Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
[linux-2.6.git] / 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
45 #include <net/sock.h>
46 #include <net/snmp.h>
47
48 #include <net/ipv6.h>
49 #include <net/ip6_route.h>
50 #include <net/protocol.h>
51 #include <net/transp_v6.h>
52 #include <net/rawv6.h>
53 #include <net/ndisc.h>
54 #include <net/addrconf.h>
55 #include <net/inet_frag.h>
56
57 struct ip6frag_skb_cb
58 {
59         struct inet6_skb_parm   h;
60         int                     offset;
61 };
62
63 #define FRAG6_CB(skb)   ((struct ip6frag_skb_cb*)((skb)->cb))
64
65
66 /*
67  *      Equivalent of ipv4 struct ipq
68  */
69
70 struct frag_queue
71 {
72         struct inet_frag_queue  q;
73
74         __be32                  id;             /* fragment id          */
75         struct in6_addr         saddr;
76         struct in6_addr         daddr;
77
78         int                     iif;
79         unsigned int            csum;
80         __u16                   nhoffset;
81 };
82
83 static struct inet_frags ip6_frags;
84
85 int ip6_frag_nqueues(struct net *net)
86 {
87         return net->ipv6.frags.nqueues;
88 }
89
90 int ip6_frag_mem(struct net *net)
91 {
92         return atomic_read(&net->ipv6.frags.mem);
93 }
94
95 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
96                           struct net_device *dev);
97
98 /*
99  * callers should be careful not to use the hash value outside the ipfrag_lock
100  * as doing so could race with ipfrag_hash_rnd being recalculated.
101  */
102 unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
103                              const struct in6_addr *daddr, u32 rnd)
104 {
105         u32 a, b, c;
106
107         a = (__force u32)saddr->s6_addr32[0];
108         b = (__force u32)saddr->s6_addr32[1];
109         c = (__force u32)saddr->s6_addr32[2];
110
111         a += JHASH_GOLDEN_RATIO;
112         b += JHASH_GOLDEN_RATIO;
113         c += rnd;
114         __jhash_mix(a, b, c);
115
116         a += (__force u32)saddr->s6_addr32[3];
117         b += (__force u32)daddr->s6_addr32[0];
118         c += (__force u32)daddr->s6_addr32[1];
119         __jhash_mix(a, b, c);
120
121         a += (__force u32)daddr->s6_addr32[2];
122         b += (__force u32)daddr->s6_addr32[3];
123         c += (__force u32)id;
124         __jhash_mix(a, b, c);
125
126         return c & (INETFRAGS_HASHSZ - 1);
127 }
128 EXPORT_SYMBOL_GPL(inet6_hash_frag);
129
130 static unsigned int ip6_hashfn(struct inet_frag_queue *q)
131 {
132         struct frag_queue *fq;
133
134         fq = container_of(q, struct frag_queue, q);
135         return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr, ip6_frags.rnd);
136 }
137
138 int ip6_frag_match(struct inet_frag_queue *q, void *a)
139 {
140         struct frag_queue *fq;
141         struct ip6_create_arg *arg = a;
142
143         fq = container_of(q, struct frag_queue, q);
144         return (fq->id == arg->id &&
145                         ipv6_addr_equal(&fq->saddr, arg->src) &&
146                         ipv6_addr_equal(&fq->daddr, arg->dst));
147 }
148 EXPORT_SYMBOL(ip6_frag_match);
149
150 /* Memory Tracking Functions. */
151 static inline void frag_kfree_skb(struct netns_frags *nf,
152                 struct sk_buff *skb, int *work)
153 {
154         if (work)
155                 *work -= skb->truesize;
156         atomic_sub(skb->truesize, &nf->mem);
157         kfree_skb(skb);
158 }
159
160 void ip6_frag_init(struct inet_frag_queue *q, void *a)
161 {
162         struct frag_queue *fq = container_of(q, struct frag_queue, q);
163         struct ip6_create_arg *arg = a;
164
165         fq->id = arg->id;
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         dev = dev_get_by_index(net, fq->iif);
212         if (!dev)
213                 goto out;
214
215         rcu_read_lock();
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         rcu_read_unlock();
219
220         /* Don't send error if the first segment did not arrive. */
221         if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments)
222                 goto out;
223
224         /*
225            But use as source device on which LAST ARRIVED
226            segment was received. And do not use fq->dev
227            pointer directly, device might already disappeared.
