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
  30 #define pr_fmt(fmt) "IPv6: " fmt
  31
  32 #include <linux/errno.h>
  33 #include <linux/types.h>
  34 #include <linux/string.h>
  35 #include <linux/socket.h>
  36 #include <linux/sockios.h>
  37 #include <linux/jiffies.h>
  38 #include <linux/net.h>
  39 #include <linux/list.h>
  40 #include <linux/netdevice.h>
  41 #include <linux/in6.h>
  42 #include <linux/ipv6.h>
  43 #include <linux/icmpv6.h>
  44 #include <linux/random.h>
  45 #include <linux/jhash.h>
  46 #include <linux/skbuff.h>
  47 #include <linux/slab.h>
  48 #include <linux/export.h>
  49
  50 #include <net/sock.h>
  51 #include <net/snmp.h>
  52
  53 #include <net/ipv6.h>
  54 #include <net/ip6_route.h>
  55 #include <net/protocol.h>
  56 #include <net/transp_v6.h>
  57 #include <net/rawv6.h>
  58 #include <net/ndisc.h>
  59 #include <net/addrconf.h>
  60 #include <net/inet_frag.h>
  61
  62 struct ip6frag_skb_cb
  63 {
  64         struct inet6_skb_parm   h;
  65         int                     offset;
  66 };
  67
  68 #define FRAG6_CB(skb)   ((struct ip6frag_skb_cb*)((skb)->cb))
  69
  70
  71 /*
  72  *      Equivalent of ipv4 struct ipq
  73  */
  74
  75 struct frag_queue
  76 {
  77         struct inet_frag_queue  q;
  78
  79         __be32                  id;             /* fragment id          */
  80         u32                     user;
  81         struct in6_addr         saddr;
  82         struct in6_addr         daddr;
  83
  84         int                     iif;
  85         unsigned int            csum;
  86         __u16                   nhoffset;
  87 };
  88
  89 static struct inet_frags ip6_frags;
  90
  91 int ip6_frag_nqueues(struct net *net)
  92 {
  93         return net->ipv6.frags.nqueues;
  94 }
  95
  96 int ip6_frag_mem(struct net *net)
  97 {
  98         return atomic_read(&net->ipv6.frags.mem);
  99 }
 100
 101 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 102                           struct net_device *dev);
 103
 104 /*
 105  * callers should be careful not to use the hash value outside the ipfrag_lock
 106  * as doing so could race with ipfrag_hash_rnd being recalculated.
 107  */
 108 unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
 109                              const struct in6_addr *daddr, u32 rnd)
 110 {
 111         u32 c;
 112
 113         c = jhash_3words((__force u32)saddr->s6_addr32[0],
 114                          (__force u32)saddr->s6_addr32[1],
 115                          (__force u32)saddr->s6_addr32[2],
 116                          rnd);
 117
 118         c = jhash_3words((__force u32)saddr->s6_addr32[3],
 119                          (__force u32)daddr->s6_addr32[0],
 120                          (__force u32)daddr->s6_addr32[1],
 121                          c);
 122
 123         c =  jhash_3words((__force u32)daddr->s6_addr32[2],
 124                           (__force u32)daddr->s6_addr32[3],
 125                           (__force u32)id,
 126                           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, const struct in6_addr *src, const 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 (IS_ERR_OR_NULL(q)) {
 247                 inet_frag_maybe_warn_overflow(q, pr_fmt());
 248                 return NULL;
 249         }
 250         return container_of(q, struct frag_queue, q);
 251 }
 252
 253 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
 254                            struct frag_hdr *fhdr, int nhoff)
 255 {
 256         struct sk_buff *prev, *next;
 257         struct net_device *dev;
 258         int offset, end;
 259         struct net *net = dev_net(skb_dst(skb)->dev);
 260
 261         if (fq->q.last_in & INET_FRAG_COMPLETE)
 262                 goto err;
 263
 264         offset = ntohs(fhdr->frag_off) & ~0x7;
 265         end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
 266                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
 267
 268         if ((unsigned int)end > IPV6_MAXPLEN) {
 269                 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
 270                                  IPSTATS_MIB_INHDRERRORS);
 271                 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
 272                                   ((u8 *)&fhdr->frag_off -
 273                                    skb_network_header(skb)));
 274                 return -1;
 275         }
 276
 277         if (skb->ip_summed == CHECKSUM_COMPLETE) {
 278                 const unsigned char *nh = skb_network_header(skb);
 279                 skb->csum = csum_sub(skb->csum,
 280                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
 281                                                   0));
 282         }
 283
 284         /* Is this the final fragment? */
 285         if (!(fhdr->frag_off & htons(IP6_MF))) {
 286                 /* If we already have some bits beyond end
 287                  * or have different end, the segment is corrupted.
