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 /* Memory Tracking Functions. */
 153 static void frag_kfree_skb(struct netns_frags *nf, struct sk_buff *skb)
 154 {
 155         atomic_sub(skb->truesize, &nf->mem);
 156         kfree_skb(skb);
 157 }
 158
 159 void ip6_frag_init(struct inet_frag_queue *q, void *a)
 160 {
 161         struct frag_queue *fq = container_of(q, struct frag_queue, q);
 162         struct ip6_create_arg *arg = a;
 163
 164         fq->id = arg->id;
 165         fq->user = arg->user;
 166         ipv6_addr_copy(&fq->saddr, arg->src);
 167         ipv6_addr_copy(&fq->daddr, arg->dst);
 168 }
 169 EXPORT_SYMBOL(ip6_frag_init);
 170
 171 /* Destruction primitives. */
 172
 173 static __inline__ void fq_put(struct frag_queue *fq)
 174 {
 175         inet_frag_put(&fq->q, &ip6_frags);
 176 }
 177
 178 /* Kill fq entry. It is not destroyed immediately,
 179  * because caller (and someone more) holds reference count.
 180  */
 181 static __inline__ void fq_kill(struct frag_queue *fq)
 182 {
 183         inet_frag_kill(&fq->q, &ip6_frags);
 184 }
 185
 186 static void ip6_evictor(struct net *net, struct inet6_dev *idev)
 187 {
 188         int evicted;
 189
 190         evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags);
 191         if (evicted)
 192                 IP6_ADD_STATS_BH(net, idev, IPSTATS_MIB_REASMFAILS, evicted);
 193 }
 194
 195 static void ip6_frag_expire(unsigned long data)
 196 {
 197         struct frag_queue *fq;
 198         struct net_device *dev = NULL;
 199         struct net *net;
 200
 201         fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
 202
 203         spin_lock(&fq->q.lock);
 204
 205         if (fq->q.last_in & INET_FRAG_COMPLETE)
 206                 goto out;
 207
 208         fq_kill(fq);
 209
 210         net = container_of(fq->q.net, struct net, ipv6.frags);
 211         rcu_read_lock();
 212         dev = dev_get_by_index_rcu(net, fq->iif);
 213         if (!dev)
 214                 goto out_rcu_unlock;
 215
 216         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
 217         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
 218
 219         /* Don't send error if the first segment did not arrive. */
 220         if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments)
 221                 goto out_rcu_unlock;
 222
 223         /*
 224            But use as source device on which LAST ARRIVED
 225            segment was received. And do not use fq->dev
 226            pointer directly, device might already disappeared.
 227          */
 228         fq->q.fragments->dev = dev;
 229         icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
 230 out_rcu_unlock:
 231         rcu_read_unlock();
 232 out:
 233         spin_unlock(&fq->q.lock);
 234         fq_put(fq);
 235 }
 236
 237 static __inline__ struct frag_queue *
 238 fq_find(struct net *net, __be32 id, struct in6_addr *src, struct in6_addr *dst)
 239 {
 240         struct inet_frag_queue *q;
 241         struct ip6_create_arg arg;
 242         unsigned int hash;
 243
 244         arg.id = id;
 245         arg.user = IP6_DEFRAG_LOCAL_DELIVER;
 246         arg.src = src;
 247         arg.dst = dst;
 248
 249         read_lock(&ip6_frags.lock);
 250         hash = inet6_hash_frag(id, src, dst, ip6_frags.rnd);
 251
 252         q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash);
 253         if (q == NULL)
 254                 return NULL;
 255
 256         return container_of(q, struct frag_queue, q);
 257 }
 258
 259 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
 260                            struct frag_hdr *fhdr, int nhoff)
 261 {
 262         struct sk_buff *prev, *next;
 263         struct net_device *dev;
 264         int offset, end;
 265         struct net *net = dev_net(skb_dst(skb)->dev);
 266
 267         if (fq->q.last_in & INET_FRAG_COMPLETE)
 268                 goto err;
 269
 270         offset = ntohs(fhdr->frag_off) & ~0x7;
 271         end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
 272                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
 273
 274         if ((unsigned int)end > IPV6_MAXPLEN) {
 275                 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
 276                                  IPSTATS_MIB_INHDRERRORS);
 277                 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
 278                                   ((u8 *)&fhdr->frag_off -
 279                                    skb_network_header(skb)));
 280                 return -1;
 281         }
 282
 283         if (skb->ip_summed == CHECKSUM_COMPLETE) {
 284                 const unsigned char *nh = skb_network_header(skb);
 285                 skb->csum = csum_sub(skb->csum,
 286                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
 287                                                   0));
 288         }
 289
 290         /* Is this the final fragment? */
 291         if (!(fhdr->frag_off & htons(IP6_MF))) {
 292                 /* If we already have some bits beyond end
 293                  * or have different end, the segment is corrupted.