228          */
229         fq->q.fragments->dev = dev;
230         icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0, dev);
231 out:
232         if (dev)
233                 dev_put(dev);
234         spin_unlock(&fq->q.lock);
235         fq_put(fq);
236 }
237
238 static __inline__ struct frag_queue *
239 fq_find(struct net *net, __be32 id, struct in6_addr *src, struct in6_addr *dst,
240         struct inet6_dev *idev)
241 {
242         struct inet_frag_queue *q;
243         struct ip6_create_arg arg;
244         unsigned int hash;
245
246         arg.id = id;
247         arg.src = src;
248         arg.dst = dst;
249
250         read_lock(&ip6_frags.lock);
251         hash = inet6_hash_frag(id, src, dst, ip6_frags.rnd);
252
253         q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash);
254         if (q == NULL)
255                 goto oom;
256
257         return container_of(q, struct frag_queue, q);
258
259 oom:
260         IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_REASMFAILS);
261         return NULL;
262 }
263
264 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
265                            struct frag_hdr *fhdr, int nhoff)
266 {
267         struct sk_buff *prev, *next;
268         struct net_device *dev;
269         int offset, end;
270         struct net *net = dev_net(skb->dst->dev);
271
272         if (fq->q.last_in & INET_FRAG_COMPLETE)
273                 goto err;
274
275         offset = ntohs(fhdr->frag_off) & ~0x7;
276         end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
277                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
278
279         if ((unsigned int)end > IPV6_MAXPLEN) {
280                 IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst),
281                                  IPSTATS_MIB_INHDRERRORS);
282                 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
283                                   ((u8 *)&fhdr->frag_off -
284                                    skb_network_header(skb)));
285                 return -1;
286         }
287
288         if (skb->ip_summed == CHECKSUM_COMPLETE) {
289                 const unsigned char *nh = skb_network_header(skb);
290                 skb->csum = csum_sub(skb->csum,
291                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
292                                                   0));
293         }
294
295         /* Is this the final fragment? */
296         if (!(fhdr->frag_off & htons(IP6_MF))) {
297                 /* If we already have some bits beyond end
298                  * or have different end, the segment is corrupted.
299                  */
300                 if (end < fq->q.len ||
301                     ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len))
302                         goto err;
303                 fq->q.last_in |= INET_FRAG_LAST_IN;
304                 fq->q.len = end;
305         } else {
306                 /* Check if the fragment is rounded to 8 bytes.
307                  * Required by the RFC.
308                  */
309                 if (end & 0x7) {
310                         /* RFC2460 says always send parameter problem in
311                          * this case. -DaveM
312                          */
313                         IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst),
314                                          IPSTATS_MIB_INHDRERRORS);
315                         icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
316                                           offsetof(struct ipv6hdr, payload_len));
317                         return -1;
318                 }
319                 if (end > fq->q.len) {
320                         /* Some bits beyond end -> corruption. */
321                         if (fq->q.last_in & INET_FRAG_LAST_IN)
322                                 goto err;
323                         fq->q.len = end;
324                 }
325         }
326
327         if (end == offset)
328                 goto err;
329
330         /* Point into the IP datagram 'data' part. */
331         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
332                 goto err;
333
334         if (pskb_trim_rcsum(skb, end - offset))
335                 goto err;
336
337         /* Find out which fragments are in front and at the back of us
338          * in the chain of fragments so far.  We must know where to put
339          * this fragment, right?
