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   1 /*
   2  *      IPv6 fragment reassembly
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      $Id: reassembly.c,v 1.26 2001/03/07 22:00:57 davem Exp $
   9  *
  10  *      Based on: net/ipv4/ip_fragment.c
  11  *
  12  *      This program is free software; you can redistribute it and/or
  13  *      modify it under the terms of the GNU General Public License
  14  *      as published by the Free Software Foundation; either version
  15  *      2 of the License, or (at your option) any later version.
  16  */
  17
  18 /*
  19  *      Fixes:
  20  *      Andi Kleen      Make it work with multiple hosts.
  21  *                      More RFC compliance.
  22  *
  23  *      Horst von Brand Add missing #include <linux/string.h>
  24  *      Alexey Kuznetsov        SMP races, threading, cleanup.
  25  *      Patrick McHardy         LRU queue of frag heads for evictor.
  26  *      Mitsuru KANDA @USAGI    Register inet6_protocol{}.
  27  *      David Stevens and
  28  *      YOSHIFUJI,H. @USAGI     Always remove fragment header to
  29  *                              calculate ICV correctly.
  30  */
  31 #include <linux/errno.h>
  32 #include <linux/types.h>
  33 #include <linux/string.h>
  34 #include <linux/socket.h>
  35 #include <linux/sockios.h>
  36 #include <linux/jiffies.h>
  37 #include <linux/net.h>
  38 #include <linux/list.h>
  39 #include <linux/netdevice.h>
  40 #include <linux/in6.h>
  41 #include <linux/ipv6.h>
  42 #include <linux/icmpv6.h>
  43 #include <linux/random.h>
  44 #include <linux/jhash.h>
  45 #include <linux/skbuff.h>
  46
  47 #include <net/sock.h>
  48 #include <net/snmp.h>
  49
  50 #include <net/ipv6.h>
  51 #include <net/ip6_route.h>
  52 #include <net/protocol.h>
  53 #include <net/transp_v6.h>
  54 #include <net/rawv6.h>
  55 #include <net/ndisc.h>
  56 #include <net/addrconf.h>
  57 #include <net/inet_frag.h>
  58
  59 struct ip6frag_skb_cb
  60 {
  61         struct inet6_skb_parm   h;
  62         int                     offset;
  63 };
  64
  65 #define FRAG6_CB(skb)   ((struct ip6frag_skb_cb*)((skb)->cb))
  66
  67
  68 /*
  69  *      Equivalent of ipv4 struct ipq
  70  */
  71
  72 struct frag_queue
  73 {
  74         struct inet_frag_queue  q;
  75
  76         __be32                  id;             /* fragment id          */
  77         struct in6_addr         saddr;
  78         struct in6_addr         daddr;
  79
  80         int                     iif;
  81         unsigned int            csum;
  82         __u16                   nhoffset;
  83 };
  84
  85 struct inet_frags_ctl ip6_frags_ctl __read_mostly = {
  86         .high_thresh     = 256 * 1024,
  87         .low_thresh      = 192 * 1024,
  88         .timeout         = IPV6_FRAG_TIMEOUT,
  89         .secret_interval = 10 * 60 * HZ,
  90 };
  91
  92 static struct inet_frags ip6_frags;
  93
  94 int ip6_frag_nqueues(void)
  95 {
  96         return ip6_frags.nqueues;
  97 }
  98
  99 int ip6_frag_mem(void)
 100 {
 101         return atomic_read(&ip6_frags.mem);
 102 }
 103
 104 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 105                           struct net_device *dev);
 106
 107 /*
 108  * callers should be careful not to use the hash value outside the ipfrag_lock
 109  * as doing so could race with ipfrag_hash_rnd being recalculated.
