_FRAG6_CB(skb)->offset = offset;
 367
 368         /* Insert this fragment in the chain of fragments. */
 369         skb->next = next;
 370         if (prev)
 371                 prev->next = skb;
 372         else
 373                 fq->q.fragments = skb;
 374
 375         skb->dev = NULL;
 376         fq->q.stamp = skb->tstamp;
 377         fq->q.meat += skb->len;
 378         atomic_add(skb->truesize, &nf_init_frags.mem);
 379
 380         /* The first fragment.
 381          * nhoffset is obtained from the first fragment, of course.
 382          */
 383         if (offset == 0) {
 384                 fq->nhoffset = nhoff;
 385                 fq->q.last_in |= FIRST_IN;
 386         }
 387         write_lock(&nf_frags.lock);
 388         list_move_tail(&fq->q.lru_list, &nf_init_frags.lru_list);
 389         write_unlock(&nf_frags.lock);
 390         return 0;
 391
 392 err:
 393         return -1;
 394 }
 395
 396 /*
 397  *      Check if this packet is complete.
 398  *      Returns NULL on failure by any reason, and pointer
 399  *      to current nexthdr field in reassembled frame.
 400  *
 401  *      It is called with locked fq, and caller must check that
 402  *      queue is eligible for reassembly i.e. it is not COMPLETE,
 403  *      the last and the first frames arrived and all the bits are here.
 404  */
 405 static struct sk_buff *
 406 nf_ct_frag6_reasm(struct nf_ct_frag6_queue *fq, struct net_device *dev)
 407 {
 408         struct sk_buff *fp, *op, *head = fq->q.fragments;
 409         int    payload_len;
 410
 411         fq_kill(fq);
 412
 413         BUG_TRAP(head != NULL);
 414         BUG_TRAP(NFCT_FRAG6_CB(head)->offset == 0);
 415
 416         /* Unfragmented part is taken from the first segment. */
 417         payload_len = ((head->data - skb_network_header(head)) -
 418                        sizeof(struct ipv6hdr) + fq->q.len -
 419                        sizeof(struct frag_hdr));
 420         if (payload_len > IPV6_MAXPLEN) {
 421                 pr_debug("payload len is too large.\n");
 422                 goto out_oversize;
 423         }
 424
 425         /* Head of list must not be cloned. */
 426         if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) {
 427                 pr_debug("skb is cloned but can't expand head");
 428                 goto out_oom;
 429         }
 430
 431         /* If the first fragment is fragmented itself, we split
 432          * it to two chunks: the first with data and paged part
 433          * and the second, holding only fragments. */
 434         if (skb_shinfo(head)->frag_list) {
 435                 struct sk_buff *clone;
 436                 int i, plen = 0;
 437
 438                 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) {
 439                         pr_debug("Can't alloc skb\n");
 440                         goto out_oom;
 441                 }
 442                 clone->next = head->next;
 443                 head->next = clone;
 444                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
 445                 skb_shinfo(head)->frag_list = NULL;
 446                 for (i=0; i<skb_shinfo(head)->nr_frags; i++)
 447                         plen += skb_shinfo(head)->frags[i].size;
 448                 clone->len = clone->data_len = head->data_len - plen;
 449                 head->data_len -= clone->len;
 450                 head->len -= clone->len;
 451                 clone->csum = 0;
 452                 clone->ip_summed = head->ip_summed;
 453
 454                 NFCT_FRAG6_CB(clone)->orig = NULL;
 455                 atomic_add(clone->truesize, &nf_init_frags.mem);
 456         }
 457
 458         /* We have to remove fragment header from datagram and to relocate
 459          * header in order to calculate ICV correctly. */
 460         skb_network_header(head)[fq->nhoffset] = skb_transport_header(head)[0];
 461         memmove(head->head + sizeof(struct frag_hdr), head->head,
 462                 (head->data - head->head) - sizeof(struct frag_hdr));
 463         head->mac_header += sizeof(struct frag_hdr);
 464         head->network_header += sizeof(struct frag_hdr);
 465
 466         skb_shinfo(head)->frag_list = head->next;
 467         skb_reset_transport_header(head);
 468         skb_push(head, head->data - skb_network_header(head));
 469         atomic_sub(head->truesize, &nf_init_frags.mem);
 470
 471         for (fp=head->next; fp; fp = fp->next) {
