Merge git://git.infradead.org/embedded-2.6
[linux-2.6] / 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 static unsigned int ip6qhashfn(__be32 id, struct in6_addr *saddr,
103                                struct in6_addr *daddr)
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 += ip6_frags.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
129 static unsigned int ip6_hashfn(struct inet_frag_queue *q)
130 {
131         struct frag_queue *fq;
132
133         fq = container_of(q, struct frag_queue, q);
134         return ip6qhashfn(fq->id, &fq->saddr, &fq->daddr);
135 }
136
137 int ip6_frag_match(struct inet_frag_queue *q, void *a)
138 {
139         struct frag_queue *fq;
140         struct ip6_create_arg *arg = a;
141
142         fq = container_of(q, struct frag_queue, q);
143         return (fq->id == arg->id &&
144                         ipv6_addr_equal(&fq->saddr, arg->src) &&
145                         ipv6_addr_equal(&fq->daddr, arg->dst));
146 }
147 EXPORT_SYMBOL(ip6_frag_match);
148
149 /* Memory Tracking Functions. */
150 static inline void frag_kfree_skb(struct netns_frags *nf,
151                 struct sk_buff *skb, int *work)
152 {
153         if (work)
154                 *work -= skb->truesize;
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         ipv6_addr_copy(&fq->saddr, arg->src);
166         ipv6_addr_copy(&fq->daddr, arg->dst);
167 }
168 EXPORT_SYMBOL(ip6_frag_init);
169
170 /* Destruction primitives. */
171
172 static __inline__ void fq_put(struct frag_queue *fq)
173 {
174         inet_frag_put(&fq->q, &ip6_frags);
175 }
176
177 /* Kill fq entry. It is not destroyed immediately,
178  * because caller (and someone more) holds reference count.
179  */
180 static __inline__ void fq_kill(struct frag_queue *fq)
181 {
182         inet_frag_kill(&fq->q, &ip6_frags);
183 }
184
185 static void ip6_evictor(struct net *net, struct inet6_dev *idev)
186 {
187         int evicted;
188
189         evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags);
190         if (evicted)
191                 IP6_ADD_STATS_BH(idev, IPSTATS_MIB_REASMFAILS, evicted);
192 }
193
194 static void ip6_frag_expire(unsigned long data)
195 {
196         struct frag_queue *fq;
197         struct net_device *dev = NULL;
198         struct net *net;
199
200         fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
201
202         spin_lock(&fq->q.lock);
203
204         if (fq->q.last_in & INET_FRAG_COMPLETE)
205                 goto out;
206
207         fq_kill(fq);
208
209         net = container_of(fq->q.net, struct net, ipv6.frags);
210         dev = dev_get_by_index(net, fq->iif);
211         if (!dev)
212                 goto out;
213
214         rcu_read_lock();
215         IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
216         IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
217         rcu_read_unlock();
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;
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, dev);
230 out:
231         if (dev)
232                 dev_put(dev);
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         struct inet6_dev *idev)
240 {
241         struct inet_frag_queue *q;
242         struct ip6_create_arg arg;
243         unsigned int hash;
244
245         arg.id = id;
246         arg.src = src;
247         arg.dst = dst;
248
249         read_lock(&ip6_frags.lock);
250         hash = ip6qhashfn(id, src, dst);
251
252         q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash);
253         if (q == NULL)
254                 goto oom;
255
256         return container_of(q, struct frag_queue, q);
257
258 oom:
259         IP6_INC_STATS_BH(idev, IPSTATS_MIB_REASMFAILS);
260         return NULL;
261 }
262
263 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
264                            struct frag_hdr *fhdr, int nhoff)
265 {
266         struct sk_buff *prev, *next;
267         struct net_device *dev;
268         int offset, end;
269
270         if (fq->q.last_in & INET_FRAG_COMPLETE)
271                 goto err;
272
273         offset = ntohs(fhdr->frag_off) & ~0x7;
274         end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
275                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
276
277         if ((unsigned int)end > IPV6_MAXPLEN) {
278                 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
279                                  IPSTATS_MIB_INHDRERRORS);
280                 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
281                                   ((u8 *)&fhdr->frag_off -
282                                    skb_network_header(skb)));
283                 return -1;
284         }
285
286         if (skb->ip_summed == CHECKSUM_COMPLETE) {
287                 const unsigned char *nh = skb_network_header(skb);
288                 skb->csum = csum_sub(skb->csum,
289                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
290                                                   0));
291         }
292
293         /* Is this the final fragment? */
294         if (!(fhdr->frag_off & htons(IP6_MF))) {
295                 /* If we already have some bits beyond end
296                  * or have different end, the segment is corrupted.