 110  */
 111 static unsigned int ip6qhashfn(__be32 id, struct in6_addr *saddr,
 112                                struct in6_addr *daddr)
 113 {
 114         u32 a, b, c;
 115
 116         a = (__force u32)saddr->s6_addr32[0];
 117         b = (__force u32)saddr->s6_addr32[1];
 118         c = (__force u32)saddr->s6_addr32[2];
 119
 120         a += JHASH_GOLDEN_RATIO;
 121         b += JHASH_GOLDEN_RATIO;
 122         c += ip6_frags.rnd;
 123         __jhash_mix(a, b, c);
 124
 125         a += (__force u32)saddr->s6_addr32[3];
 126         b += (__force u32)daddr->s6_addr32[0];
 127         c += (__force u32)daddr->s6_addr32[1];
 128         __jhash_mix(a, b, c);
 129
 130         a += (__force u32)daddr->s6_addr32[2];
 131         b += (__force u32)daddr->s6_addr32[3];
 132         c += (__force u32)id;
 133         __jhash_mix(a, b, c);
 134
 135         return c & (INETFRAGS_HASHSZ - 1);
 136 }
 137
 138 static unsigned int ip6_hashfn(struct inet_frag_queue *q)
 139 {
 140         struct frag_queue *fq;
 141
 142         fq = container_of(q, struct frag_queue, q);
 143         return ip6qhashfn(fq->id, &fq->saddr, &fq->daddr);
 144 }
 145
 146 int ip6_frag_equal(struct inet_frag_queue *q1, struct inet_frag_queue *q2)
 147 {
 148         struct frag_queue *fq1, *fq2;
 149
 150         fq1 = container_of(q1, struct frag_queue, q);
 151         fq2 = container_of(q2, struct frag_queue, q);
 152         return (fq1->id == fq2->id &&
 153                         ipv6_addr_equal(&fq2->saddr, &fq1->saddr) &&
 154                         ipv6_addr_equal(&fq2->daddr, &fq1->daddr));
 155 }
 156 EXPORT_SYMBOL(ip6_frag_equal);
 157
 158 int ip6_frag_match(struct inet_frag_queue *q, void *a)
 159 {
 160         struct frag_queue *fq;
 161         struct ip6_create_arg *arg = a;
 162
 163         fq = container_of(q, struct frag_queue, q);
 164         return (fq->id == arg->id &&
 165                         ipv6_addr_equal(&fq->saddr, arg->src) &&
 166                         ipv6_addr_equal(&fq->daddr, arg->dst));
 167 }
 168 EXPORT_SYMBOL(ip6_frag_match);
 169
 170 /* Memory Tracking Functions. */
 171 static inline void frag_kfree_skb(struct sk_buff *skb, int *work)
 172 {
 173         if (work)
 174                 *work -= skb->truesize;
 175         atomic_sub(skb->truesize, &ip6_frags.mem);
 176         kfree_skb(skb);
 177 }
 178
 179 void ip6_frag_init(struct inet_frag_queue *q, void *a)
 180 {
 181         struct frag_queue *fq = container_of(q, struct frag_queue, q);
 182         struct ip6_create_arg *arg = a;
 183
 184         fq->id = arg->id;
 185         ipv6_addr_copy(&fq->saddr, arg->src);
 186         ipv6_addr_copy(&fq->daddr, arg->dst);
 187 }
 188 EXPORT_SYMBOL(ip6_frag_init);
 189
 190 static void ip6_frag_free(struct inet_frag_queue *fq)
 191 {
 192         kfree(container_of(fq, struct frag_queue, q));
 193 }
 194
 195 /* Destruction primitives. */
 196
 197 static __inline__ void fq_put(struct frag_queue *fq)
 198 {
 199         inet_frag_put(&fq->q, &ip6_frags);
 200 }
 201
 202 /* Kill fq entry. It is not destroyed immediately,
 203  * because caller (and someone more) holds reference count.