340          */
341         prev = NULL;
342         for(next = fq->q.fragments; next != NULL; next = next->next) {
343                 if (FRAG6_CB(next)->offset >= offset)
344                         break;  /* bingo! */
345                 prev = next;
346         }
347
348         /* We found where to put this one.  Check for overlap with
349          * preceding fragment, and, if needed, align things so that
350          * any overlaps are eliminated.
351          */
352         if (prev) {
353                 int i = (FRAG6_CB(prev)->offset + prev->len) - offset;
354
355                 if (i > 0) {
356                         offset += i;
357                         if (end <= offset)
358                                 goto err;
359                         if (!pskb_pull(skb, i))
360                                 goto err;
361                         if (skb->ip_summed != CHECKSUM_UNNECESSARY)
362                                 skb->ip_summed = CHECKSUM_NONE;
363                 }
364         }
365
366         /* Look for overlap with succeeding segments.
367          * If we can merge fragments, do it.
368          */
369         while (next && FRAG6_CB(next)->offset < end) {
370                 int i = end - FRAG6_CB(next)->offset; /* overlap is 'i' bytes */
371
372                 if (i < next->len) {
373                         /* Eat head of the next overlapped fragment
374                          * and leave the loop. The next ones cannot overlap.
375                          */
376                         if (!pskb_pull(next, i))
377                                 goto err;
378                         FRAG6_CB(next)->offset += i;    /* next fragment */
379                         fq->q.meat -= i;
380                         if (next->ip_summed != CHECKSUM_UNNECESSARY)
381                                 next->ip_summed = CHECKSUM_NONE;
382                         break;
383                 } else {
384                         struct sk_buff *free_it = next;
385
386                         /* Old fragment is completely overridden with
387                          * new one drop it.
388                          */
389                         next = next->next;
390
391                         if (prev)
392                                 prev->next = next;
393                         else
394                                 fq->q.fragments = next;
395
396                         fq->q.meat -= free_it->len;
397                         frag_kfree_skb(fq->q.net, free_it, NULL);
398                 }
399         }
400
401         FRAG6_CB(skb)->offset = offset;
402
403         /* Insert this fragment in the chain of fragments. */
404         skb->next = next;
405         if (prev)
406                 prev->next = skb;
407         else
408                 fq->q.fragments = skb;
409
410         dev = skb->dev;
411         if (dev) {
412                 fq->iif = dev->ifindex;
413                 skb->dev = NULL;
414         }
415         fq->q.stamp = skb->tstamp;
416         fq->q.meat += skb->len;
417         atomic_add(skb->truesize, &fq->q.net->mem);
418
419         /* The first fragment.
420          * nhoffset is obtained from the first fragment, of course.
421          */
422         if (offset == 0) {
423                 fq->nhoffset = nhoff;
424                 fq->q.last_in |= INET_FRAG_FIRST_IN;
425         }
426
427         if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
428             fq->q.meat == fq->q.len)
429                 return ip6_frag_reasm(fq, prev, dev);
430
431         write_lock(&ip6_frags.lock);
432         list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list);
433         write_unlock(&ip6_frags.lock);
434         return -1;
435
436 err:
437         IP6_INC_STATS(net, ip6_dst_idev(skb->dst),
438                       IPSTATS_MIB_REASMFAILS);
439         kfree_skb(skb);
440         return -1;
441 }
442
443 /*
444  *      Check if this packet is complete.
445  *      Returns NULL on failure by any reason, and pointer
446  *      to current nexthdr field in reassembled frame.
447  *
448  *      It is called with locked fq, and caller must check that
449  *      queue is eligible for reassembly i.e. it is not COMPLETE,
450  *      the last and the first frames arrived and all the bits are here.