 288                  */
 289                 if (end < fq->q.len ||
 290                     ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len))
 291                         goto err;
 292                 fq->q.last_in |= INET_FRAG_LAST_IN;
 293                 fq->q.len = end;
 294         } else {
 295                 /* Check if the fragment is rounded to 8 bytes.
 296                  * Required by the RFC.
 297                  */
 298                 if (end & 0x7) {
 299                         /* RFC2460 says always send parameter problem in
 300                          * this case. -DaveM
 301                          */
 302                         IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
 303                                          IPSTATS_MIB_INHDRERRORS);
 304                         icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
 305                                           offsetof(struct ipv6hdr, payload_len));
 306                         return -1;
 307                 }
 308                 if (end > fq->q.len) {
 309                         /* Some bits beyond end -> corruption. */
 310                         if (fq->q.last_in & INET_FRAG_LAST_IN)
 311                                 goto err;
 312                         fq->q.len = end;
 313                 }
 314         }
 315
 316         if (end == offset)
 317                 goto err;
 318
 319         /* Point into the IP datagram 'data' part. */
 320         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
 321                 goto err;
 322
 323         if (pskb_trim_rcsum(skb, end - offset))
 324                 goto err;
 325
 326         /* Find out which fragments are in front and at the back of us
 327          * in the chain of fragments so far.  We must know where to put
 328          * this fragment, right?
 329          */
 330         prev = fq->q.fragments_tail;
 331         if (!prev || FRAG6_CB(prev)->offset < offset) {
 332                 next = NULL;
 333                 goto found;
 334         }
 335         prev = NULL;
 336         for(next = fq->q.fragments; next != NULL; next = next->next) {
 337                 if (FRAG6_CB(next)->offset >= offset)
 338                         break;  /* bingo! */
 339                 prev = next;
 340         }
 341
 342 found:
 343         /* RFC5722, Section 4:
 344          *                                  When reassembling an IPv6 datagram, if
 345          *   one or more its constituent fragments is determined to be an
 346          *   overlapping fragment, the entire datagram (and any constituent
 347          *   fragments, including those not yet received) MUST be silently
 348          *   discarded.
 349          */
 350
 351         /* Check for overlap with preceding fragment. */
 352         if (prev &&
 353             (FRAG6_CB(prev)->offset + prev->len) > offset)
 354                 goto discard_fq;
 355
 356         /* Look for overlap with succeeding segment. */
 357         if (next && FRAG6_CB(next)->offset < end)
 358                 goto discard_fq;
 359
 360         FRAG6_CB(skb)->offset = offset;
 361
 362         /* Insert this fragment in the chain of fragments. */
 363         skb->next = next;
 364         if (!next)
 365                 fq->q.fragments_tail = skb;
 366         if (prev)
 367                 prev->next = skb;
 368         else
 369                 fq->q.fragments = skb;
 370
 371         dev = skb->dev;
 372         if (dev) {
 373                 fq->iif = dev->ifindex;
 374                 skb->dev = NULL;
 375         }
 376         fq->q.stamp = skb->tstamp;
 377         fq->q.meat += skb->len;
 378         atomic_add(skb->truesize, &fq->q.net->mem);
 379
 380         /* The first fragment.
 381          * nhoffset is obtained from the first fragment, of course.
 382          */
 383         if (offset == 0) {
 384                 fq->nhoffset = nhoff;
 385                 fq->q.last_in |= INET_FRAG_FIRST_IN;
 386         }
 387
 388         if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
 389             fq->q.meat == fq->q.len) {
 390                 int res;
 391                 unsigned long orefdst = skb->_skb_refdst;
 392
 393                 skb->_skb_refdst = 0UL;
 394                 res = ip6_frag_reasm(fq, prev, dev);
 395                 skb->_skb_refdst = orefdst;
 396                 return res;
 397         }
 398
 399         skb_dst_drop(skb);
 400
 401         write_lock(&ip6_frags.lock);
 402         list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list);
 403         write_unlock(&ip6_frags.lock);
 404         return -1;
 405
 406 discard_fq:
 407         fq_kill(fq);
 408 err:
 409         IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
 410                       IPSTATS_MIB_REASMFAILS);
 411         kfree_skb(skb);
 412         return -1;
 413 }
 414
 415 /*
 416  *      Check if this packet is complete.