 204  */
 205 static __inline__ void fq_kill(struct frag_queue *fq)
 206 {
 207         inet_frag_kill(&fq->q, &ip6_frags);
 208 }
 209
 210 static void ip6_evictor(struct inet6_dev *idev)
 211 {
 212         int evicted;
 213
 214         evicted = inet_frag_evictor(&ip6_frags);
 215         if (evicted)
 216                 IP6_ADD_STATS_BH(idev, IPSTATS_MIB_REASMFAILS, evicted);
 217 }
 218
 219 static void ip6_frag_expire(unsigned long data)
 220 {
 221         struct frag_queue *fq;
 222         struct net_device *dev = NULL;
 223
 224         fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
 225
 226         spin_lock(&fq->q.lock);
 227
 228         if (fq->q.last_in & COMPLETE)
 229                 goto out;
 230
 231         fq_kill(fq);
 232
 233         dev = dev_get_by_index(&init_net, fq->iif);
 234         if (!dev)
 235                 goto out;
 236
 237         rcu_read_lock();
 238         IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
 239         IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
 240         rcu_read_unlock();
 241
 242         /* Don't send error if the first segment did not arrive. */
 243         if (!(fq->q.last_in&FIRST_IN) || !fq->q.fragments)
 244                 goto out;
 245
 246         /*
 247            But use as source device on which LAST ARRIVED
 248            segment was received. And do not use fq->dev
 249            pointer directly, device might already disappeared.
 250          */
 251         fq->q.fragments->dev = dev;
 252         icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0, dev);
 253 out:
 254         if (dev)
 255                 dev_put(dev);
 256         spin_unlock(&fq->q.lock);
 257         fq_put(fq);
 258 }
 259
 260 static __inline__ struct frag_queue *
 261 fq_find(__be32 id, struct in6_addr *src, struct in6_addr *dst,
 262         struct inet6_dev *idev)
 263 {
 264         struct inet_frag_queue *q;
 265         struct ip6_create_arg arg;
 266         unsigned int hash;
 267
 268         arg.id = id;
 269         arg.src = src;
 270         arg.dst = dst;
 271         hash = ip6qhashfn(id, src, dst);
 272
 273         q = inet_frag_find(&ip6_frags, &arg, hash);
 274         if (q == NULL)
 275                 goto oom;
 276
 277         return container_of(q, struct frag_queue, q);
 278
 279 oom:
 280         IP6_INC_STATS_BH(idev, IPSTATS_MIB_REASMFAILS);
 281         return NULL;
 282 }
 283
 284 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
 285                            struct frag_hdr *fhdr, int nhoff)
 286 {
 287         struct sk_buff *prev, *next;
 288         struct net_device *dev;
 289         int offset, end;
 290
 291         if (fq->q.last_in & COMPLETE)
 292                 goto err;
 293
 294         offset = ntohs(fhdr->frag_off) & ~0x7;
 295         end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
 296                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
 297
 298         if ((unsigned int)end > IPV6_MAXPLEN) {
 299                 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
 300                                  IPSTATS_MIB_INHDRERRORS);
 301                 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
 302                                   ((u8 *)&fhdr->frag_off -
 303                                    skb_network_header(skb)));
 304                 return -1;
 305         }
 306
 307         if (skb->ip_summed == CHECKSUM_COMPLETE) {
 308                 const unsigned char *nh = skb_network_header(skb);
 309                 skb->csum = csum_sub(skb->csum,
 310                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
 311                                                   0));
 312         }
 313
 314         /* Is this the final fragment? */
 315         if (!(fhdr->frag_off & htons(IP6_MF))) {
 316                 /* If we already have some bits beyond end
 317                  * or have different end, the segment is corrupted.
 318                  */
 319                 if (end < fq->q.len ||
 320                     ((fq->q.last_in & LAST_IN) && end != fq->q.len))
 321                         goto err;
 322                 fq->q.last_in |= LAST_IN;
 323                 fq->q.len = end;
 324         } else {
 325                 /* Check if the fragment is rounded to 8 bytes.
 326                  * Required by the RFC.
