net/ipv6/netfilter/nf_conntrack_reasm.c

   1 /*
   2  * IPv6 fragment reassembly for connection tracking
   3  *
   4  * Copyright (C)2004 USAGI/WIDE Project
   5  *
   6  * Author:
   7  *      Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
   8  *
   9  * Based on: net/ipv6/reassembly.c
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version
  14  * 2 of the License, or (at your option) any later version.
  15  */
  16
  17 #include <linux/errno.h>
  18 #include <linux/types.h>
  19 #include <linux/string.h>
  20 #include <linux/socket.h>
  21 #include <linux/sockios.h>
  22 #include <linux/jiffies.h>
  23 #include <linux/net.h>
  24 #include <linux/list.h>
  25 #include <linux/netdevice.h>
  26 #include <linux/in6.h>
  27 #include <linux/ipv6.h>
  28 #include <linux/icmpv6.h>
  29 #include <linux/random.h>
  30 #include <linux/jhash.h>
  31
  32 #include <net/sock.h>
  33 #include <net/snmp.h>
  34 #include <net/inet_frag.h>
  35
  36 #include <net/ipv6.h>
  37 #include <net/protocol.h>
  38 #include <net/transp_v6.h>
  39 #include <net/rawv6.h>
  40 #include <net/ndisc.h>
  41 #include <net/addrconf.h>
  42 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
  43 #include <linux/sysctl.h>
  44 #include <linux/netfilter.h>
  45 #include <linux/netfilter_ipv6.h>
  46 #include <linux/kernel.h>
  47 #include <linux/module.h>
  48
  49 #define NF_CT_FRAG6_HIGH_THRESH 262144 /* == 256*1024 */
  50 #define NF_CT_FRAG6_LOW_THRESH 196608  /* == 192*1024 */
  51 #define NF_CT_FRAG6_TIMEOUT IPV6_FRAG_TIMEOUT
  52
  53 struct nf_ct_frag6_skb_cb
  54 {
  55         struct inet6_skb_parm   h;
  56         int                     offset;
  57         struct sk_buff          *orig;
  58 };
  59
  60 #define NFCT_FRAG6_CB(skb)      ((struct nf_ct_frag6_skb_cb*)((skb)->cb))
  61
  62 struct nf_ct_frag6_queue
  63 {
  64         struct inet_frag_queue  q;
  65
  66         __be32                  id;             /* fragment id          */
  67         struct in6_addr         saddr;
  68         struct in6_addr         daddr;
  69
  70         unsigned int            csum;
  71         __u16                   nhoffset;
  72 };
  73
  74 static struct inet_frags nf_frags;
  75 static struct netns_frags nf_init_frags;
  76
  77 #ifdef CONFIG_SYSCTL
  78 struct ctl_table nf_ct_ipv6_sysctl_table[] = {
  79         {
  80                 .procname       = "nf_conntrack_frag6_timeout",
  81                 .data           = &nf_init_frags.timeout,
  82                 .maxlen         = sizeof(unsigned int),
  83                 .mode           = 0644,
  84                 .proc_handler   = &proc_dointvec_jiffies,
  85         },
  86         {
  87                 .ctl_name       = NET_NF_CONNTRACK_FRAG6_LOW_THRESH,
  88                 .procname       = "nf_conntrack_frag6_low_thresh",
  89                 .data           = &nf_init_frags.low_thresh,
  90                 .maxlen         = sizeof(unsigned int),
  91                 .mode           = 0644,
  92                 .proc_handler   = &proc_dointvec,
  93         },
  94         {
  95                 .ctl_name       = NET_NF_CONNTRACK_FRAG6_HIGH_THRESH,
  96                 .procname       = "nf_conntrack_frag6_high_thresh",
  97                 .data           = &nf_init_frags.high_thresh,
  98                 .maxlen         = sizeof(unsigned int),
  99                 .mode           = 0644,
 100                 .proc_handler   = &proc_dointvec,
 101         },
 102         { .ctl_name = 0 }
 103 };
 104 #endif
 105
 106 static unsigned int ip6qhashfn(__be32 id, 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
 211         read_lock_bh(&nf_frags.lock);
 212         hash = ip6qhashfn(id, src, dst);
 213
 214         q = inet_frag_find(&nf_init_frags, &nf_frags, &arg, hash);
 215         local_bh_enable();
 216         if (q == NULL)
 217                 goto oom;
 218
 219         return container_of(q, struct nf_ct_frag6_queue, q);
 220
 221 oom:
 222         pr_debug("Can't alloc new queue\n");
 223         return NULL;
 224 }
 225
 226
 227 static int nf_ct_frag6_queue(struct nf_ct_frag6_queue *fq, struct sk_buff *skb,
 228                              const struct frag_hdr *fhdr, int nhoff)
 229 {
 230         struct sk_buff *prev, *next;
 231         int offset, end;
 232
 233         if (fq->q.last_in & INET_FRAG_COMPLETE) {
 234                 pr_debug("Allready completed\n");
 235                 goto err;
 236         }
 237
 238         offset = ntohs(fhdr->frag_off) & ~0x7;
 239         end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
 240                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
 241
 242         if ((unsigned int)end > IPV6_MAXPLEN) {
 243                 pr_debug("offset is too large.\n");
 244                 return -1;
 245         }
 246
 247         if (skb->ip_summed == CHECKSUM_COMPLETE) {
 248                 const unsigned char *nh = skb_network_header(skb);
 249                 skb->csum = csum_sub(skb->csum,
 250                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
 251                                                   0));
 252         }
 253
 254         /* Is this the final fragment? */
 255         if (!(fhdr->frag_off & htons(IP6_MF))) {
 256                 /* If we already have some bits beyond end
 257                  * or have different end, the segment is corrupted.