 417  *      Returns NULL on failure by any reason, and pointer
 418  *      to current nexthdr field in reassembled frame.
 419  *
 420  *      It is called with locked fq, and caller must check that
 421  *      queue is eligible for reassembly i.e. it is not COMPLETE,
 422  *      the last and the first frames arrived and all the bits are here.
 423  */
 424 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 425                           struct net_device *dev)
 426 {
 427         struct net *net = container_of(fq->q.net, struct net, ipv6.frags);
 428         struct sk_buff *fp, *head = fq->q.fragments;
 429         int    payload_len;
 430         unsigned int nhoff;
 431
 432         fq_kill(fq);
 433
 434         /* Make the one we just received the head. */
 435         if (prev) {
 436                 head = prev->next;
 437                 fp = skb_clone(head, GFP_ATOMIC);
 438
 439                 if (!fp)
 440                         goto out_oom;
 441
 442                 fp->next = head->next;
 443                 if (!fp->next)
 444                         fq->q.fragments_tail = fp;
 445                 prev->next = fp;
 446
 447                 skb_morph(head, fq->q.fragments);
 448                 head->next = fq->q.fragments->next;
 449
 450                 kfree_skb(fq->q.fragments);
 451                 fq->q.fragments = head;
 452         }
 453
 454         WARN_ON(head == NULL);
 455         WARN_ON(FRAG6_CB(head)->offset != 0);
 456
 457         /* Unfragmented part is taken from the first segment. */
 458         payload_len = ((head->data - skb_network_header(head)) -
 459                        sizeof(struct ipv6hdr) + fq->q.len -
 460                        sizeof(struct frag_hdr));
 461         if (payload_len > IPV6_MAXPLEN)
 462                 goto out_oversize;
 463
 464         /* Head of list must not be cloned. */
 465         if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
 466                 goto out_oom;
 467
 468         /* If the first fragment is fragmented itself, we split
 469          * it to two chunks: the first with data and paged part
 470          * and the second, holding only fragments. */
 471         if (skb_has_frag_list(head)) {
 472                 struct sk_buff *clone;
 473                 int i, plen = 0;
 474
 475                 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
 476                         goto out_oom;
 477                 clone->next = head->next;
 478                 head->next = clone;
 479                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
 480                 skb_frag_list_init(head);
 481                 for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
 482                         plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
 483                 clone->len = clone->data_len = head->data_len - plen;
 484                 head->data_len -= clone->len;
 485                 head->len -= clone->len;
 486                 clone->csum = 0;
 487                 clone->ip_summed = head->ip_summed;
 488                 atomic_add(clone->truesize, &fq->q.net->mem);
 489         }
 490
 491         /* We have to remove fragment header from datagram and to relocate
 492          * header in order to calculate ICV correctly. */
 493         nhoff = fq->nhoffset;
 494         skb_network_header(head)[nhoff] = skb_transport_header(head)[0];
 495         memmove(head->head + sizeof(struct frag_hdr), head->head,
 496                 (head->data - head->head) - sizeof(struct frag_hdr));
 497         head->mac_header += sizeof(struct frag_hdr);
 498         head->network_header += sizeof(struct frag_hdr);
 499
 500         skb_shinfo(head)->frag_list = head->next;
 501         skb_reset_transport_header(head);
 502         skb_push(head, head->data - skb_network_header(head));
 503
 504         for (fp=head->next; fp; fp = fp->next) {
 505                 head->data_len += fp->len;
 506                 head->len += fp->len;
 507                 if (head->ip_summed != fp->ip_summed)
 508                         head->ip_summed = CHECKSUM_NONE;
 509                 else if (head->ip_summed == CHECKSUM_COMPLETE)
 510                         head->csum = csum_add(head->csum, fp->csum);
 511                 head->truesize += fp->truesize;
 512         }
 513         atomic_sub(head->truesize, &fq->q.net->mem);
 514
 515         head->next = NULL;
 516         head->dev = dev;
 517         head->tstamp = fq->q.stamp;
 518         ipv6_hdr(head)->payload_len = htons(payload_len);
 519         IP6CB(head)->nhoff = nhoff;