 327                  */
 328                 if (end & 0x7) {
 329                         /* RFC2460 says always send parameter problem in
 330                          * this case. -DaveM
 331                          */
 332                         IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
 333                                          IPSTATS_MIB_INHDRERRORS);
 334                         icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
 335                                           offsetof(struct ipv6hdr, payload_len));
 336                         return -1;
 337                 }
 338                 if (end > fq->q.len) {
 339                         /* Some bits beyond end -> corruption. */
 340                         if (fq->q.last_in & LAST_IN)
 341                                 goto err;
 342                         fq->q.len = end;
 343                 }
 344         }
 345
 346         if (end == offset)
 347                 goto err;
 348
 349         /* Point into the IP datagram 'data' part. */
 350         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
 351                 goto err;
 352
 353         if (pskb_trim_rcsum(skb, end - offset))
 354                 goto err;
 355
 356         /* Find out which fragments are in front and at the back of us
 357          * in the chain of fragments so far.  We must know where to put
 358          * this fragment, right?
 359          */
 360         prev = NULL;
 361         for(next = fq->q.fragments; next != NULL; next = next->next) {
 362                 if (FRAG6_CB(next)->offset >= offset)
 363                         break;  /* bingo! */
 364                 prev = next;
 365         }
 366
 367         /* We found where to put this one.  Check for overlap with
 368          * preceding fragment, and, if needed, align things so that
 369          * any overlaps are eliminated.
 370          */
 371         if (prev) {
 372                 int i = (FRAG6_CB(prev)->offset + prev->len) - offset;
 373
 374                 if (i > 0) {
 375                         offset += i;
 376                         if (end <= offset)
 377                                 goto err;
 378                         if (!pskb_pull(skb, i))
 379                                 goto err;
 380                         if (skb->ip_summed != CHECKSUM_UNNECESSARY)
 381                                 skb->ip_summed = CHECKSUM_NONE;
 382                 }
 383         }
 384
 385         /* Look for overlap with succeeding segments.
 386          * If we can merge fragments, do it.
 387          */
 388         while (next && FRAG6_CB(next)->offset < end) {
 389                 int i = end - FRAG6_CB(next)->offset; /* overlap is 'i' bytes */
 390
 391                 if (i < next->len) {
 392                         /* Eat head of the next overlapped fragment
 393                          * and leave the loop. The next ones cannot overlap.
 394                          */
 395                         if (!pskb_pull(next, i))
 396                                 goto err;
 397                         FRAG6_CB(next)->offset += i;    /* next fragment */
 398                         fq->q.meat -= i;
 399                         if (next->ip_summed != CHECKSUM_UNNECESSARY)
 400                                 next->ip_summed = CHECKSUM_NONE;
 401                         break;
 402                 } else {
 403                         struct sk_buff *free_it = next;
 404
 405                         /* Old fragment is completely overridden with
 406                          * new one drop it.
 407                          */
 408                         next = next->next;
 409
 410                         if (prev)
 411                                 prev->next = next;
 412                         else
 413                                 fq->q.fragments = next;
 414
 415                         fq->q.meat -= free_it->len;
 416                         frag_kfree_skb(free_it, NULL);
 417                 }
 418         }
 419
 420         FRAG6_CB(skb)->offset = offset;
 421
 422         /* Insert this fragment in the chain of fragments. */
 423         skb->next = next;
 424         if (prev)
 425                 prev->next = skb;
 426         else
 427                 fq->q.fragments = skb;
 428
 429         dev = skb->dev;
 430         if (dev) {
 431                 fq->iif = dev->ifindex;
 432                 skb->dev = NULL;
 433         }
 434         fq->q.stamp = skb->tstamp;
 435         fq->q.meat += skb->len;
 436         atomic_add(skb->truesize, &ip6_frags.mem);
 437
 438         /* The first fragment.
 439          * nhoffset is obtained from the first fragment, of course.
 440          */
 441         if (offset == 0) {
 442                 fq->nhoffset = nhoff;
 443                 fq->q.last_in |= FIRST_IN;
 444         }
 445
 446         if (fq->q.last_in == (FIRST_IN | LAST_IN) && fq->q.meat == fq->q.len)
 447                 return ip6_frag_reasm(fq, prev, dev);
 448
 449         write_lock(&ip6_frags.lock);
 450         list_move_tail(&fq->q.lru_list, &ip6_frags.lru_list);
 451         write_unlock(&ip6_frags.lock);
 452         return -1;
 453
 454 err:
 455         IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMFAILS);
 456         kfree_skb(skb);
 457         return -1;
 458 }
 459
 460 /*
 461  *      Check if this packet is complete.