451  */
452 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
453                           struct net_device *dev)
454 {
455         struct sk_buff *fp, *head = fq->q.fragments;
456         int    payload_len;
457         unsigned int nhoff;
458
459         fq_kill(fq);
460
461         /* Make the one we just received the head. */
462         if (prev) {
463                 head = prev->next;
464                 fp = skb_clone(head, GFP_ATOMIC);
465
466                 if (!fp)
467                         goto out_oom;
468
469                 fp->next = head->next;
470                 prev->next = fp;
471
472                 skb_morph(head, fq->q.fragments);
473                 head->next = fq->q.fragments->next;
474
475                 kfree_skb(fq->q.fragments);
476                 fq->q.fragments = head;
477         }
478
479         WARN_ON(head == NULL);
480         WARN_ON(FRAG6_CB(head)->offset != 0);
481
482         /* Unfragmented part is taken from the first segment. */
483         payload_len = ((head->data - skb_network_header(head)) -
484                        sizeof(struct ipv6hdr) + fq->q.len -
485                        sizeof(struct frag_hdr));
486         if (payload_len > IPV6_MAXPLEN)
487                 goto out_oversize;
488
489         /* Head of list must not be cloned. */
490         if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
491                 goto out_oom;
492
493         /* If the first fragment is fragmented itself, we split
494          * it to two chunks: the first with data and paged part
495          * and the second, holding only fragments. */
496         if (skb_shinfo(head)->frag_list) {
497                 struct sk_buff *clone;
498                 int i, plen = 0;
499
500                 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
501                         goto out_oom;
502                 clone->next = head->next;
503                 head->next = clone;
504                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
505                 skb_shinfo(head)->frag_list = NULL;
506                 for (i=0; i<skb_shinfo(head)->nr_frags; i++)
507                         plen += skb_shinfo(head)->frags[i].size;
508                 clone->len = clone->data_len = head->data_len - plen;
509                 head->data_len -= clone->len;
510                 head->len -= clone->len;
511                 clone->csum = 0;
512                 clone->ip_summed = head->ip_summed;
513                 atomic_add(clone->truesize, &fq->q.net->mem);
514         }
515
516         /* We have to remove fragment header from datagram and to relocate
517          * header in order to calculate ICV correctly. */
518         nhoff = fq->nhoffset;
519         skb_network_header(head)[nhoff] = skb_transport_header(head)[0];
520         memmove(head->head + sizeof(struct frag_hdr), head->head,
521                 (head->data - head->head) - sizeof(struct frag_hdr));
522         head->mac_header += sizeof(struct frag_hdr);
523         head->network_header += sizeof(struct frag_hdr);
524
525         skb_shinfo(head)->frag_list = head->next;
526         skb_reset_transport_header(head);
527         skb_push(head, head->data - skb_network_header(head));
528         atomic_sub(head->truesize, &fq->q.net->mem);
529
530         for (fp=head->next; fp; fp = fp->next) {
531                 head->data_len += fp->len;
532                 head->len += fp->len;
533                 if (head->ip_summed != fp->ip_summed)
534                         head->ip_summed = CHECKSUM_NONE;
535                 else if (head->ip_summed == CHECKSUM_COMPLETE)
536                         head->csum = csum_add(head->csum, fp->csum);
537                 head->truesize += fp->truesize;
538                 atomic_sub(fp->truesize, &fq->q.net->mem);
539         }
540
541         head->next = NULL;
542         head->dev = dev;
543         head->tstamp = fq->q.stamp;
544         ipv6_hdr(head)->payload_len = htons(payload_len);
545         IP6CB(head)->nhoff = nhoff;
546
547         /* Yes, and fold redundant checksum back. 8) */
548         if (head->ip_summed == CHECKSUM_COMPLETE)
549                 head->csum = csum_partial(skb_network_header(head),
550                                           skb_network_header_len(head),
551                                           head->csum);
552
553         rcu_read_lock();