 520         IP6CB(head)->flags |= IP6SKB_FRAGMENTED;
 521
 522         /* Yes, and fold redundant checksum back. 8) */
 523         if (head->ip_summed == CHECKSUM_COMPLETE)
 524                 head->csum = csum_partial(skb_network_header(head),
 525                                           skb_network_header_len(head),
 526                                           head->csum);
 527
 528         rcu_read_lock();
 529         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
 530         rcu_read_unlock();
 531         fq->q.fragments = NULL;
 532         fq->q.fragments_tail = NULL;
 533         return 1;
 534
 535 out_oversize:
 536         if (net_ratelimit())
 537                 printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len);
 538         goto out_fail;
 539 out_oom:
 540         if (net_ratelimit())
 541                 printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n");
 542 out_fail:
 543         rcu_read_lock();
 544         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
 545         rcu_read_unlock();
 546         return -1;
 547 }
 548
 549 static int ipv6_frag_rcv(struct sk_buff *skb)
 550 {
 551         struct frag_hdr *fhdr;
 552         struct frag_queue *fq;
 553         const struct ipv6hdr *hdr = ipv6_hdr(skb);
 554         struct net *net = dev_net(skb_dst(skb)->dev);
 555
 556         if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED)
 557                 goto fail_hdr;
 558
 559         IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS);
 560
 561         /* Jumbo payload inhibits frag. header */
 562         if (hdr->payload_len==0)
 563                 goto fail_hdr;
 564
 565         if (!pskb_may_pull(skb, (skb_transport_offset(skb) +
 566                                  sizeof(struct frag_hdr))))
 567                 goto fail_hdr;
 568
 569         hdr = ipv6_hdr(skb);
 570         fhdr = (struct frag_hdr *)skb_transport_header(skb);
 571
 572         if (!(fhdr->frag_off & htons(0xFFF9))) {
 573                 /* It is not a fragmented frame */
 574                 skb->transport_header += sizeof(struct frag_hdr);
 575                 IP6_INC_STATS_BH(net,
 576                                  ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS);
 577
 578                 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb);
 579                 IP6CB(skb)->flags |= IP6SKB_FRAGMENTED;
 580                 return 1;
 581         }
 582
 583         if (atomic_read(&net->ipv6.frags.mem) > net->ipv6.frags.high_thresh)
 584                 ip6_evictor(net, ip6_dst_idev(skb_dst(skb)));
 585
 586         fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr);
 587         if (fq != NULL) {
 588                 int ret;
 589
 590                 spin_lock(&fq->q.lock);
 591
 592                 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
 593
 594                 spin_unlock(&fq->q.lock);
 595                 fq_put(fq);
 596                 return ret;
 597         }
 598
 599         IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS);
 600         kfree_skb(skb);
 601         return -1;
 602
 603 fail_hdr:
 604         IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS);
 605         icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb));
 606         return -1;
 607 }
 608
 609 static const struct inet6_protocol frag_protocol =
 610 {
 611         .handler        =       ipv6_frag_rcv,
 612         .flags          =       INET6_PROTO_NOPOLICY,
 613 };
 614
 615 #ifdef CONFIG_SYSCTL
 616 static struct ctl_table ip6_frags_ns_ctl_table[] = {
 617         {
 618                 .procname       = "ip6frag_high_thresh",
 619                 .data           = &init_net.ipv6.frags.high_thresh,
 620                 .maxlen         = sizeof(int),
 621                 .mode           = 0644,
 622                 .proc_handler   = proc_dointvec
 623         },
 624         {
 625                 .procname       = "ip6frag_low_thresh",
 626                 .data           = &init_net.ipv6.frags.low_thresh,
 627                 .maxlen         = sizeof(int),
 628                 .mode           = 0644,
 629                 .proc_handler   = proc_dointvec
 630         },
 631         {
 632                 .procname       = "ip6frag_time",
 633                 .data           = &init_net.ipv6.frags.timeout,
 634                 .maxlen         = sizeof(int),
 635                 .mode           = 0644,
 636                 .proc_handler   = proc_dointvec_jiffies,
 637         },
 638         { }
 639 };
 640
 641 static struct ctl_table ip6_frags_ctl_table[] = {
 642         {
