net/ipv6/reassembly.c

   1 /*
   2  *      IPv6 fragment reassembly
   3  *      Linux INET6 implementation
   4  *
   5  *      Authors:
   6  *      Pedro Roque             <roque@di.fc.ul.pt>
   7  *
   8  *      Based on: net/ipv4/ip_fragment.c
   9  *
  10  *      This program is free software; you can redistribute it and/or
  11  *      modify it under the terms of the GNU General Public License
  12  *      as published by the Free Software Foundation; either version
  13  *      2 of the License, or (at your option) any later version.
  14  */
  15
  16 /*
  17  *      Fixes:
  18  *      Andi Kleen      Make it work with multiple hosts.
  19  *                      More RFC compliance.
  20  *
  21  *      Horst von Brand Add missing #include <linux/string.h>
  22  *      Alexey Kuznetsov        SMP races, threading, cleanup.
  23  *      Patrick McHardy         LRU queue of frag heads for evictor.
  24  *      Mitsuru KANDA @USAGI    Register inet6_protocol{}.
  25  *      David Stevens and
  26  *      YOSHIFUJI,H. @USAGI     Always remove fragment header to
  27  *                              calculate ICV correctly.
  28  */
  29 #include <linux/errno.h>
  30 #include <linux/types.h>
  31 #include <linux/string.h>
  32 #include <linux/socket.h>
  33 #include <linux/sockios.h>
  34 #include <linux/jiffies.h>
  35 #include <linux/net.h>
  36 #include <linux/list.h>
  37 #include <linux/netdevice.h>
  38 #include <linux/in6.h>
  39 #include <linux/ipv6.h>
  40 #include <linux/icmpv6.h>
  41 #include <linux/random.h>
  42 #include <linux/jhash.h>
  43 #include <linux/skbuff.h>
  44 #include <linux/slab.h>
  45
  46 #include <net/sock.h>
  47 #include <net/snmp.h>
  48
  49 #include <net/ipv6.h>
  50 #include <net/ip6_route.h>
  51 #include <net/protocol.h>
  52 #include <net/transp_v6.h>
  53 #include <net/rawv6.h>
  54 #include <net/ndisc.h>
  55 #include <net/addrconf.h>
  56 #include <net/inet_frag.h>
  57
  58 struct ip6frag_skb_cb
  59 {
  60         struct inet6_skb_parm   h;
  61         int                     offset;
  62 };
  63
  64 #define FRAG6_CB(skb)   ((struct ip6frag_skb_cb*)((skb)->cb))
  65
  66
  67 /*
  68  *      Equivalent of ipv4 struct ipq
  69  */
  70
  71 struct frag_queue
  72 {
  73         struct inet_frag_queue  q;
  74
  75         __be32                  id;             /* fragment id          */
  76         u32                     user;
  77         struct in6_addr         saddr;
  78         struct in6_addr         daddr;
  79
  80         int                     iif;
  81         unsigned int            csum;
  82         __u16                   nhoffset;
  83 };
  84
  85 static struct inet_frags ip6_frags;
  86
  87 int ip6_frag_nqueues(struct net *net)
  88 {
  89         return net->ipv6.frags.nqueues;
  90 }
  91
  92 int ip6_frag_mem(struct net *net)
  93 {
  94         return atomic_read(&net->ipv6.frags.mem);
  95 }
  96
  97 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
  98                           struct net_device *dev);
  99
 100 /*
 101  * callers should be careful not to use the hash value outside the ipfrag_lock
 102  * as doing so could race with ipfrag_hash_rnd being recalculated.