297                  */
298                 if (end < fq->q.len ||
299                     ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len))
300                         goto err;
301                 fq->q.last_in |= INET_FRAG_LAST_IN;
302                 fq->q.len = end;
303         } else {
304                 /* Check if the fragment is rounded to 8 bytes.
305                  * Required by the RFC.
306                  */
307                 if (end & 0x7) {
308                         /* RFC2460 says always send parameter problem in
309                          * this case. -DaveM
310                          */
311                         IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
312                                          IPSTATS_MIB_INHDRERRORS);
313                         icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
314                                           offsetof(struct ipv6hdr, payload_len));
315                         return -1;
316                 }
317                 if (end > fq->q.len) {
318                         /* Some bits beyond end -> corruption. */
319                         if (fq->q.last_in & INET_FRAG_LAST_IN)
320                                 goto err;
321                         fq->q.len = end;
322                 }
323         }
324
325         if (end == offset)
326                 goto err;
327
328         /* Point into the IP datagram 'data' part. */
329         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
330                 goto err;
331
332         if (pskb_trim_rcsum(skb, end - offset))
333                 goto err;
334
335         /* Find out which fragments are in front and at the back of us
336          * in the chain of fragments so far.  We must know where to put
337          * this fragment, right?
338          */
339         prev = NULL;
340         for(next = fq->q.fragments; next != NULL; next = next->next) {
341                 if (FRAG6_CB(next)->offset >= offset)
342                         break;  /* bingo! */
343                 prev = next;
344         }
345
346         /* We found where to put this one.  Check for overlap with
347          * preceding fragment, and, if needed, align things so that
348          * any overlaps are eliminated.
349          */
350         if (prev) {
351                 int i = (FRAG6_CB(prev)->offset + prev->len) - offset;
352
353                 if (i > 0) {
354                         offset += i;
355                         if (end <= offset)
356                                 goto err;
357                         if (!pskb_pull(skb, i))
358                                 goto err;
359                         if (skb->ip_summed != CHECKSUM_UNNECESSARY)
360                                 skb->ip_summed = CHECKSUM_NONE;
361                 }
362         }
363
364         /* Look for overlap with succeeding segments.
365          * If we can merge fragments, do it.
366          */
367         while (next && FRAG6_CB(next)->offset < end) {
368                 int i = end - FRAG6_CB(next)->offset; /* overlap is 'i' bytes */
369
370                 if (i < next->len) {
371                         /* Eat head of the next overlapped fragment
372                          * and leave the loop. The next ones cannot overlap.
373                          */
374                         if (!pskb_pull(next, i))
375                                 goto err;
376                         FRAG6_CB(next)->offset += i;    /* next fragment */
377                         fq->q.meat -= i;
378                         if (next->ip_summed != CHECKSUM_UNNECESSARY)
379                                 next->ip_summed = CHECKSUM_NONE;
380                         break;
381                 } else {
382                         struct sk_buff *free_it = next;
383
384                         /* Old fragment is completely overridden with
385                          * new one drop it.
386                          */
387                         next = next->next;
388
389                         if (prev)
390                                 prev->next = next;
391                         else
392                                 fq->q.fragments = next;
393
394                         fq->q.meat -= free_it->len;
395                         frag_kfree_skb(fq->q.net, free_it, NULL);
396                 }
397         }
398
399         FRAG6_CB(skb)->offset = offset;
400
401         /* Insert this fragment in the chain of fragments. */
402         skb->next = next;
403         if (prev)
404                 prev->next = skb;
405         else
406                 fq->q.fragments = skb;
407
408         dev = skb->dev;
409         if (dev) {
410                 fq->iif = dev->ifindex;
411                 skb->dev = NULL;
412         }
413         fq->q.stamp = skb->tstamp;
414         fq->q.meat += skb->len;
415         atomic_add(skb->truesize, &fq->q.net->mem);
416
417         /* The first fragment.
418          * nhoffset is obtained from the first fragment, of course.
