dfb164e9051aef20af12cba8072dae4dfdb058e5
[pandora-kernel.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 #include <linux/slab.h>
45 #include <linux/export.h>
46
47 #include <net/sock.h>
48 #include <net/snmp.h>
49
50 #include <net/ipv6.h>
51 #include <net/ip6_route.h>
52 #include <net/protocol.h>
53 #include <net/transp_v6.h>
54 #include <net/rawv6.h>
55 #include <net/ndisc.h>
56 #include <net/addrconf.h>
57 #include <net/inet_frag.h>
58
59 struct ip6frag_skb_cb
60 {
61         struct inet6_skb_parm   h;
62         int                     offset;
63 };
64
65 #define FRAG6_CB(skb)   ((struct ip6frag_skb_cb*)((skb)->cb))
66
67
68 /*
69  *      Equivalent of ipv4 struct ipq
70  */
71
72 struct frag_queue
73 {
74         struct inet_frag_queue  q;
75
76         __be32                  id;             /* fragment id          */
77         u32                     user;
78         struct in6_addr         saddr;
79         struct in6_addr         daddr;
80
81         int                     iif;
82         unsigned int            csum;
83         __u16                   nhoffset;
84 };
85
86 static struct inet_frags ip6_frags;
87
88 int ip6_frag_nqueues(struct net *net)
89 {
90         return net->ipv6.frags.nqueues;
91 }
92
93 int ip6_frag_mem(struct net *net)
94 {
95         return atomic_read(&net->ipv6.frags.mem);
96 }
97
98 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
99                           struct net_device *dev);
100
101 /*
102  * callers should be careful not to use the hash value outside the ipfrag_lock
103  * as doing so could race with ipfrag_hash_rnd being recalculated.
104  */
105 unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
106                              const struct in6_addr *daddr, u32 rnd)
107 {
108         u32 c;
109
110         c = jhash_3words((__force u32)saddr->s6_addr32[0],
111                          (__force u32)saddr->s6_addr32[1],
112                          (__force u32)saddr->s6_addr32[2],
113                          rnd);
114
115         c = jhash_3words((__force u32)saddr->s6_addr32[3],
116                          (__force u32)daddr->s6_addr32[0],
117                          (__force u32)daddr->s6_addr32[1],
118                          c);
119
120         c =  jhash_3words((__force u32)daddr->s6_addr32[2],
121                           (__force u32)daddr->s6_addr32[3],
122                           (__force u32)id,
123                           c);
124
125         return c & (INETFRAGS_HASHSZ - 1);
126 }
127 EXPORT_SYMBOL_GPL(inet6_hash_frag);
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 inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr, ip6_frags.rnd);
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 && fq->user == arg->user &&
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 void ip6_frag_init(struct inet_frag_queue *q, void *a)
150 {
151         struct frag_queue *fq = container_of(q, struct frag_queue, q);
152         struct ip6_create_arg *arg = a;
153
154         fq->id = arg->id;
155         fq->user = arg->user;
156         ipv6_addr_copy(&fq->saddr, arg->src);
157         ipv6_addr_copy(&fq->daddr, arg->dst);
158 }
159 EXPORT_SYMBOL(ip6_frag_init);
160
161 /* Destruction primitives. */
162
163 static __inline__ void fq_put(struct frag_queue *fq)
164 {
165         inet_frag_put(&fq->q, &ip6_frags);
166 }
167
168 /* Kill fq entry. It is not destroyed immediately,
169  * because caller (and someone more) holds reference count.
170  */
171 static __inline__ void fq_kill(struct frag_queue *fq)
172 {
173         inet_frag_kill(&fq->q, &ip6_frags);
174 }
175
176 static void ip6_evictor(struct net *net, struct inet6_dev *idev)
177 {
178         int evicted;
179
180         evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags);
181         if (evicted)
182                 IP6_ADD_STATS_BH(net, idev, IPSTATS_MIB_REASMFAILS, evicted);
183 }
184
185 static void ip6_frag_expire(unsigned long data)
186 {
187         struct frag_queue *fq;
188         struct net_device *dev = NULL;
189         struct net *net;
190
191         fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
192
193         spin_lock(&fq->q.lock);
194
195         if (fq->q.last_in & INET_FRAG_COMPLETE)
196                 goto out;
197
198         fq_kill(fq);
199
200         net = container_of(fq->q.net, struct net, ipv6.frags);
201         rcu_read_lock();
202         dev = dev_get_by_index_rcu(net, fq->iif);
203         if (!dev)
204                 goto out_rcu_unlock;
205
206         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
207         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
208
209         /* Don't send error if the first segment did not arrive. */
210         if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments)
211                 goto out_rcu_unlock;
212
213         /*
214            But use as source device on which LAST ARRIVED
215            segment was received. And do not use fq->dev
216            pointer directly, device might already disappeared.