 103  */
 104 unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
 105                              const struct in6_addr *daddr, u32 rnd)
 106 {
 107         u32 a, b, c;
 108
 109         a = (__force u32)saddr->s6_addr32[0];
 110         b = (__force u32)saddr->s6_addr32[1];
 111         c = (__force u32)saddr->s6_addr32[2];
 112
 113         a += JHASH_GOLDEN_RATIO;
 114         b += JHASH_GOLDEN_RATIO;
 115         c += rnd;
 116         __jhash_mix(a, b, c);
 117
 118         a += (__force u32)saddr->s6_addr32[3];
 119         b += (__force u32)daddr->s6_addr32[0];
 120         c += (__force u32)daddr->s6_addr32[1];
 121         __jhash_mix(a, b, c);
 122
 123         a += (__force u32)daddr->s6_addr32[2];
 124         b += (__force u32)daddr->s6_addr32[3];
 125         c += (__force u32)id;
 126         __jhash_mix(a, b, c);
 127
 128         return c & (INETFRAGS_HASHSZ - 1);
 129 }
 130 EXPORT_SYMBOL_GPL(inet6_hash_frag);
 131
 132 static unsigned int ip6_hashfn(struct inet_frag_queue *q)
 133 {
 134         struct frag_queue *fq;
 135
 136         fq = container_of(q, struct frag_queue, q);
 137         return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr, ip6_frags.rnd);
 138 }
 139
 140 int ip6_frag_match(struct inet_frag_queue *q, void *a)
 141 {
 142         struct frag_queue *fq;
 143         struct ip6_create_arg *arg = a;
 144
 145         fq = container_of(q, struct frag_queue, q);
 146         return (fq->id == arg->id && fq->user == arg->user &&
 147                         ipv6_addr_equal(&fq->saddr, arg->src) &&
 148                         ipv6_addr_equal(&fq->daddr, arg->dst));
 149 }
 150 EXPORT_SYMBOL(ip6_frag_match);
 151
 152 void ip6_frag_init(struct inet_frag_queue *q, void *a)
 153 {
 154         struct frag_queue *fq = container_of(q, struct frag_queue, q);
 155         struct ip6_create_arg *arg = a;
 156
 157         fq->id = arg->id;
 158         fq->user = arg->user;
 159         ipv6_addr_copy(&fq->saddr, arg->src);
 160         ipv6_addr_copy(&fq->daddr, arg->dst);
 161 }
 162 EXPORT_SYMBOL(ip6_frag_init);
 163
 164 /* Destruction primitives. */
 165
 166 static __inline__ void fq_put(struct frag_queue *fq)
 167 {
 168         inet_frag_put(&fq->q, &ip6_frags);
 169 }
 170
 171 /* Kill fq entry. It is not destroyed immediately,
 172  * because caller (and someone more) holds reference count.
 173  */
 174 static __inline__ void fq_kill(struct frag_queue *fq)
 175 {
 176         inet_frag_kill(&fq->q, &ip6_frags);
 177 }
 178
 179 static void ip6_evictor(struct net *net, struct inet6_dev *idev)
 180 {
 181         int evicted;
 182
 183         evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags);
 184         if (evicted)
 185                 IP6_ADD_STATS_BH(net, idev, IPSTATS_MIB_REASMFAILS, evicted);
 186 }
 187
 188 static void ip6_frag_expire(unsigned long data)
 189 {
 190         struct frag_queue *fq;
 191         struct net_device *dev = NULL;
 192         struct net *net;
 193
 194         fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
 195
 196         spin_lock(&fq->q.lock);
 197
 198         if (fq->q.last_in & INET_FRAG_COMPLETE)
 199                 goto out;
 200
 201         fq_kill(fq);
 202
 203         net = container_of(fq->q.net, struct net, ipv6.frags);
 204         rcu_read_lock();
 205         dev = dev_get_by_index_rcu(net, fq->iif);
 206         if (!dev)
 207                 goto out_rcu_unlock;
 208
 209         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
 210         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
 211
 212         /* Don't send error if the first segment did not arrive. */
 213         if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments)
 214                 goto out_rcu_unlock;
 215
 216         /*
 217            But use as source device on which LAST ARRIVED
 218            segment was received. And do not use fq->dev
 219            pointer directly, device might already disappeared.