 643                 .procname       = "ip6frag_secret_interval",
 644                 .data           = &ip6_frags.secret_interval,
 645                 .maxlen         = sizeof(int),
 646                 .mode           = 0644,
 647                 .proc_handler   = proc_dointvec_jiffies,
 648         },
 649         { }
 650 };
 651
 652 static int __net_init ip6_frags_ns_sysctl_register(struct net *net)
 653 {
 654         struct ctl_table *table;
 655         struct ctl_table_header *hdr;
 656
 657         table = ip6_frags_ns_ctl_table;
 658         if (!net_eq(net, &init_net)) {
 659                 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL);
 660                 if (table == NULL)
 661                         goto err_alloc;
 662
 663                 table[0].data = &net->ipv6.frags.high_thresh;
 664                 table[1].data = &net->ipv6.frags.low_thresh;
 665                 table[2].data = &net->ipv6.frags.timeout;
 666         }
 667
 668         hdr = register_net_sysctl_table(net, net_ipv6_ctl_path, table);
 669         if (hdr == NULL)
 670                 goto err_reg;
 671
 672         net->ipv6.sysctl.frags_hdr = hdr;
 673         return 0;
 674
 675 err_reg:
 676         if (!net_eq(net, &init_net))
 677                 kfree(table);
 678 err_alloc:
 679         return -ENOMEM;
 680 }
 681
 682 static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net)
 683 {
 684         struct ctl_table *table;
 685
 686         table = net->ipv6.sysctl.frags_hdr->ctl_table_arg;
 687         unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr);
 688         if (!net_eq(net, &init_net))
 689                 kfree(table);
 690 }
 691
 692 static struct ctl_table_header *ip6_ctl_header;
 693
 694 static int ip6_frags_sysctl_register(void)
 695 {
 696         ip6_ctl_header = register_net_sysctl_rotable(net_ipv6_ctl_path,
 697                         ip6_frags_ctl_table);
 698         return ip6_ctl_header == NULL ? -ENOMEM : 0;
 699 }
 700
 701 static void ip6_frags_sysctl_unregister(void)
 702 {
 703         unregister_net_sysctl_table(ip6_ctl_header);
 704 }
 705 #else
 706 static inline int ip6_frags_ns_sysctl_register(struct net *net)
 707 {
 708         return 0;
 709 }
 710
 711 static inline void ip6_frags_ns_sysctl_unregister(struct net *net)
 712 {
 713 }
 714
 715 static inline int ip6_frags_sysctl_register(void)
 716 {
 717         return 0;
 718 }
 719
 720 static inline void ip6_frags_sysctl_unregister(void)
 721 {
 722 }
 723 #endif
 724
 725 static int __net_init ipv6_frags_init_net(struct net *net)
 726 {
 727         net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH;
 728         net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH;
 729         net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT;
 730
 731         inet_frags_init_net(&net->ipv6.frags);
 732
 733         return ip6_frags_ns_sysctl_register(net);
 734 }
 735
 736 static void __net_exit ipv6_frags_exit_net(struct net *net)
 737 {
 738         ip6_frags_ns_sysctl_unregister(net);
 739         inet_frags_exit_net(&net->ipv6.frags, &ip6_frags);
 740 }
 741
 742 static struct pernet_operations ip6_frags_ops = {
 743         .init = ipv6_frags_init_net,
 744         .exit = ipv6_frags_exit_net,
 745 };
 746
 747 int __init ipv6_frag_init(void)
 748 {
 749         int ret;
 750
 751         ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT);
 752         if (ret)
 753                 goto out;
 754
 755         ret = ip6_frags_sysctl_register();
 756         if (ret)
 757                 goto err_sysctl;
 758
 759         ret = register_pernet_subsys(&ip6_frags_ops);
 760         if (ret)
 761                 goto err_pernet;
 762
 763         ip6_frags.hashfn = ip6_hashfn;
 764         ip6_frags.constructor = ip6_frag_init;
 765         ip6_frags.destructor = NULL;
 766         ip6_frags.skb_free = NULL;
 767         ip6_frags.qsize = sizeof(struct frag_queue);
 768         ip6_frags.match = ip6_frag_match;
 769         ip6_frags.frag_expire = ip6_frag_expire;
 770         ip6_frags.secret_interval = 10 * 60 * HZ;
 771         inet_frags_init(&ip6_frags);
 772 out:
 773         return ret;
 774
 775 err_pernet:
 776         ip6_frags_sysctl_unregister();
 777 err_sysctl:
 778         inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
 779         goto out;
 780 }
 781
 782 void ipv6_frag_exit(void)
 783 {
 784         inet_frags_fini(&ip6_frags);
 785         ip6_frags_sysctl_unregister();
 786         unregister_pernet_subsys(&ip6_frags_ops);
 787         inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
 788 }