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