 472                 head->data_len += fp->len;
 473                 head->len += fp->len;
 474                 if (head->ip_summed != fp->ip_summed)
 475                         head->ip_summed = CHECKSUM_NONE;
 476                 else if (head->ip_summed == CHECKSUM_COMPLETE)
 477                         head->csum = csum_add(head->csum, fp->csum);
 478                 head->truesize += fp->truesize;
 479                 atomic_sub(fp->truesize, &nf_init_frags.mem);
 480         }
 481
 482         head->next = NULL;
 483         head->dev = dev;
 484         head->tstamp = fq->q.stamp;
 485         ipv6_hdr(head)->payload_len = htons(payload_len);
 486
 487         /* Yes, and fold redundant checksum back. 8) */
 488         if (head->ip_summed == CHECKSUM_COMPLETE)
 489                 head->csum = csum_partial(skb_network_header(head),
 490                                           skb_network_header_len(head),
 491                                           head->csum);
 492
 493         fq->q.fragments = NULL;
 494
 495         /* all original skbs are linked into the NFCT_FRAG6_CB(head).orig */
 496         fp = skb_shinfo(head)->frag_list;
 497         if (NFCT_FRAG6_CB(fp)->orig == NULL)
 498                 /* at above code, head skb is divided into two skbs. */
 499                 fp = fp->next;
 500
 501         op = NFCT_FRAG6_CB(head)->orig;
 502         for (; fp; fp = fp->next) {
 503                 struct sk_buff *orig = NFCT_FRAG6_CB(fp)->orig;
 504
 505                 op->next = orig;
 506                 op = orig;
 507                 NFCT_FRAG6_CB(fp)->orig = NULL;
 508         }
 509
 510         return head;
 511
 512 out_oversize:
 513         if (net_ratelimit())
 514                 printk(KERN_DEBUG "nf_ct_frag6_reasm: payload len = %d\n", payload_len);
 515         goto out_fail;
 516 out_oom:
 517         if (net_ratelimit())
 518                 printk(KERN_DEBUG "nf_ct_frag6_reasm: no memory for reassembly\n");
 519 out_fail:
 520         return NULL;
 521 }
 522
 523 /*
 524  * find the header just before Fragment Header.
 525  *
 526  * if success return 0 and set ...
 527  * (*prevhdrp): the value of "Next Header Field" in the header
 528  *              just before Fragment Header.
 529  * (*prevhoff): the offset of "Next Header Field" in the header
 530  *              just before Fragment Header.
 531  * (*fhoff)   : the offset of Fragment Header.
 532  *
 533  * Based on ipv6_skip_hdr() in net/ipv6/exthdr.c
 534  *
 535  */
 536 static int
 537 find_prev_fhdr(struct sk_buff *skb, u8 *prevhdrp, int *prevhoff, int *fhoff)
 538 {
 539         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 540         const int netoff = skb_network_offset(skb);
 541         u8 prev_nhoff = netoff + offsetof(struct ipv6hdr, nexthdr);
 542         int start = netoff + sizeof(struct ipv6hdr);
 543         int len = skb->len - start;
 544         u8 prevhdr = NEXTHDR_IPV6;
 545
 546         while (nexthdr != NEXTHDR_FRAGMENT) {
 547                 struct ipv6_opt_hdr hdr;
 548                 int hdrlen;
 549
 550                 if (!ipv6_ext_hdr(nexthdr)) {
 551                         return -1;
 552                 }
 553                 if (len < (int)sizeof(struct ipv6_opt_hdr)) {
 554                         pr_debug("too short\n");
 555                         return -1;
 556                 }
 557                 if (nexthdr == NEXTHDR_NONE) {
 558                         pr_debug("next header is none\n");
 559                         return -1;
 560                 }
 561                 if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
 562                         BUG();
 563                 if (nexthdr == NEXTHDR_AUTH)
 564                         hdrlen = (hdr.hdrlen+2)<<2;
 565                 else
 566                         hdrlen = ipv6_optlen(&hdr);
 567
 568                 prevhdr = nexthdr;
 569                 prev_nhoff = start;
 570
 571                 nexthdr = hdr.nexthdr;
 572                 len -= hdrlen;
 573                 start += hdrlen;
 574         }
 575
 576         if (len < 0)
 577                 return -1;
 578
 579         *prevhdrp = prevhdr;
 580         *prevhoff = prev_nhoff;
 581         *fhoff = start;
 582
 583         return 0;
 584 }
 585
 586 struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb)
 587 {
 588         struct sk_buff *clone;
 589         struct net_device *dev = skb->dev;
 590         struct frag_hdr *fhdr;