 220          */
 221         fq->q.fragments->dev = dev;
 222         icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
 223 out_rcu_unlock:
 224         rcu_read_unlock();
 225 out:
 226         spin_unlock(&fq->q.lock);
 227         fq_put(fq);
 228 }
 229
 230 static __inline__ struct frag_queue *
 231 fq_find(struct net *net, __be32 id, struct in6_addr *src, struct in6_addr *dst)
 232 {
 233         struct inet_frag_queue *q;
 234         struct ip6_create_arg arg;
 235         unsigned int hash;
 236
 237         arg.id = id;
 238         arg.user = IP6_DEFRAG_LOCAL_DELIVER;
 239         arg.src = src;
 240         arg.dst = dst;
 241
 242         read_lock(&ip6_frags.lock);
 243         hash = inet6_hash_frag(id, src, dst, ip6_frags.rnd);
 244
 245         q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash);
 246         if (q == NULL)
 247                 return NULL;
 248
 249         return container_of(q, struct frag_queue, q);
 250 }
 251
 252 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
 253                            struct frag_hdr *fhdr, int nhoff)
 254 {
 255         struct sk_buff *prev, *next;
 256         struct net_device *dev;
 257         int offset, end;
 258         struct net *net = dev_net(skb_dst(skb)->dev);
 259
 260         if (fq->q.last_in & INET_FRAG_COMPLETE)
 261                 goto err;
 262
 263         offset = ntohs(fhdr->frag_off) & ~0x7;
 264         end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
 265                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
 266
 267         if ((unsigned int)end > IPV6_MAXPLEN) {
 268                 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
 269                                  IPSTATS_MIB_INHDRERRORS);
 270                 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
 271                                   ((u8 *)&fhdr->frag_off -
 272                                    skb_network_header(skb)));
 273                 return -1;
 274         }
 275
 276         if (skb->ip_summed == CHECKSUM_COMPLETE) {
 277                 const unsigned char *nh = skb_network_header(skb);
 278                 skb->csum = csum_sub(skb->csum,
 279                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
 280                                                   0));
 281         }
 282
 283         /* Is this the final fragment? */
 284         if (!(fhdr->frag_off & htons(IP6_MF))) {
 285                 /* If we already have some bits beyond end
 286                  * or have different end, the segment is corrupted.
 287                  */
 288                 if (end < fq->q.len ||
 289                     ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len))
 290                         goto err;
 291                 fq->q.last_in |= INET_FRAG_LAST_IN;
 292                 fq->q.len = end;
 293         } else {
 294                 /* Check if the fragment is rounded to 8 bytes.
 295                  * Required by the RFC.
 296                  */
 297                 if (end & 0x7) {
 298                         /* RFC2460 says always send parameter problem in
 299                          * this case. -DaveM
 300                          */
 301                         IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
 302                                          IPSTATS_MIB_INHDRERRORS);
 303                         icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
 304                                           offsetof(struct ipv6hdr, payload_len));
 305                         return -1;
 306                 }
 307                 if (end > fq->q.len) {
 308                         /* Some bits beyond end -> corruption. */
 309                         if (fq->q.last_in & INET_FRAG_LAST_IN)
 310                                 goto err;
 311                         fq->q.len = end;
 312                 }
 313         }
 314
 315         if (end == offset)
 316                 goto err;
 317
 318         /* Point into the IP datagram 'data' part. */
 319         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
 320                 goto err;
 321
 322         if (pskb_trim_rcsum(skb, end - offset))
 323                 goto err;
 324
 325         /* Find out which fragments are in front and at the back of us
 326          * in the chain of fragments so far.  We must know where to put
 327          * this fragment, right?