554         IP6_INC_STATS_BH(dev_net(dev),
555                          __in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
556         rcu_read_unlock();
557         fq->q.fragments = NULL;
558         return 1;
559
560 out_oversize:
561         if (net_ratelimit())
562                 printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len);
563         goto out_fail;
564 out_oom:
565         if (net_ratelimit())
566                 printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n");
567 out_fail:
568         rcu_read_lock();
569         IP6_INC_STATS_BH(dev_net(dev),
570                          __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
571         rcu_read_unlock();
572         return -1;
573 }
574
575 static int ipv6_frag_rcv(struct sk_buff *skb)
576 {
577         struct frag_hdr *fhdr;
578         struct frag_queue *fq;
579         struct ipv6hdr *hdr = ipv6_hdr(skb);
580         struct net *net = dev_net(skb->dst->dev);
581
582         IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMREQDS);
583
584         /* Jumbo payload inhibits frag. header */
585         if (hdr->payload_len==0)
586                 goto fail_hdr;
587
588         if (!pskb_may_pull(skb, (skb_transport_offset(skb) +
589                                  sizeof(struct frag_hdr))))
590                 goto fail_hdr;
591
592         hdr = ipv6_hdr(skb);
593         fhdr = (struct frag_hdr *)skb_transport_header(skb);
594
595         if (!(fhdr->frag_off & htons(0xFFF9))) {
596                 /* It is not a fragmented frame */
597                 skb->transport_header += sizeof(struct frag_hdr);
598                 IP6_INC_STATS_BH(net,
599                                  ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMOKS);
600
601                 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb);
602                 return 1;
603         }
604
605         if (atomic_read(&net->ipv6.frags.mem) > net->ipv6.frags.high_thresh)
606                 ip6_evictor(net, ip6_dst_idev(skb->dst));
607
608         if ((fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr,
609                           ip6_dst_idev(skb->dst))) != NULL) {
610                 int ret;
611
612                 spin_lock(&fq->q.lock);
613
614                 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
615
616                 spin_unlock(&fq->q.lock);
617                 fq_put(fq);
618                 return ret;
619         }
620
621         IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMFAILS);
622         kfree_skb(skb);
623         return -1;
624
625 fail_hdr:
626         IP6_INC_STATS(net, ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS);
627         icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb));
628         return -1;
629 }
630
631 static struct inet6_protocol frag_protocol =
632 {
633         .handler        =       ipv6_frag_rcv,
634         .flags          =       INET6_PROTO_NOPOLICY,
635 };
636
637 #ifdef CONFIG_SYSCTL
638 static struct ctl_table ip6_frags_ns_ctl_table[] = {
639         {
640                 .ctl_name       = NET_IPV6_IP6FRAG_HIGH_THRESH,
641                 .procname       = "ip6frag_high_thresh",
642                 .data           = &init_net.ipv6.frags.high_thresh,
643                 .maxlen         = sizeof(int),
644                 .mode           = 0644,
645                 .proc_handler   = proc_dointvec
646         },
647         {
648                 .ctl_name       = NET_IPV6_IP6FRAG_LOW_THRESH,
649                 .procname       = "ip6frag_low_thresh",
650                 .data           = &init_net.ipv6.frags.low_thresh,
651                 .maxlen         = sizeof(int),
652                 .mode           = 0644,
653                 .proc_handler   = proc_dointvec
654         },
655         {
656                 .ctl_name       = NET_IPV6_IP6FRAG_TIME,
657                 .procname       = "ip6frag_time",
658                 .data           = &init_net.ipv6.frags.timeout,
659                 .maxlen         = sizeof(int),
660                 .mode           = 0644,
661                 .proc_handler   = proc_dointvec_jiffies,
662                 .strategy       = sysctl_jiffies,
663         },
664         { }
665 };
666
667 static struct ctl_table ip6_frags_ctl_table[] = {
668         {
669                 .ctl_name       = NET_IPV6_IP6FRAG_SECRET_INTERVAL,