 462  *      Returns NULL on failure by any reason, and pointer
 463  *      to current nexthdr field in reassembled frame.
 464  *
 465  *      It is called with locked fq, and caller must check that
 466  *      queue is eligible for reassembly i.e. it is not COMPLETE,
 467  *      the last and the first frames arrived and all the bits are here.
 468  */
 469 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 470                           struct net_device *dev)
 471 {
 472         struct sk_buff *fp, *head = fq->q.fragments;
 473         int    payload_len;
 474         unsigned int nhoff;
 475
 476         fq_kill(fq);
 477
 478         /* Make the one we just received the head. */
 479         if (prev) {
 480                 head = prev->next;
 481                 fp = skb_clone(head, GFP_ATOMIC);
 482
 483                 if (!fp)
 484                         goto out_oom;
 485
 486                 fp->next = head->next;
 487                 prev->next = fp;
 488
 489                 skb_morph(head, fq->q.fragments);
 490                 head->next = fq->q.fragments->next;
 491
 492                 kfree_skb(fq->q.fragments);
 493                 fq->q.fragments = head;
 494         }
 495
 496         BUG_TRAP(head != NULL);
 497         BUG_TRAP(FRAG6_CB(head)->offset == 0);
 498
 499         /* Unfragmented part is taken from the first segment. */
 500         payload_len = ((head->data - skb_network_header(head)) -
 501                        sizeof(struct ipv6hdr) + fq->q.len -
 502                        sizeof(struct frag_hdr));
 503         if (payload_len > IPV6_MAXPLEN)
 504                 goto out_oversize;
 505
 506         /* Head of list must not be cloned. */
 507         if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
 508                 goto out_oom;
 509
 510         /* If the first fragment is fragmented itself, we split
 511          * it to two chunks: the first with data and paged part
 512          * and the second, holding only fragments. */
 513         if (skb_shinfo(head)->frag_list) {
 514                 struct sk_buff *clone;
 515                 int i, plen = 0;
 516
 517                 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
 518                         goto out_oom;
 519                 clone->next = head->next;
 520                 head->next = clone;
 521                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
 522                 skb_shinfo(head)->frag_list = NULL;
 523                 for (i=0; i<skb_shinfo(head)->nr_frags; i++)
 524                         plen += skb_shinfo(head)->frags[i].size;
 525                 clone->len = clone->data_len = head->data_len - plen;
 526                 head->data_len -= clone->len;
 527                 head->len -= clone->len;
 528                 clone->csum = 0;
 529                 clone->ip_summed = head->ip_summed;
 530                 atomic_add(clone->truesize, &ip6_frags.mem);
 531         }
 532
 533         /* We have to remove fragment header from datagram and to relocate
 534          * header in order to calculate ICV correctly. */
 535         nhoff = fq->nhoffset;
 536         skb_network_header(head)[nhoff] = skb_transport_header(head)[0];
 537         memmove(head->head + sizeof(struct frag_hdr), head->head,
 538                 (head->data - head->head) - sizeof(struct frag_hdr));
 539         head->mac_header += sizeof(struct frag_hdr);
 540         head->network_header += sizeof(struct frag_hdr);
 541
 542         skb_shinfo(head)->frag_list = head->next;
 543         skb_reset_transport_header(head);
 544         skb_push(head, head->data - skb_network_header(head));
 545         atomic_sub(head->truesize, &ip6_frags.mem);
 546
 547         for (fp=head->next; fp; fp = fp->next) {
 548                 head->data_len += fp->len;
 549                 head->len += fp->len;
 550                 if (head->ip_summed != fp->ip_summed)
 551                         head->ip_summed = CHECKSUM_NONE;
 552                 else if (head->ip_summed == CHECKSUM_COMPLETE)
 553                         head->csum = csum_add(head->csum, fp->csum);
 554                 head->truesize += fp->truesize;
 555                 atomic_sub(fp->truesize, &ip6_frags.mem);
 556         }
 557
 558         head->next = NULL;