 328          */
 329         prev = fq->q.fragments_tail;
 330         if (!prev || FRAG6_CB(prev)->offset < offset) {
 331                 next = NULL;
 332                 goto found;
 333         }
 334         prev = NULL;
 335         for(next = fq->q.fragments; next != NULL; next = next->next) {
 336                 if (FRAG6_CB(next)->offset >= offset)
 337                         break;  /* bingo! */
 338                 prev = next;
 339         }
 340
 341 found:
 342         /* RFC5722, Section 4:
 343          *                                  When reassembling an IPv6 datagram, if
 344          *   one or more its constituent fragments is determined to be an
 345          *   overlapping fragment, the entire datagram (and any constituent
 346          *   fragments, including those not yet received) MUST be silently
 347          *   discarded.
 348          */
 349
 350         /* Check for overlap with preceding fragment. */
 351         if (prev &&
 352             (FRAG6_CB(prev)->offset + prev->len) > offset)
 353                 goto discard_fq;
 354
 355         /* Look for overlap with succeeding segment. */
 356         if (next && FRAG6_CB(next)->offset < end)
 357                 goto discard_fq;
 358
 359         FRAG6_CB(skb)->offset = offset;
 360
 361         /* Insert this fragment in the chain of fragments. */
 362         skb->next = next;
 363         if (!next)
 364                 fq->q.fragments_tail = skb;
 365         if (prev)
 366                 prev->next = skb;
 367         else
 368                 fq->q.fragments = skb;
 369
 370         dev = skb->dev;
 371         if (dev) {
 372                 fq->iif = dev->ifindex;
 373                 skb->dev = NULL;
 374         }
 375         fq->q.stamp = skb->tstamp;
 376         fq->q.meat += skb->len;
 377         atomic_add(skb->truesize, &fq->q.net->mem);
 378
 379         /* The first fragment.
 380          * nhoffset is obtained from the first fragment, of course.
 381          */
 382         if (offset == 0) {
 383                 fq->nhoffset = nhoff;
 384                 fq->q.last_in |= INET_FRAG_FIRST_IN;
 385         }
 386
 387         if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
 388             fq->q.meat == fq->q.len)
 389                 return ip6_frag_reasm(fq, prev, dev);
 390
 391         write_lock(&ip6_frags.lock);
 392         list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list);
 393         write_unlock(&ip6_frags.lock);
 394         return -1;
 395
 396 discard_fq:
 397         fq_kill(fq);
 398 err:
 399         IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
 400                       IPSTATS_MIB_REASMFAILS);
 401         kfree_skb(skb);
 402         return -1;
 403 }
 404
 405 /*
 406  *      Check if this packet is complete.
 407  *      Returns NULL on failure by any reason, and pointer
 408  *      to current nexthdr field in reassembled frame.
 409  *
 410  *      It is called with locked fq, and caller must check that
 411  *      queue is eligible for reassembly i.e. it is not COMPLETE,
 412  *      the last and the first frames arrived and all the bits are here.