670                 .procname       = "ip6frag_secret_interval",
671                 .data           = &ip6_frags.secret_interval,
672                 .maxlen         = sizeof(int),
673                 .mode           = 0644,
674                 .proc_handler   = proc_dointvec_jiffies,
675                 .strategy       = sysctl_jiffies
676         },
677         { }
678 };
679
680 static int ip6_frags_ns_sysctl_register(struct net *net)
681 {
682         struct ctl_table *table;
683         struct ctl_table_header *hdr;
684
685         table = ip6_frags_ns_ctl_table;
686         if (net != &init_net) {
687                 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL);
688                 if (table == NULL)
689                         goto err_alloc;
690
691                 table[0].data = &net->ipv6.frags.high_thresh;
692                 table[1].data = &net->ipv6.frags.low_thresh;
693                 table[2].data = &net->ipv6.frags.timeout;
694         }
695
696         hdr = register_net_sysctl_table(net, net_ipv6_ctl_path, table);
697         if (hdr == NULL)
698                 goto err_reg;
699
700         net->ipv6.sysctl.frags_hdr = hdr;
701         return 0;
702
703 err_reg:
704         if (net != &init_net)
705                 kfree(table);
706 err_alloc:
707         return -ENOMEM;
708 }
709
710 static void ip6_frags_ns_sysctl_unregister(struct net *net)
711 {
712         struct ctl_table *table;
713
714         table = net->ipv6.sysctl.frags_hdr->ctl_table_arg;
715         unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr);
716         kfree(table);
717 }
718
719 static struct ctl_table_header *ip6_ctl_header;
720
721 static int ip6_frags_sysctl_register(void)
722 {
723         ip6_ctl_header = register_net_sysctl_rotable(net_ipv6_ctl_path,
724                         ip6_frags_ctl_table);
725         return ip6_ctl_header == NULL ? -ENOMEM : 0;
726 }
727
728 static void ip6_frags_sysctl_unregister(void)
729 {
730         unregister_net_sysctl_table(ip6_ctl_header);
731 }
732 #else
733 static inline int ip6_frags_ns_sysctl_register(struct net *net)
734 {
735         return 0;
736 }
737
738 static inline void ip6_frags_ns_sysctl_unregister(struct net *net)
739 {
740 }
741
742 static inline int ip6_frags_sysctl_register(void)
743 {
744         return 0;
745 }
746
747 static inline void ip6_frags_sysctl_unregister(void)
748 {
749 }
750 #endif
751
752 static int ipv6_frags_init_net(struct net *net)
753 {
754         net->ipv6.frags.high_thresh = 256 * 1024;
755         net->ipv6.frags.low_thresh = 192 * 1024;
756         net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT;
757
758         inet_frags_init_net(&net->ipv6.frags);
759
760         return ip6_frags_ns_sysctl_register(net);
761 }
762
763 static void ipv6_frags_exit_net(struct net *net)
764 {
765         ip6_frags_ns_sysctl_unregister(net);
766         inet_frags_exit_net(&net->ipv6.frags, &ip6_frags);
767 }
768
769 static struct pernet_operations ip6_frags_ops = {
770         .init = ipv6_frags_init_net,
771         .exit = ipv6_frags_exit_net,
772 };
773
774 int __init ipv6_frag_init(void)
775 {
776         int ret;
777
778         ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT);
779         if (ret)
780                 goto out;
781
782         ret = ip6_frags_sysctl_register();
783         if (ret)
784                 goto err_sysctl;
785
786         ret = register_pernet_subsys(&ip6_frags_ops);
787         if (ret)
788                 goto err_pernet;
789
790         ip6_frags.hashfn = ip6_hashfn;
791         ip6_frags.constructor = ip6_frag_init;
792         ip6_frags.destructor = NULL;
793         ip6_frags.skb_free = NULL;
794         ip6_frags.qsize = sizeof(struct frag_queue);
795         ip6_frags.match = ip6_frag_match;
796         ip6_frags.frag_expire = ip6_frag_expire;
797         ip6_frags.secret_interval = 10 * 60 * HZ;
798         inet_frags_init(&ip6_frags);
799 out:
800         return ret;
801
802 err_pernet:
803         ip6_frags_sysctl_unregister();
804 err_sysctl:
805         inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
806         goto out;
807 }
808
809 void ipv6_frag_exit(void)
810 {
811         inet_frags_fini(&ip6_frags);
812         ip6_frags_sysctl_unregister();
813         unregister_pernet_subsys(&ip6_frags_ops);
814         inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
815 }