 258                  */
 259                 if (end < fq->q.len ||
 260                     ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len)) {
 261                         pr_debug("already received last fragment\n");
 262                         goto err;
 263                 }
 264                 fq->q.last_in |= INET_FRAG_LAST_IN;
 265                 fq->q.len = end;
 266         } else {
 267                 /* Check if the fragment is rounded to 8 bytes.
 268                  * Required by the RFC.
 269                  */
 270                 if (end & 0x7) {
 271                         /* RFC2460 says always send parameter problem in
 272                          * this case. -DaveM
 273                          */
 274                         pr_debug("end of fragment not rounded to 8 bytes.\n");
 275                         return -1;
 276                 }
 277                 if (end > fq->q.len) {
 278                         /* Some bits beyond end -> corruption. */
 279                         if (fq->q.last_in & INET_FRAG_LAST_IN) {
 280                                 pr_debug("last packet already reached.\n");
 281                                 goto err;
 282                         }
 283                         fq->q.len = end;
 284                 }
 285         }
 286
 287         if (end == offset)
 288                 goto err;
 289
 290         /* Point into the IP datagram 'data' part. */
 291         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) {
 292                 pr_debug("queue: message is too short.\n");
 293                 goto err;
 294         }
 295         if (pskb_trim_rcsum(skb, end - offset)) {
 296                 pr_debug("Can't trim\n");
 297                 goto err;
 298         }
 299
 300         /* Find out which fragments are in front and at the back of us
 301          * in the chain of fragments so far.  We must know where to put
 302          * this fragment, right?
 303          */
 304         prev = NULL;
 305         for (next = fq->q.fragments; next != NULL; next = next->next) {
 306                 if (NFCT_FRAG6_CB(next)->offset >= offset)
 307                         break;  /* bingo! */
 308                 prev = next;
 309         }
 310
 311         /* We found where to put this one.  Check for overlap with
 312          * preceding fragment, and, if needed, align things so that
 313          * any overlaps are eliminated.
 314          */
 315         if (prev) {
 316                 int i = (NFCT_FRAG6_CB(prev)->offset + prev->len) - offset;
 317
 318                 if (i > 0) {
 319                         offset += i;
 320                         if (end <= offset) {
 321                                 pr_debug("overlap\n");
 322                                 goto err;
 323                         }
 324                         if (!pskb_pull(skb, i)) {
 325                                 pr_debug("Can't pull\n");
 326                                 goto err;
 327                         }
 328                         if (skb->ip_summed != CHECKSUM_UNNECESSARY)
 329                                 skb->ip_summed = CHECKSUM_NONE;
 330                 }
 331         }
 332
 333         /* Look for overlap with succeeding segments.
 334          * If we can merge fragments, do it.
 335          */
 336         while (next && NFCT_FRAG6_CB(next)->offset < end) {
 337                 /* overlap is 'i' bytes */
 338                 int i = end - NFCT_FRAG6_CB(next)->offset;
 339
 340                 if (i < next->len) {
 341                         /* Eat head of the next overlapped fragment
 342                          * and leave the loop. The next ones cannot overlap.