 413  */
 414 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 415                           struct net_device *dev)
 416 {
 417         struct net *net = container_of(fq->q.net, struct net, ipv6.frags);
 418         struct sk_buff *fp, *head = fq->q.fragments;
 419         int    payload_len;
 420         unsigned int nhoff;
 421
 422         fq_kill(fq);
 423
 424         /* Make the one we just received the head. */
 425         if (prev) {
 426                 head = prev->next;
 427                 fp = skb_clone(head, GFP_ATOMIC);
 428
 429                 if (!fp)
 430                         goto out_oom;
 431
 432                 fp->next = head->next;
 433                 if (!fp->next)
 434                         fq->q.fragments_tail = fp;
 435                 prev->next = fp;
 436
 437                 skb_morph(head, fq->q.fragments);
 438                 head->next = fq->q.fragments->next;
 439
 440                 kfree_skb(fq->q.fragments);
 441                 fq->q.fragments = head;
 442         }
 443
 444         WARN_ON(head == NULL);
 445         WARN_ON(FRAG6_CB(head)->offset != 0);
 446
 447         /* Unfragmented part is taken from the first segment. */
 448         payload_len = ((head->data - skb_network_header(head)) -
 449                        sizeof(struct ipv6hdr) + fq->q.len -
 450                        sizeof(struct frag_hdr));
 451         if (payload_len > IPV6_MAXPLEN)
 452                 goto out_oversize;
 453
 454         /* Head of list must not be cloned. */
 455         if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
 456                 goto out_oom;
 457
 458         /* If the first fragment is fragmented itself, we split
 459          * it to two chunks: the first with data and paged part
 460          * and the second, holding only fragments. */
 461         if (skb_has_frag_list(head)) {
 462                 struct sk_buff *clone;
 463                 int i, plen = 0;
 464
 465                 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
 466                         goto out_oom;
 467                 clone->next = head->next;
 468                 head->next = clone;
 469                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
 470                 skb_frag_list_init(head);
 471                 for (i=0; i<skb_shinfo(head)->nr_frags; i++)
 472                         plen += skb_shinfo(head)->frags[i].size;
 473                 clone->len = clone->data_len = head->data_len - plen;
 474                 head->data_len -= clone->len;
 475                 head->len -= clone->len;
 476                 clone->csum = 0;
 477                 clone->ip_summed = head->ip_summed;
 478                 atomic_add(clone->truesize, &fq->q.net->mem);
 479         }
 480
 481         /* We have to remove fragment header from datagram and to relocate
 482          * header in order to calculate ICV correctly. */
 483         nhoff = fq->nhoffset;
 484         skb_network_header(head)[nhoff] = skb_transport_header(head)[0];
 485         memmove(head->head + sizeof(struct frag_hdr), head->head,
 486                 (head->data - head->head) - sizeof(struct frag_hdr));
 487         head->mac_header += sizeof(struct frag_hdr);
 488         head->network_header += sizeof(struct frag_hdr);
 489
 490         skb_shinfo(head)->frag_list = head->next;
 491         skb_reset_transport_header(head);
 492         skb_push(head, head->data - skb_network_header(head));
 493
 494         for (fp=head->next; fp; fp = fp->next) {
 495                 head->data_len += fp->len;
 496                 head->len += fp->len;
 497                 if (head->ip_summed != fp->ip_summed)
 498                         head->ip_summed = CHECKSUM_NONE;
 499                 else if (head->ip_summed == CHECKSUM_COMPLETE)
 500                         head->csum = csum_add(head->csum, fp->csum);
 501                 head->truesize += fp->truesize;
 502         }
 503         atomic_sub(head->truesize, &fq->q.net->mem);
 504
 505         head->next = NULL;
 506         head->dev = dev;
 507         head->tstamp = fq->q.stamp;
 508         ipv6_hdr(head)->payload_len = htons(payload_len);
 509         IP6CB(head)->nhoff = nhoff;
 510
 511         /* Yes, and fold redundant checksum back. 8) */
 512         if (head->ip_summed == CHECKSUM_COMPLETE)
 513                 head->csum = csum_partial(skb_network_header(head),