 559         head->dev = dev;
 560         head->tstamp = fq->q.stamp;
 561         ipv6_hdr(head)->payload_len = htons(payload_len);
 562         IP6CB(head)->nhoff = nhoff;
 563
 564         /* Yes, and fold redundant checksum back. 8) */
 565         if (head->ip_summed == CHECKSUM_COMPLETE)
 566                 head->csum = csum_partial(skb_network_header(head),
 567                                           skb_network_header_len(head),
 568                                           head->csum);
 569
 570         rcu_read_lock();
 571         IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
 572         rcu_read_unlock();
 573         fq->q.fragments = NULL;
 574         return 1;
 575
 576 out_oversize:
 577         if (net_ratelimit())
 578                 printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len);
 579         goto out_fail;
 580 out_oom:
 581         if (net_ratelimit())
 582                 printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n");
 583 out_fail:
 584         rcu_read_lock();
 585         IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
 586         rcu_read_unlock();
 587         return -1;
 588 }
 589
 590 static int ipv6_frag_rcv(struct sk_buff *skb)
 591 {
 592         struct frag_hdr *fhdr;
 593         struct frag_queue *fq;
 594         struct ipv6hdr *hdr = ipv6_hdr(skb);
 595
 596         IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMREQDS);
 597
 598         /* Jumbo payload inhibits frag. header */
 599         if (hdr->payload_len==0) {
 600                 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS);
 601                 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
 602                                   skb_network_header_len(skb));
 603                 return -1;
 604         }
 605         if (!pskb_may_pull(skb, (skb_transport_offset(skb) +
 606                                  sizeof(struct frag_hdr)))) {
 607                 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS);
 608                 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
 609                                   skb_network_header_len(skb));
 610                 return -1;
 611         }
 612
 613         hdr = ipv6_hdr(skb);
 614         fhdr = (struct frag_hdr *)skb_transport_header(skb);
 615
 616         if (!(fhdr->frag_off & htons(0xFFF9))) {
 617                 /* It is not a fragmented frame */
 618                 skb->transport_header += sizeof(struct frag_hdr);
 619                 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMOKS);
 620
 621                 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb);
 622                 return 1;
 623         }
 624
 625         if (atomic_read(&ip6_frags.mem) > ip6_frags_ctl.high_thresh)
 626                 ip6_evictor(ip6_dst_idev(skb->dst));
 627
 628         if ((fq = fq_find(fhdr->identification, &hdr->saddr, &hdr->daddr,
 629                           ip6_dst_idev(skb->dst))) != NULL) {
 630                 int ret;
 631
 632                 spin_lock(&fq->q.lock);
 633
 634                 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
 635
 636                 spin_unlock(&fq->q.lock);
 637                 fq_put(fq);
 638                 return ret;
 639         }
 640
 641         IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMFAILS);
 642         kfree_skb(skb);
 643         return -1;
 644 }
 645
 646 static struct inet6_protocol frag_protocol =
 647 {
 648         .handler        =       ipv6_frag_rcv,
 649         .flags          =       INET6_PROTO_NOPOLICY,
 650 };
 651
 652 void __init ipv6_frag_init(void)
 653 {
 654         if (inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT) < 0)
 655                 printk(KERN_ERR "ipv6_frag_init: Could not register protocol\n");
 656
 657         ip6_frags.ctl = &ip6_frags_ctl;
 658         ip6_frags.hashfn = ip6_hashfn;
 659         ip6_frags.constructor = ip6_frag_init;
 660         ip6_frags.destructor = ip6_frag_free;
 661         ip6_frags.skb_free = NULL;
 662         ip6_frags.qsize = sizeof(struct frag_queue);
 663         ip6_frags.match = ip6_frag_match;
 664         ip6_frags.equal = ip6_frag_equal;
 665         ip6_frags.frag_expire = ip6_frag_expire;
 666         inet_frags_init(&ip6_frags);
 667 }