 294                  */
 295                 if (end < fq->q.len ||
 296                     ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len))
 297                         goto err;
 298                 fq->q.last_in |= INET_FRAG_LAST_IN;
 299                 fq->q.len = end;
 300         } else {
 301                 /* Check if the fragment is rounded to 8 bytes.
 302                  * Required by the RFC.
 303                  */
 304                 if (end & 0x7) {
 305                         /* RFC2460 says always send parameter problem in
 306                          * this case. -DaveM
 307                          */
 308                         IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
 309                                          IPSTATS_MIB_INHDRERRORS);
 310                         icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
 311                                           offsetof(struct ipv6hdr, payload_len));
 312                         return -1;
 313                 }
 314                 if (end > fq->q.len) {
 315                         /* Some bits beyond end -> corruption. */
 316                         if (fq->q.last_in & INET_FRAG_LAST_IN)
 317                                 goto err;
 318                         fq->q.len = end;
 319                 }
 320         }
 321
 322         if (end == offset)
 323                 goto err;
 324
 325         /* Point into the IP datagram 'data' part. */
 326         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
 327                 goto err;
 328
 329         if (pskb_trim_rcsum(skb, end - offset))
 330                 goto err;
 331
 332         /* Find out which fragments are in front and at the back of us
 333          * in the chain of fragments so far.  We must know where to put
 334          * this fragment, right?
 335          */
 336         prev = NULL;
 337         for(next = fq->q.fragments; next != NULL; next = next->next) {
 338                 if (FRAG6_CB(next)->offset >= offset)
 339                         break;  /* bingo! */
 340                 prev = next;
 341         }
 342
 343         /* We found where to put this one.  Check for overlap with
 344          * preceding fragment, and, if needed, align things so that
 345          * any overlaps are eliminated.
 346          */
 347         if (prev) {
 348                 int i = (FRAG6_CB(prev)->offset + prev->len) - offset;
 349
 350                 if (i > 0) {
 351                         offset += i;
 352                         if (end <= offset)
 353                                 goto err;
 354                         if (!pskb_pull(skb, i))
 355                                 goto err;
 356                         if (skb->ip_summed != CHECKSUM_UNNECESSARY)
 357                                 skb->ip_summed = CHECKSUM_NONE;
 358                 }
 359         }
 360
 361         /* Look for overlap with succeeding segments.
 362          * If we can merge fragments, do it.
 363          */
 364         while (next && FRAG6_CB(next)->offset < end) {
 365                 int i = end - FRAG6_CB(next)->offset; /* overlap is 'i' bytes */
 366
 367                 if (i < next->len) {
 368                         /* Eat head of the next overlapped fragment
 369                          * and leave the loop. The next ones cannot overlap.
 370                          */
 371                         if (!pskb_pull(next, i))
 372                                 goto err;
 373                         FRAG6_CB(next)->offset += i;    /* next fragment */
 374                         fq->q.meat -= i;
 375                         if (next->ip_summed != CHECKSUM_UNNECESSARY)
 376                                 next->ip_summed = CHECKSUM_NONE;
 377                         break;
 378                 } else {
 379                         struct sk_buff *free_it = next;
 380
 381                         /* Old fragment is completely overridden with
 382                          * new one drop it.
 383                          */
 384                         next = next->next;
 385
 386                         if (prev)
 387                                 prev->next = next;
 388                         else
 389                                 fq->q.fragments = next;
 390
 391                         fq->q.meat -= free_it->len;
 392                         frag_kfree_skb(fq->q.net, free_it);
 393                 }
 394         }
 395
 396         FRAG6_CB(skb)->offset = offset;
 397
 398         /* Insert this fragment in the chain of fragments. */
 399         skb->next = next;
 400         if (prev)
 401                 prev->next = skb;
 402         else
 403                 fq->q.fragments = skb;
 404
 405         dev = skb->dev;
 406         if (dev) {
 407                 fq->iif = dev->ifindex;
 408                 skb->dev = NULL;
 409         }
 410         fq->q.stamp = skb->tstamp;
 411         fq->q.meat += skb->len;
 412         atomic_add(skb->truesize, &fq->q.net->mem);
 413
 414         /* The first fragment.