 514                                           skb_network_header_len(head),
 515                                           head->csum);
 516
 517         rcu_read_lock();
 518         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
 519         rcu_read_unlock();
 520         fq->q.fragments = NULL;
 521         fq->q.fragments_tail = NULL;
 522         return 1;
 523
 524 out_oversize:
 525         if (net_ratelimit())
 526                 printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len);
 527         goto out_fail;
 528 out_oom:
 529         if (net_ratelimit())
 530                 printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n");
 531 out_fail:
 532         rcu_read_lock();
 533         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
 534         rcu_read_unlock();
 535         return -1;
 536 }
 537
 538 static int ipv6_frag_rcv(struct sk_buff *skb)
 539 {
 540         struct frag_hdr *fhdr;
 541         struct frag_queue *fq;
 542         struct ipv6hdr *hdr = ipv6_hdr(skb);
 543         struct net *net = dev_net(skb_dst(skb)->dev);
 544
 545         IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS);
 546
 547         /* Jumbo payload inhibits frag. header */
 548         if (hdr->payload_len==0)
 549                 goto fail_hdr;
 550
 551         if (!pskb_may_pull(skb, (skb_transport_offset(skb) +
 552                                  sizeof(struct frag_hdr))))
 553                 goto fail_hdr;
 554
 555         hdr = ipv6_hdr(skb);
 556         fhdr = (struct frag_hdr *)skb_transport_header(skb);
 557
 558         if (!(fhdr->frag_off & htons(0xFFF9))) {
 559                 /* It is not a fragmented frame */
 560                 skb->transport_header += sizeof(struct frag_hdr);
 561                 IP6_INC_STATS_BH(net,
 562                                  ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS);
 563
 564                 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb);
 565                 return 1;
 566         }
 567
 568         if (atomic_read(&net->ipv6.frags.mem) > net->ipv6.frags.high_thresh)
 569                 ip6_evictor(net, ip6_dst_idev(skb_dst(skb)));
 570
 571         fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr);
 572         if (fq != NULL) {
 573                 int ret;
 574
 575                 spin_lock(&fq->q.lock);
 576
 577                 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
 578
 579                 spin_unlock(&fq->q.lock);
 580                 fq_put(fq);
 581                 return ret;
 582         }
 583
 584         IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS);
 585         kfree_skb(skb);
 586         return -1;
 587
 588 fail_hdr:
 589         IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS);
 590         icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb));
 591         return -1;
 592 }
 593
 594 static const struct inet6_protocol frag_protocol =
 595 {
 596         .handler        =       ipv6_frag_rcv,
 597         .flags          =       INET6_PROTO_NOPOLICY,
 598 };
 599
 600 #ifdef CONFIG_SYSCTL
 601 static struct ctl_table ip6_frags_ns_ctl_table[] = {
 602         {
 603                 .procname       = "ip6frag_high_thresh",
 604                 .data           = &init_net.ipv6.frags.high_thresh,
 605                 .maxlen         = sizeof(int),
 606                 .mode           = 0644,
 607                 .proc_handler   = proc_dointvec
 608         },
 609         {
 610                 .procname       = "ip6frag_low_thresh",
 611                 .data           = &init_net.ipv6.frags.low_thresh,
 612                 .maxlen         = sizeof(int),
 613                 .mode           = 0644,
 614                 .proc_handler   = proc_dointvec
 615         },
 616         {
 617                 .procname       = "ip6frag_time",
 618                 .data           = &init_net.ipv6.frags.timeout,
 619                 .maxlen         = sizeof(int),
 620                 .mode           = 0644,
 621                 .proc_handler   = proc_dointvec_jiffies,
 622         },
 623         { }
 624 };
 625
 626 static struct ctl_table ip6_frags_ctl_table[] = {
 627         {
 628                 .procname       = "ip6frag_secret_interval",
 629                 .data           = &ip6_frags.secret_interval,
 630                 .maxlen         = sizeof(int),