 343                          */
 344                         pr_debug("Eat head of the overlapped parts.: %d", i);
 345                         if (!pskb_pull(next, i))
 346                                 goto err;
 347
 348                         /* next fragment */
 349                         NFCT_FRAG6_CB(next)->offset += i;
 350                         fq->q.meat -= i;
 351                         if (next->ip_summed != CHECKSUM_UNNECESSARY)
 352                                 next->ip_summed = CHECKSUM_NONE;
 353                         break;
 354                 } else {
 355                         struct sk_buff *free_it = next;
 356
 357                         /* Old fragmnet is completely overridden with
 358                          * new one drop it.
 359                          */
 360                         next = next->next;
 361
 362                         if (prev)
 363                                 prev->next = next;
 364                         else
 365                                 fq->q.fragments = next;
 366
 367                         fq->q.meat -= free_it->len;
 368                         frag_kfree_skb(free_it, NULL);
 369                 }
 370         }
 371
 372         NFCT_FRAG6_CB(skb)->offset = offset;
 373
 374         /* Insert this fragment in the chain of fragments. */
 375         skb->next = next;
 376         if (prev)
 377                 prev->next = skb;
 378         else
 379                 fq->q.fragments = skb;
 380
 381         skb->dev = NULL;
 382         fq->q.stamp = skb->tstamp;
 383         fq->q.meat += skb->len;
 384         atomic_add(skb->truesize, &nf_init_frags.mem);
 385
 386         /* The first fragment.
 387          * nhoffset is obtained from the first fragment, of course.
 388          */
 389         if (offset == 0) {
 390                 fq->nhoffset = nhoff;
 391                 fq->q.last_in |= INET_FRAG_FIRST_IN;
 392         }
 393         write_lock(&nf_frags.lock);
 394         list_move_tail(&fq->q.lru_list, &nf_init_frags.lru_list);
 395         write_unlock(&nf_frags.lock);
 396         return 0;
 397
 398 err:
 399         return -1;
 400 }
 401
 402 /*
 403  *      Check if this packet is complete.
 404  *      Returns NULL on failure by any reason, and pointer
 405  *      to current nexthdr field in reassembled frame.
 406  *
 407  *      It is called with locked fq, and caller must check that
 408  *      queue is eligible for reassembly i.e. it is not COMPLETE,
 409  *      the last and the first frames arrived and all the bits are here.
 410  */
 411 static struct sk_buff *
 412 nf_ct_frag6_reasm(struct nf_ct_frag6_queue *fq, struct net_device *dev)
 413 {
 414         struct sk_buff *fp, *op, *head = fq->q.fragments;
 415         int    payload_len;
 416
 417         fq_kill(fq);
 418
 419         BUG_TRAP(head != NULL);
 420         BUG_TRAP(NFCT_FRAG6_CB(head)->offset == 0);
 421
 422         /* Unfragmented part is taken from the first segment. */
 423         payload_len = ((head->data - skb_network_header(head)) -
 424                        sizeof(struct ipv6hdr) + fq->q.len -
 425                        sizeof(struct frag_hdr));
 426         if (payload_len > IPV6_MAXPLEN) {
 427                 pr_debug("payload len is too large.\n");
 428                 goto out_oversize;
 429         }
 430
 431         /* Head of list must not be cloned. */
 432         if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC)) {
 433                 pr_debug("skb is cloned but can't expand head");
 434                 goto out_oom;
 435         }
 436
 437         /* If the first fragment is fragmented itself, we split
 438          * it to two chunks: the first with data and paged part
 439          * and the second, holding only fragments. */
 440         if (skb_shinfo(head)->frag_list) {
 441                 struct sk_buff *clone;
 442                 int i, plen = 0;
 443
 444                 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL) {
 445                         pr_debug("Can't alloc skb\n");