 415          * nhoffset is obtained from the first fragment, of course.
 416          */
 417         if (offset == 0) {
 418                 fq->nhoffset = nhoff;
 419                 fq->q.last_in |= INET_FRAG_FIRST_IN;
 420         }
 421
 422         if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
 423             fq->q.meat == fq->q.len)
 424                 return ip6_frag_reasm(fq, prev, dev);
 425
 426         write_lock(&ip6_frags.lock);
 427         list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list);
 428         write_unlock(&ip6_frags.lock);
 429         return -1;
 430
 431 err:
 432         IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
 433                       IPSTATS_MIB_REASMFAILS);
 434         kfree_skb(skb);
 435         return -1;
 436 }
 437
 438 /*
 439  *      Check if this packet is complete.
 440  *      Returns NULL on failure by any reason, and pointer
 441  *      to current nexthdr field in reassembled frame.
 442  *
 443  *      It is called with locked fq, and caller must check that
 444  *      queue is eligible for reassembly i.e. it is not COMPLETE,
 445  *      the last and the first frames arrived and all the bits are here.
 446  */
 447 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 448                           struct net_device *dev)
 449 {
 450         struct net *net = container_of(fq->q.net, struct net, ipv6.frags);
 451         struct sk_buff *fp, *head = fq->q.fragments;
 452         int    payload_len;
 453         unsigned int nhoff;
 454
 455         fq_kill(fq);
 456
 457         /* Make the one we just received the head. */
 458         if (prev) {
 459                 head = prev->next;
 460                 fp = skb_clone(head, GFP_ATOMIC);
 461
 462                 if (!fp)
 463                         goto out_oom;
 464
 465                 fp->next = head->next;
 466                 prev->next = fp;
 467
 468                 skb_morph(head, fq->q.fragments);
 469                 head->next = fq->q.fragments->next;
 470
 471                 kfree_skb(fq->q.fragments);
 472                 fq->q.fragments = head;
 473         }
 474
 475         WARN_ON(head == NULL);
 476         WARN_ON(FRAG6_CB(head)->offset != 0);
 477
 478         /* Unfragmented part is taken from the first segment. */
 479         payload_len = ((head->data - skb_network_header(head)) -
 480                        sizeof(struct ipv6hdr) + fq->q.len -
 481                        sizeof(struct frag_hdr));
 482         if (payload_len > IPV6_MAXPLEN)
 483                 goto out_oversize;
 484
 485         /* Head of list must not be cloned. */
 486         if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
 487                 goto out_oom;
 488
 489         /* If the first fragment is fragmented itself, we split
 490          * it to two chunks: the first with data and paged part
 491          * and the second, holding only fragments. */
 492         if (skb_has_frags(head)) {
 493                 struct sk_buff *clone;
 494                 int i, plen = 0;
 495
 496                 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
 497                         goto out_oom;
 498                 clone->next = head->next;
 499                 head->next = clone;
 500                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
 501                 skb_frag_list_init(head);
 502                 for (i=0; i<skb_shinfo(head)->nr_frags; i++)
 503                         plen += skb_shinfo(head)->frags[i].size;
 504                 clone->len = clone->data_len = head->data_len - plen;
 505                 head->data_len -= clone->len;
 506                 head->len -= clone->len;
 507                 clone->csum = 0;
 508                 clone->ip_summed = head->ip_summed;
 509                 atomic_add(clone->truesize, &fq->q.net->mem);
 510         }
 511
 512         /* We have to remove fragment header from datagram and to relocate
 513          * header in order to calculate ICV correctly. */
 514         nhoff = fq->nhoffset;
 515         skb_network_header(head)[nhoff] = skb_transport_header(head)[0];
 516         memmove(head->head + sizeof(struct frag_hdr), head->head,
 517                 (head->data - head->head) - sizeof(struct frag_hdr));
 518         head->mac_header += sizeof(struct frag_hdr);
 519         head->network_header += sizeof(struct frag_hdr);
 520
 521         skb_shinfo(head)->frag_list = head->next;
 522         skb_reset_transport_header(head);
 523         skb_push(head, head->data - skb_network_header(head));
 524
 525         for (fp=head->next; fp; fp = fp->next) {
 526                 head->data_len += fp->len;
 527                 head->len += fp->len;
 528                 if (head->ip_summed != fp->ip_summed)