419          */
420         if (offset == 0) {
421                 fq->nhoffset = nhoff;
422                 fq->q.last_in |= INET_FRAG_FIRST_IN;
423         }
424
425         if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
426             fq->q.meat == fq->q.len)
427                 return ip6_frag_reasm(fq, prev, dev);
428
429         write_lock(&ip6_frags.lock);
430         list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list);
431         write_unlock(&ip6_frags.lock);
432         return -1;
433
434 err:
435         IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMFAILS);
436         kfree_skb(skb);
437         return -1;
438 }
439
440 /*
441  *      Check if this packet is complete.
442  *      Returns NULL on failure by any reason, and pointer
443  *      to current nexthdr field in reassembled frame.
444  *
445  *      It is called with locked fq, and caller must check that
446  *      queue is eligible for reassembly i.e. it is not COMPLETE,
447  *      the last and the first frames arrived and all the bits are here.
448  */
449 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
450                           struct net_device *dev)
451 {
452         struct sk_buff *fp, *head = fq->q.fragments;
453         int    payload_len;
454         unsigned int nhoff;
455
456         fq_kill(fq);
457
458         /* Make the one we just received the head. */
459         if (prev) {
460                 head = prev->next;
461                 fp = skb_clone(head, GFP_ATOMIC);
462
463                 if (!fp)
464                         goto out_oom;
465
466                 fp->next = head->next;
467                 prev->next = fp;
468
469                 skb_morph(head, fq->q.fragments);
470                 head->next = fq->q.fragments->next;
471
472                 kfree_skb(fq->q.fragments);
473                 fq->q.fragments = head;
474         }
475
476         BUG_TRAP(head != NULL);
477         BUG_TRAP(FRAG6_CB(head)->offset == 0);
478
479         /* Unfragmented part is taken from the first segment. */
480         payload_len = ((head->data - skb_network_header(head)) -
481                        sizeof(struct ipv6hdr) + fq->q.len -
482                        sizeof(struct frag_hdr));
483         if (payload_len > IPV6_MAXPLEN)
484                 goto out_oversize;
485
486         /* Head of list must not be cloned. */
487         if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
488                 goto out_oom;
489
490         /* If the first fragment is fragmented itself, we split
491          * it to two chunks: the first with data and paged part
492          * and the second, holding only fragments. */
493         if (skb_shinfo(head)->frag_list) {
494                 struct sk_buff *clone;
495                 int i, plen = 0;
496
497                 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
498                         goto out_oom;
499                 clone->next = head->next;
500                 head->next = clone;
501                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
502                 skb_shinfo(head)->frag_list = NULL;
503                 for (i=0; i<skb_shinfo(head)->nr_frags; i++)
504                         plen += skb_shinfo(head)->frags[i].size;
505                 clone->len = clone->data_len = head->data_len - plen;
506                 head->data_len -= clone->len;
507                 head->len -= clone->len;
508                 clone->csum = 0;
509                 clone->ip_summed = head->ip_summed;
510                 atomic_add(clone->truesize, &fq->q.net->mem);
511         }
512
513         /* We have to remove fragment header from datagram and to relocate
514          * header in order to calculate ICV correctly. */
515         nhoff = fq->nhoffset;
516         skb_network_header(head)[nhoff] = skb_transport_header(head)[0];
517         memmove(head->head + sizeof(struct frag_hdr), head->head,
518                 (head->data - head->head) - sizeof(struct frag_hdr));
519         head->mac_header += sizeof(struct frag_hdr);
520         head->network_header += sizeof(struct frag_hdr);
521
522         skb_shinfo(head)->frag_list = head->next;
523         skb_reset_transport_header(head);
524         skb_push(head, head->data - skb_network_header(head));
525         atomic_sub(head->truesize, &fq->q.net->mem);
526
527         for (fp=head->next; fp; fp = fp->next) {
528                 head->data_len += fp->len;
529                 head->len += fp->len;
530                 if (head->ip_summed != fp->ip_summed)
531                         head->ip_summed = CHECKSUM_NONE;
532                 else if (head->ip_summed == CHECKSUM_COMPLETE)
533                         head->csum = csum_add(head->csum, fp->csum);
534                 head->truesize += fp->truesize;