 631                 .mode           = 0644,
 632                 .proc_handler   = proc_dointvec_jiffies,
 633         },
 634         { }
 635 };
 636
 637 static int __net_init ip6_frags_ns_sysctl_register(struct net *net)
 638 {
 639         struct ctl_table *table;
 640         struct ctl_table_header *hdr;
 641
 642         table = ip6_frags_ns_ctl_table;
 643         if (!net_eq(net, &init_net)) {
 644                 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL);
 645                 if (table == NULL)
 646                         goto err_alloc;
 647
 648                 table[0].data = &net->ipv6.frags.high_thresh;
 649                 table[1].data = &net->ipv6.frags.low_thresh;
 650                 table[2].data = &net->ipv6.frags.timeout;
 651         }
 652
 653         hdr = register_net_sysctl_table(net, net_ipv6_ctl_path, table);
 654         if (hdr == NULL)
 655                 goto err_reg;
 656
 657         net->ipv6.sysctl.frags_hdr = hdr;
 658         return 0;
 659
 660 err_reg:
 661         if (!net_eq(net, &init_net))
 662                 kfree(table);
 663 err_alloc:
 664         return -ENOMEM;
 665 }
 666
 667 static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net)
 668 {
 669         struct ctl_table *table;
 670
 671         table = net->ipv6.sysctl.frags_hdr->ctl_table_arg;
 672         unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr);
 673         if (!net_eq(net, &init_net))
 674                 kfree(table);
 675 }
 676
 677 static struct ctl_table_header *ip6_ctl_header;
 678
 679 static int ip6_frags_sysctl_register(void)
 680 {
 681         ip6_ctl_header = register_net_sysctl_rotable(net_ipv6_ctl_path,
 682                         ip6_frags_ctl_table);
 683         return ip6_ctl_header == NULL ? -ENOMEM : 0;
 684 }
 685
 686 static void ip6_frags_sysctl_unregister(void)
 687 {
 688         unregister_net_sysctl_table(ip6_ctl_header);
 689 }
 690 #else
 691 static inline int ip6_frags_ns_sysctl_register(struct net *net)
 692 {
 693         return 0;
 694 }
 695
 696 static inline void ip6_frags_ns_sysctl_unregister(struct net *net)
 697 {
 698 }
 699
 700 static inline int ip6_frags_sysctl_register(void)
 701 {
 702         return 0;
 703 }
 704
 705 static inline void ip6_frags_sysctl_unregister(void)
 706 {
 707 }
 708 #endif
 709
 710 static int __net_init ipv6_frags_init_net(struct net *net)
 711 {
 712         net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH;
 713         net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH;
 714         net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT;
 715
 716         inet_frags_init_net(&net->ipv6.frags);
 717
 718         return ip6_frags_ns_sysctl_register(net);
 719 }
 720
 721 static void __net_exit ipv6_frags_exit_net(struct net *net)
 722 {
 723         ip6_frags_ns_sysctl_unregister(net);
 724         inet_frags_exit_net(&net->ipv6.frags, &ip6_frags);
 725 }
 726
 727 static struct pernet_operations ip6_frags_ops = {
 728         .init = ipv6_frags_init_net,
 729         .exit = ipv6_frags_exit_net,
 730 };
 731
 732 int __init ipv6_frag_init(void)
 733 {
 734         int ret;
 735
 736         ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT);
 737         if (ret)
 738                 goto out;
 739
 740         ret = ip6_frags_sysctl_register();
 741         if (ret)
 742                 goto err_sysctl;
 743
 744         ret = register_pernet_subsys(&ip6_frags_ops);
 745         if (ret)
 746                 goto err_pernet;
 747
 748         ip6_frags.hashfn = ip6_hashfn;
 749         ip6_frags.constructor = ip6_frag_init;
 750         ip6_frags.destructor = NULL;
 751         ip6_frags.skb_free = NULL;
 752         ip6_frags.qsize = sizeof(struct frag_queue);
 753         ip6_frags.match = ip6_frag_match;
 754         ip6_frags.frag_expire = ip6_frag_expire;
 755         ip6_frags.secret_interval = 10 * 60 * HZ;
 756         inet_frags_init(&ip6_frags);
 757 out:
 758         return ret;
 759
 760 err_pernet:
 761         ip6_frags_sysctl_unregister();
 762 err_sysctl:
 763         inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
 764         goto out;
 765 }
 766
 767 void ipv6_frag_exit(void)
 768 {
 769         inet_frags_fini(&ip6_frags);
 770         ip6_frags_sysctl_unregister();
 771         unregister_pernet_subsys(&ip6_frags_ops);
 772         inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
 773 }