 529                         head->ip_summed = CHECKSUM_NONE;
 530                 else if (head->ip_summed == CHECKSUM_COMPLETE)
 531                         head->csum = csum_add(head->csum, fp->csum);
 532                 head->truesize += fp->truesize;
 533         }
 534         atomic_sub(head->truesize, &fq->q.net->mem);
 535
 536         head->next = NULL;
 537         head->dev = dev;
 538         head->tstamp = fq->q.stamp;
 539         ipv6_hdr(head)->payload_len = htons(payload_len);
 540         IP6CB(head)->nhoff = nhoff;
 541
 542         /* Yes, and fold redundant checksum back. 8) */
 543         if (head->ip_summed == CHECKSUM_COMPLETE)
 544                 head->csum = csum_partial(skb_network_header(head),
 545                                           skb_network_header_len(head),
 546                                           head->csum);
 547
 548         rcu_read_lock();
 549         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
 550         rcu_read_unlock();
 551         fq->q.fragments = NULL;
 552         return 1;
 553
 554 out_oversize:
 555         if (net_ratelimit())
 556                 printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len);
 557         goto out_fail;
 558 out_oom:
 559         if (net_ratelimit())
 560                 printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n");
 561 out_fail:
 562         rcu_read_lock();
 563         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
 564         rcu_read_unlock();
 565         return -1;
 566 }
 567
 568 static int ipv6_frag_rcv(struct sk_buff *skb)
 569 {
 570         struct frag_hdr *fhdr;
 571         struct frag_queue *fq;
 572         struct ipv6hdr *hdr = ipv6_hdr(skb);
 573         struct net *net = dev_net(skb_dst(skb)->dev);
 574
 575         IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS);
 576
 577         /* Jumbo payload inhibits frag. header */
 578         if (hdr->payload_len==0)
 579                 goto fail_hdr;
 580
 581         if (!pskb_may_pull(skb, (skb_transport_offset(skb) +
 582                                  sizeof(struct frag_hdr))))
 583                 goto fail_hdr;
 584
 585         hdr = ipv6_hdr(skb);
 586         fhdr = (struct frag_hdr *)skb_transport_header(skb);
 587
 588         if (!(fhdr->frag_off & htons(0xFFF9))) {
 589                 /* It is not a fragmented frame */
 590                 skb->transport_header += sizeof(struct frag_hdr);
 591                 IP6_INC_STATS_BH(net,
 592                                  ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS);
 593
 594                 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb);
 595                 return 1;
 596         }
 597
 598         if (atomic_read(&net->ipv6.frags.mem) > net->ipv6.frags.high_thresh)
 599                 ip6_evictor(net, ip6_dst_idev(skb_dst(skb)));
 600
 601         fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr);
 602         if (fq != NULL) {
 603                 int ret;
 604
 605                 spin_lock(&fq->q.lock);
 606
 607                 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
 608
 609                 spin_unlock(&fq->q.lock);
 610                 fq_put(fq);
 611                 return ret;
 612         }
 613
 614         IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS);
 615         kfree_skb(skb);
 616         return -1;
 617
 618 fail_hdr:
 619         IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS);
 620         icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb));
 621         return -1;
 622 }
 623
 624 static const struct inet6_protocol frag_protocol =
 625 {
 626         .handler        =       ipv6_frag_rcv,
 627         .flags          =       INET6_PROTO_NOPOLICY,
 628 };
 629
 630 #ifdef CONFIG_SYSCTL
 631 static struct ctl_table ip6_frags_ns_ctl_table[] = {
 632         {
 633                 .procname       = "ip6frag_high_thresh",
 634                 .data           = &init_net.ipv6.frags.high_thresh,
 635                 .maxlen         = sizeof(int),
 636                 .mode           = 0644,
 637                 .proc_handler   = proc_dointvec
 638         },
 639         {
 640                 .procname       = "ip6frag_low_thresh",
 641                 .data           = &init_net.ipv6.frags.low_thresh,
 642                 .maxlen         = sizeof(int),
 643                 .mode           = 0644,
 644                 .proc_handler   = proc_dointvec
 645         },
 646         {
 647                 .procname       = "ip6frag_time",
 648                 .data           = &init_net.ipv6.frags.timeout,
 649                 .maxlen         = sizeof(int),
 650                 .mode           = 0644,