 446                         goto out_oom;
 447                 }
 448                 clone->next = head->next;
 449                 head->next = clone;
 450                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
 451                 skb_shinfo(head)->frag_list = NULL;
 452                 for (i=0; i<skb_shinfo(head)->nr_frags; i++)
 453                         plen += skb_shinfo(head)->frags[i].size;
 454                 clone->len = clone->data_len = head->data_len - plen;
 455                 head->data_len -= clone->len;
 456                 head->len -= clone->len;
 457                 clone->csum = 0;
 458                 clone->ip_summed = head->ip_summed;
 459
 460                 NFCT_FRAG6_CB(clone)->orig = NULL;
 461                 atomic_add(clone->truesize, &nf_init_frags.mem);
 462         }
 463
 464         /* We have to remove fragment header from datagram and to relocate
 465          * header in order to calculate ICV correctly. */
 466         skb_network_header(head)[fq->nhoffset] = skb_transport_header(head)[0];
 467         memmove(head->head + sizeof(struct frag_hdr), head->head,
 468                 (head->data - head->head) - sizeof(struct frag_hdr));
 469         head->mac_header += sizeof(struct frag_hdr);
 470         head->network_header += sizeof(struct frag_hdr);
 471
 472         skb_shinfo(head)->frag_list = head->next;
 473         skb_reset_transport_header(head);
 474         skb_push(head, head->data - skb_network_header(head));
 475         atomic_sub(head->truesize, &nf_init_frags.mem);
 476
 477         for (fp=head->next; fp; fp = fp->next) {
 478                 head->data_len += fp->len;
 479                 head->len += fp->len;
 480                 if (head->ip_summed != fp->ip_summed)
 481                         head->ip_summed = CHECKSUM_NONE;
 482                 else if (head->ip_summed == CHECKSUM_COMPLETE)
 483                         head->csum = csum_add(head->csum, fp->csum);
 484                 head->truesize += fp->truesize;
 485                 atomic_sub(fp->truesize, &nf_init_frags.mem);
 486         }
 487
 488         head->next = NULL;
 489         head->dev = dev;
 490         head->tstamp = fq->q.stamp;
 491         ipv6_hdr(head)->payload_len = htons(payload_len);
 492
 493         /* Yes, and fold redundant checksum back. 8) */
 494         if (head->ip_summed == CHECKSUM_COMPLETE)
 495                 head->csum = csum_partial(skb_network_header(head),
 496                                           skb_network_header_len(head),
 497                                           head->csum);
 498
 499         fq->q.fragments = NULL;
 500
 501         /* all original skbs are linked into the NFCT_FRAG6_CB(head).orig */
 502         fp = skb_shinfo(head)->frag_list;
 503         if (NFCT_FRAG6_CB(fp)->orig == NULL)
 504                 /* at above code, head skb is divided into two skbs. */
 505                 fp = fp->next;
 506
 507         op = NFCT_FRAG6_CB(head)->orig;
 508         for (; fp; fp = fp->next) {
 509                 struct sk_buff *orig = NFCT_FRAG6_CB(fp)->orig;
 510
 511                 op->next = orig;
 512                 op = orig;
 513                 NFCT_FRAG6_CB(fp)->orig = NULL;
 514         }
 515
 516         return head;
 517
 518 out_oversize:
 519         if (net_ratelimit())
 520                 printk(KERN_DEBUG "nf_ct_frag6_reasm: payload len = %d\n", payload_len);
 521         goto out_fail;
 522 out_oom:
 523         if (net_ratelimit())
 524                 printk(KERN_DEBUG "nf_ct_frag6_reasm: no memory for reassembly\n");
 525 out_fail:
 526         return NULL;
 527 }
 528
 529 /*
 530  * find the header just before Fragment Header.
 531  *
 532  * if success return 0 and set ...
 533  * (*prevhdrp): the value of "Next Header Field" in the header
 534  *              just before Fragment Header.
 535  * (*prevhoff): the offset of "Next Header Field" in the header
 536  *              just before Fragment Header.
 537  * (*fhoff)   : the offset of Fragment Header.
