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