535                 atomic_sub(fp->truesize, &fq->q.net->mem);
536         }
537
538         head->next = NULL;
539         head->dev = dev;
540         head->tstamp = fq->q.stamp;
541         ipv6_hdr(head)->payload_len = htons(payload_len);
542         IP6CB(head)->nhoff = nhoff;
543
544         /* Yes, and fold redundant checksum back. 8) */
545         if (head->ip_summed == CHECKSUM_COMPLETE)
546                 head->csum = csum_partial(skb_network_header(head),
547                                           skb_network_header_len(head),
548                                           head->csum);
549
550         rcu_read_lock();
551         IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
552         rcu_read_unlock();
553         fq->q.fragments = NULL;
554         return 1;
555
556 out_oversize:
557         if (net_ratelimit())
558                 printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len);
559         goto out_fail;
560 out_oom:
561         if (net_ratelimit())
562                 printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n");
563 out_fail:
564         rcu_read_lock();
565         IP6_INC_STATS_BH(__in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
566         rcu_read_unlock();
567         return -1;
568 }
569
570 static int ipv6_frag_rcv(struct sk_buff *skb)
571 {
572         struct frag_hdr *fhdr;
573         struct frag_queue *fq;
574         struct ipv6hdr *hdr = ipv6_hdr(skb);
575         struct net *net;
576
577         IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMREQDS);
578
579         /* Jumbo payload inhibits frag. header */
580         if (hdr->payload_len==0) {
581                 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS);
582                 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
583                                   skb_network_header_len(skb));
584                 return -1;
585         }
586         if (!pskb_may_pull(skb, (skb_transport_offset(skb) +
587                                  sizeof(struct frag_hdr)))) {
588                 IP6_INC_STATS(ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS);
589                 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
590                                   skb_network_header_len(skb));
591                 return -1;
592         }
593
594         hdr = ipv6_hdr(skb);
595         fhdr = (struct frag_hdr *)skb_transport_header(skb);
596
597         if (!(fhdr->frag_off & htons(0xFFF9))) {
598                 /* It is not a fragmented frame */
599                 skb->transport_header += sizeof(struct frag_hdr);
600                 IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMOKS);
601
602                 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb);
603                 return 1;
604         }
605
606         net = dev_net(skb->dev);
607         if (atomic_read(&net->ipv6.frags.mem) > net->ipv6.frags.high_thresh)
608                 ip6_evictor(net, ip6_dst_idev(skb->dst));
609
610         if ((fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr,
611                           ip6_dst_idev(skb->dst))) != NULL) {
612                 int ret;
613
614                 spin_lock(&fq->q.lock);
615
616                 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
617
618                 spin_unlock(&fq->q.lock);
619                 fq_put(fq);
620                 return ret;
621         }
622
623         IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMFAILS);
624         kfree_skb(skb);
625         return -1;
626 }
627
628 static struct inet6_protocol frag_protocol =
629 {
630         .handler        =       ipv6_frag_rcv,
631         .flags          =       INET6_PROTO_NOPOLICY,
632 };
633
634 #ifdef CONFIG_SYSCTL
635 static struct ctl_table ip6_frags_ns_ctl_table[] = {
636         {
637                 .ctl_name       = NET_IPV6_IP6FRAG_HIGH_THRESH,
638                 .procname       = "ip6frag_high_thresh",
639                 .data           = &init_net.ipv6.frags.high_thresh,
640                 .maxlen         = sizeof(int),
641                 .mode           = 0644,
642                 .proc_handler   = &proc_dointvec
643         },
644         {
645                 .ctl_name       = NET_IPV6_IP6FRAG_LOW_THRESH,
646                 .procname       = "ip6frag_low_thresh",
647                 .data           = &init_net.ipv6.frags.low_thresh,
648                 .maxlen         = sizeof(int),
649                 .mode           = 0644,
650                 .proc_handler   = &proc_dointvec
651         },
652         {
653                 .ctl_name       = NET_IPV6_IP6FRAG_TIME,
654                 .procname       = "ip6frag_time",
655                 .data           = &init_net.ipv6.frags.timeout,