 538  *
 539  * Based on ipv6_skip_hdr() in net/ipv6/exthdr.c
 540  *
 541  */
 542 static int
 543 find_prev_fhdr(struct sk_buff *skb, u8 *prevhdrp, int *prevhoff, int *fhoff)
 544 {
 545         u8 nexthdr = ipv6_hdr(skb)->nexthdr;
 546         const int netoff = skb_network_offset(skb);
 547         u8 prev_nhoff = netoff + offsetof(struct ipv6hdr, nexthdr);
 548         int start = netoff + sizeof(struct ipv6hdr);
 549         int len = skb->len - start;
 550         u8 prevhdr = NEXTHDR_IPV6;
 551
 552         while (nexthdr != NEXTHDR_FRAGMENT) {
 553                 struct ipv6_opt_hdr hdr;
 554                 int hdrlen;
 555
 556                 if (!ipv6_ext_hdr(nexthdr)) {
 557                         return -1;
 558                 }
 559                 if (len < (int)sizeof(struct ipv6_opt_hdr)) {
 560                         pr_debug("too short\n");
 561                         return -1;
 562                 }
 563                 if (nexthdr == NEXTHDR_NONE) {
 564                         pr_debug("next header is none\n");
 565                         return -1;
 566                 }
 567                 if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
 568                         BUG();
 569                 if (nexthdr == NEXTHDR_AUTH)
 570                         hdrlen = (hdr.hdrlen+2)<<2;
 571                 else
 572                         hdrlen = ipv6_optlen(&hdr);
 573
 574                 prevhdr = nexthdr;
 575                 prev_nhoff = start;
 576
 577                 nexthdr = hdr.nexthdr;
 578                 len -= hdrlen;
 579                 start += hdrlen;
 580         }
 581
 582         if (len < 0)
 583                 return -1;
 584
 585         *prevhdrp = prevhdr;
 586         *prevhoff = prev_nhoff;
 587         *fhoff = start;
 588
 589         return 0;
 590 }
 591
 592 struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb)
 593 {
 594         struct sk_buff *clone;
 595         struct net_device *dev = skb->dev;
 596         struct frag_hdr *fhdr;
 597         struct nf_ct_frag6_queue *fq;
 598         struct ipv6hdr *hdr;
 599         int fhoff, nhoff;
 600         u8 prevhdr;
 601         struct sk_buff *ret_skb = NULL;
 602
 603         /* Jumbo payload inhibits frag. header */
 604         if (ipv6_hdr(skb)->payload_len == 0) {
 605                 pr_debug("payload len = 0\n");
 606                 return skb;
 607         }
 608
 609         if (find_prev_fhdr(skb, &prevhdr, &nhoff, &fhoff) < 0)
 610                 return skb;
 611
 612         clone = skb_clone(skb, GFP_ATOMIC);
 613         if (clone == NULL) {
 614                 pr_debug("Can't clone skb\n");
 615                 return skb;
 616         }
 617
 618         NFCT_FRAG6_CB(clone)->orig = skb;
 619
 620         if (!pskb_may_pull(clone, fhoff + sizeof(*fhdr))) {
 621                 pr_debug("message is too short.\n");
 622                 goto ret_orig;
 623         }
 624
 625         skb_set_transport_header(clone, fhoff);
 626         hdr = ipv6_hdr(clone);
 627         fhdr = (struct frag_hdr *)skb_transport_header(clone);
 628
 629         if (!(fhdr->frag_off & htons(0xFFF9))) {
 630                 pr_debug("Invalid fragment offset\n");
 631                 /* It is not a fragmented frame */
 632                 goto ret_orig;
 633         }
 634
 635         if (atomic_read(&nf_init_frags.mem) > nf_init_frags.high_thresh)
 636                 nf_ct_frag6_evictor();
 637
 638         fq = fq_find(fhdr->identification, &hdr->saddr, &hdr->daddr);
 639         if (fq == NULL) {
 640                 pr_debug("Can't find and can't create new queue\n");
 641                 goto ret_orig;
 642         }
 643
 644         spin_lock_bh(&fq->q.lock);
 645
 646         if (nf_ct_frag6_queue(fq, clone, fhdr, nhoff) < 0) {
 647                 spin_unlock_bh(&fq->q.lock);
 648                 pr_debug("Can't insert skb to queue\n");
 649                 fq_put(fq);
 650                 goto ret_orig;
 651         }
 652
 653         if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
 654             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_bh(&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_init(void)
 691 {
 692         nf_frags.hashfn = nf_hashfn;
 693         nf_frags.constructor = ip6_frag_init;
 694         nf_frags.destructor = NULL;
 695         nf_frags.skb_free = nf_skb_free;
 696         nf_frags.qsize = sizeof(struct nf_ct_frag6_queue);
 697         nf_frags.match = ip6_frag_match;
 698         nf_frags.frag_expire = nf_ct_frag6_expire;
 699         nf_frags.secret_interval = 10 * 60 * HZ;
 700         nf_init_frags.timeout = IPV6_FRAG_TIMEOUT;
 701         nf_init_frags.high_thresh = 256 * 1024;
 702         nf_init_frags.low_thresh = 192 * 1024;
 703         inet_frags_init_net(&nf_init_frags);
 704         inet_frags_init(&nf_frags);
 705
 706         return 0;
 707 }
 708
 709 void nf_ct_frag6_cleanup(void)
 710 {
 711         inet_frags_fini(&nf_frags);
 712
 713         nf_init_frags.low_thresh = 0;
 714         nf_ct_frag6_evictor();
 715 }