 591         struct nf_ct_frag6_queue *fq;
 592         struct ipv6hdr *hdr;
 593         int fhoff, nhoff;
 594         u8 prevhdr;
 595         struct sk_buff *ret_skb = NULL;
 596
 597         /* Jumbo payload inhibits frag. header */
 598         if (ipv6_hdr(skb)->payload_len == 0) {
 599                 pr_debug("payload len = 0\n");
 600                 return skb;
 601         }
 602
 603         if (find_prev_fhdr(skb, &prevhdr, &nhoff, &fhoff) < 0)
 604                 return skb;
 605
 606         clone = skb_clone(skb, GFP_ATOMIC);
 607         if (clone == NULL) {
 608                 pr_debug("Can't clone skb\n");
 609                 return skb;
 610         }
 611
 612         NFCT_FRAG6_CB(clone)->orig = skb;
 613
 614         if (!pskb_may_pull(clone, fhoff + sizeof(*fhdr))) {
 615                 pr_debug("message is too short.\n");
 616                 goto ret_orig;
 617         }
 618
 619         skb_set_transport_header(clone, fhoff);
 620         hdr = ipv6_hdr(clone);
 621         fhdr = (struct frag_hdr *)skb_transport_header(clone);
 622
 623         if (!(fhdr->frag_off & htons(0xFFF9))) {
 624                 pr_debug("Invalid fragment offset\n");
 625                 /* It is not a fragmented frame */
 626                 goto ret_orig;
 627         }
 628
 629         if (atomic_read(&nf_init_frags.mem) > nf_init_frags.high_thresh)
 630                 nf_ct_frag6_evictor();
 631
 632         fq = fq_find(fhdr->identification, &hdr->saddr, &hdr->daddr);
 633         if (fq == NULL) {
 634                 pr_debug("Can't find and can't create new queue\n");
 635                 goto ret_orig;
 636         }
 637
 638         spin_lock(&fq->q.lock);
 639
 640         if (nf_ct_frag6_queue(fq, clone, fhdr, nhoff) < 0) {
 641                 spin_unlock(&fq->q.lock);
 642                 pr_debug("Can't insert skb to queue\n");
 643                 fq_put(fq);
 644                 goto ret_orig;
 645         }
 646
 647         if (fq->q.last_in == (FIRST_IN|LAST_IN) && fq->q.meat == fq->q.len) {
 648                 ret_skb = nf_ct_frag6_reasm(fq, dev);
 649                 if (ret_skb == NULL)
 650                         pr_debug("Can't reassemble fragmented packets\n");
 651         }
 652         spin_unlock(&fq->q.lock);
 653
 654         fq_put(fq);
 655         return ret_skb;
 656
 657 ret_orig:
 658         kfree_skb(clone);
 659         return skb;
 660 }
 661
 662 void nf_ct_frag6_output(unsigned int hooknum, struct sk_buff *skb,
 663                         struct net_device *in, struct net_device *out,
 664                         int (*okfn)(struct sk_buff *))
 665 {
 666         struct sk_buff *s, *s2;
 667
 668         for (s = NFCT_FRAG6_CB(skb)->orig; s;) {
 669                 nf_conntrack_put_reasm(s->nfct_reasm);
 670                 nf_conntrack_get_reasm(skb);
 671                 s->nfct_reasm = skb;
 672
 673                 s2 = s->next;
 674                 s->next = NULL;
 675
 676                 NF_HOOK_THRESH(PF_INET6, hooknum, s, in, out, okfn,
 677                                NF_IP6_PRI_CONNTRACK_DEFRAG + 1);
 678                 s = s2;
 679         }
 680         nf_conntrack_put_reasm(skb);
 681 }
 682
 683 int nf_ct_frag6_kfree_frags(struct sk_buff *skb)
 684 {
 685         struct sk_buff *s, *s2;
 686
 687         for (s = NFCT_FRAG6_CB(skb)->orig; s; s = s2) {
 688
 689                 s2 = s->next;
 690                 kfree_skb(s);
 691         }
 692
 693         kfree_skb(skb);
 694
 695         return 0;
 696 }
 697
 698 int nf_ct_frag6_init(void)
 699 {
 700         nf_frags.hashfn = nf_hashfn;
 701         nf_frags.constructor = ip6_frag_init;
 702         nf_frags.destructor = NULL;
 703         nf_frags.skb_free = nf_skb_free;
 704         nf_frags.qsize = sizeof(struct nf_ct_frag6_queue);
 705         nf_frags.match = ip6_frag_match;
 706         nf_frags.frag_expire = nf_ct_frag6_expire;
 707         nf_frags.secret_interval = 10 * 60 * HZ;
 708         nf_init_frags.timeout = IPV6_FRAG_TIMEOUT;
 709         nf_init_frags.high_thresh = 256 * 1024;
 710         nf_init_frags.low_thresh = 192 * 1024;
 711         inet_frags_init_net(&nf_init_frags);
 712         inet_frags_init(&nf_frags);
 713
 714         return 0;
 715 }
 716
 717 void nf_ct_frag6_cleanup(void)
 718 {
 719         inet_frags_fini(&nf_frags);
 720
 721         nf_init_frags.low_thresh = 0;
 722         nf_ct_frag6_evictor();
 723 }