656                 .maxlen         = sizeof(int),
657                 .mode           = 0644,
658                 .proc_handler   = &proc_dointvec_jiffies,
659                 .strategy       = &sysctl_jiffies,
660         },
661         { }
662 };
663
664 static struct ctl_table ip6_frags_ctl_table[] = {
665         {
666                 .ctl_name       = NET_IPV6_IP6FRAG_SECRET_INTERVAL,
667                 .procname       = "ip6frag_secret_interval",
668                 .data           = &ip6_frags.secret_interval,
669                 .maxlen         = sizeof(int),
670                 .mode           = 0644,
671                 .proc_handler   = &proc_dointvec_jiffies,
672                 .strategy       = &sysctl_jiffies
673         },
674         { }
675 };
676
677 static int ip6_frags_ns_sysctl_register(struct net *net)
678 {
679         struct ctl_table *table;
680         struct ctl_table_header *hdr;
681
682         table = ip6_frags_ns_ctl_table;
683         if (net != &init_net) {
684                 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL);
685                 if (table == NULL)
686                         goto err_alloc;
687
688                 table[0].data = &net->ipv6.frags.high_thresh;
689                 table[1].data = &net->ipv6.frags.low_thresh;
690                 table[2].data = &net->ipv6.frags.timeout;
691         }
692
693         hdr = register_net_sysctl_table(net, net_ipv6_ctl_path, table);
694         if (hdr == NULL)
695                 goto err_reg;
696
697         net->ipv6.sysctl.frags_hdr = hdr;
698         return 0;
699
700 err_reg:
701         if (net != &init_net)
702                 kfree(table);
703 err_alloc:
704         return -ENOMEM;
705 }
706
707 static void ip6_frags_ns_sysctl_unregister(struct net *net)
708 {
709         struct ctl_table *table;
710
711         table = net->ipv6.sysctl.frags_hdr->ctl_table_arg;
712         unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr);
713         kfree(table);
714 }
715
716 static struct ctl_table_header *ip6_ctl_header;
717
718 static int ip6_frags_sysctl_register(void)
719 {
720         ip6_ctl_header = register_net_sysctl_rotable(net_ipv6_ctl_path,
721                         ip6_frags_ctl_table);
722         return ip6_ctl_header == NULL ? -ENOMEM : 0;
723 }
724
725 static void ip6_frags_sysctl_unregister(void)
726 {
727         unregister_net_sysctl_table(ip6_ctl_header);
728 }
729 #else
730 static inline int ip6_frags_ns_sysctl_register(struct net *net)
731 {
732         return 0;
733 }
734
735 static inline void ip6_frags_ns_sysctl_unregister(struct net *net)
736 {
737 }
738
739 static inline int ip6_frags_sysctl_register(void)
740 {
741         return 0;
742 }
743
744 static inline void ip6_frags_sysctl_unregister(void)
745 {
746 }
747 #endif
748
749 static int ipv6_frags_init_net(struct net *net)
750 {
751         net->ipv6.frags.high_thresh = 256 * 1024;
752         net->ipv6.frags.low_thresh = 192 * 1024;
753         net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT;
754
755         inet_frags_init_net(&net->ipv6.frags);
756
757         return ip6_frags_ns_sysctl_register(net);
758 }
759
760 static void ipv6_frags_exit_net(struct net *net)
761 {
762         ip6_frags_ns_sysctl_unregister(net);
763         inet_frags_exit_net(&net->ipv6.frags, &ip6_frags);
764 }
765
766 static struct pernet_operations ip6_frags_ops = {
767         .init = ipv6_frags_init_net,
768         .exit = ipv6_frags_exit_net,
769 };
770
771 int __init ipv6_frag_init(void)
772 {
773         int ret;
774
775         ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT);
776         if (ret)
777                 goto out;
778
779         ret = ip6_frags_sysctl_register();
780         if (ret)
781                 goto err_sysctl;
782
783         ret = register_pernet_subsys(&ip6_frags_ops);
784         if (ret)
785                 goto err_pernet;
786
787         ip6_frags.hashfn = ip6_hashfn;
788         ip6_frags.constructor = ip6_frag_init;
789         ip6_frags.destructor = NULL;
790         ip6_frags.skb_free = NULL;
791         ip6_frags.qsize = sizeof(struct frag_queue);
792         ip6_frags.match = ip6_frag_match;
793         ip6_frags.frag_expire = ip6_frag_expire;
794         ip6_frags.secret_interval = 10 * 60 * HZ;
795         inet_frags_init(&ip6_frags);
796 out:
797         return ret;
798
799 err_pernet:
800         ip6_frags_sysctl_unregister();
801 err_sysctl:
802         inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
803         goto out;
804 }
805
806 void ipv6_frag_exit(void)
807 {
808         inet_frags_fini(&ip6_frags);
809         ip6_frags_sysctl_unregister();
810         unregister_pernet_subsys(&ip6_frags_ops);
811         inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
812 }