 651                 .proc_handler   = proc_dointvec_jiffies,
 652         },
 653         { }
 654 };
 655
 656 static struct ctl_table ip6_frags_ctl_table[] = {
 657         {
 658                 .procname       = "ip6frag_secret_interval",
 659                 .data           = &ip6_frags.secret_interval,
 660                 .maxlen         = sizeof(int),
 661                 .mode           = 0644,
 662                 .proc_handler   = proc_dointvec_jiffies,
 663         },
 664         { }
 665 };
 666
 667 static int __net_init ip6_frags_ns_sysctl_register(struct net *net)
 668 {
 669         struct ctl_table *table;
 670         struct ctl_table_header *hdr;
 671
 672         table = ip6_frags_ns_ctl_table;
 673         if (!net_eq(net, &init_net)) {
 674                 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL);
 675                 if (table == NULL)
 676                         goto err_alloc;
 677
 678                 table[0].data = &net->ipv6.frags.high_thresh;
 679                 table[1].data = &net->ipv6.frags.low_thresh;
 680                 table[2].data = &net->ipv6.frags.timeout;
 681         }
 682
 683         hdr = register_net_sysctl_table(net, net_ipv6_ctl_path, table);
 684         if (hdr == NULL)
 685                 goto err_reg;
 686
 687         net->ipv6.sysctl.frags_hdr = hdr;
 688         return 0;
 689
 690 err_reg:
 691         if (!net_eq(net, &init_net))
 692                 kfree(table);
 693 err_alloc:
 694         return -ENOMEM;
 695 }
 696
 697 static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net)
 698 {
 699         struct ctl_table *table;
 700
 701         table = net->ipv6.sysctl.frags_hdr->ctl_table_arg;
 702         unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr);
 703         if (!net_eq(net, &init_net))
 704                 kfree(table);
 705 }
 706
 707 static struct ctl_table_header *ip6_ctl_header;
 708
 709 static int ip6_frags_sysctl_register(void)
 710 {
 711         ip6_ctl_header = register_net_sysctl_rotable(net_ipv6_ctl_path,
 712                         ip6_frags_ctl_table);
 713         return ip6_ctl_header == NULL ? -ENOMEM : 0;
 714 }
 715
 716 static void ip6_frags_sysctl_unregister(void)
 717 {
 718         unregister_net_sysctl_table(ip6_ctl_header);
 719 }
 720 #else
 721 static inline int ip6_frags_ns_sysctl_register(struct net *net)
 722 {
 723         return 0;
 724 }
 725
 726 static inline void ip6_frags_ns_sysctl_unregister(struct net *net)
 727 {
 728 }
 729
 730 static inline int ip6_frags_sysctl_register(void)
 731 {
 732         return 0;
 733 }
 734
 735 static inline void ip6_frags_sysctl_unregister(void)
 736 {
 737 }
 738 #endif
 739
 740 static int __net_init ipv6_frags_init_net(struct net *net)
 741 {
 742         net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH;
 743         net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH;
 744         net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT;
 745
 746         inet_frags_init_net(&net->ipv6.frags);
 747
 748         return ip6_frags_ns_sysctl_register(net);
 749 }
 750
 751 static void __net_exit ipv6_frags_exit_net(struct net *net)
 752 {
 753         ip6_frags_ns_sysctl_unregister(net);
 754         inet_frags_exit_net(&net->ipv6.frags, &ip6_frags);
 755 }
 756
 757 static struct pernet_operations ip6_frags_ops = {
 758         .init = ipv6_frags_init_net,
 759         .exit = ipv6_frags_exit_net,
 760 };
 761
 762 int __init ipv6_frag_init(void)
 763 {
 764         int ret;
 765
 766         ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT);
 767         if (ret)
 768                 goto out;
 769
 770         ret = ip6_frags_sysctl_register();
 771         if (ret)
 772                 goto err_sysctl;
 773
 774         ret = register_pernet_subsys(&ip6_frags_ops);
 775         if (ret)
 776                 goto err_pernet;
 777
 778         ip6_frags.hashfn = ip6_hashfn;
 779         ip6_frags.constructor = ip6_frag_init;
 780         ip6_frags.destructor = NULL;
 781         ip6_frags.skb_free = NULL;
 782         ip6_frags.qsize = sizeof(struct frag_queue);
 783         ip6_frags.match = ip6_frag_match;
 784         ip6_frags.frag_expire = ip6_frag_expire;
 785         ip6_frags.secret_interval = 10 * 60 * HZ;
 786         inet_frags_init(&ip6_frags);
 787 out:
 788         return ret;
 789
 790 err_pernet:
 791         ip6_frags_sysctl_unregister();
 792 err_sysctl:
 793         inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
 794         goto out;
 795 }
 796
 797 void ipv6_frag_exit(void)
 798 {
 799         inet_frags_fini(&ip6_frags);
 800         ip6_frags_sysctl_unregister();
 801         unregister_pernet_subsys(&ip6_frags_ops);
 802         inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
 803 }