217          */
218         fq->q.fragments->dev = dev;
219         icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
220 out_rcu_unlock:
221         rcu_read_unlock();
222 out:
223         spin_unlock(&fq->q.lock);
224         fq_put(fq);
225 }
226
227 static __inline__ struct frag_queue *
228 fq_find(struct net *net, __be32 id, const struct in6_addr *src, const struct in6_addr *dst)
229 {
230         struct inet_frag_queue *q;
231         struct ip6_create_arg arg;
232         unsigned int hash;
233
234         arg.id = id;
235         arg.user = IP6_DEFRAG_LOCAL_DELIVER;
236         arg.src = src;
237         arg.dst = dst;
238
239         read_lock(&ip6_frags.lock);
240         hash = inet6_hash_frag(id, src, dst, ip6_frags.rnd);
241
242         q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash);
243         if (q == NULL)
244                 return NULL;
245
246         return container_of(q, struct frag_queue, q);
247 }
248
249 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
250                            struct frag_hdr *fhdr, int nhoff)
251 {
252         struct sk_buff *prev, *next;
253         struct net_device *dev;
254         int offset, end;
255         struct net *net = dev_net(skb_dst(skb)->dev);
256
257         if (fq->q.last_in & INET_FRAG_COMPLETE)
258                 goto err;
259
260         offset = ntohs(fhdr->frag_off) & ~0x7;
261         end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
262                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
263
264         if ((unsigned int)end > IPV6_MAXPLEN) {
265                 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
266                                  IPSTATS_MIB_INHDRERRORS);
267                 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
268                                   ((u8 *)&fhdr->frag_off -
269                                    skb_network_header(skb)));
270                 return -1;
271         }
272
273         if (skb->ip_summed == CHECKSUM_COMPLETE) {
274                 const unsigned char *nh = skb_network_header(skb);
275                 skb->csum = csum_sub(skb->csum,
276                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
277                                                   0));
278         }
279
280         /* Is this the final fragment? */
281         if (!(fhdr->frag_off & htons(IP6_MF))) {
282                 /* If we already have some bits beyond end
283                  * or have different end, the segment is corrupted.
284                  */
285                 if (end < fq->q.len ||
286                     ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len))
287                         goto err;
288                 fq->q.last_in |= INET_FRAG_LAST_IN;
289                 fq->q.len = end;
290         } else {
291                 /* Check if the fragment is rounded to 8 bytes.
292                  * Required by the RFC.
293                  */
294                 if (end & 0x7) {
295                         /* RFC2460 says always send parameter problem in
296                          * this case. -DaveM
297                          */
298                         IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
299                                          IPSTATS_MIB_INHDRERRORS);
300                         icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
301                                           offsetof(struct ipv6hdr, payload_len));
302                         return -1;
303                 }
304                 if (end > fq->q.len) {
305                         /* Some bits beyond end -> corruption. */
306                         if (fq->q.last_in & INET_FRAG_LAST_IN)
307                                 goto err;
308                         fq->q.len = end;
309                 }
310         }
311
312         if (end == offset)
313                 goto err;
314
315         /* Point into the IP datagram 'data' part. */
316         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
317                 goto err;
318
319         if (pskb_trim_rcsum(skb, end - offset))
320                 goto err;
321
322         /* Find out which fragments are in front and at the back of us
323          * in the chain of fragments so far.  We must know where to put
324          * this fragment, right?
325          */
326         prev = fq->q.fragments_tail;
327         if (!prev || FRAG6_CB(prev)->offset < offset) {
328                 next = NULL;
329                 goto found;
330         }
331         prev = NULL;
332         for(next = fq->q.fragments; next != NULL; next = next->next) {
333                 if (FRAG6_CB(next)->offset >= offset)
334                         break;  /* bingo! */
335                 prev = next;
336         }
337
338 found:
339         /* RFC5722, Section 4:
340          *                                  When reassembling an IPv6 datagram, if
341          *   one or more its constituent fragments is determined to be an
342          *   overlapping fragment, the entire datagram (and any constituent
343          *   fragments, including those not yet received) MUST be silently
344          *   discarded.
345          */
346
347         /* Check for overlap with preceding fragment. */
348         if (prev &&
349             (FRAG6_CB(prev)->offset + prev->len) > offset)
350                 goto discard_fq;
351
352         /* Look for overlap with succeeding segment. */
353         if (next && FRAG6_CB(next)->offset < end)
354                 goto discard_fq;
355
356         FRAG6_CB(skb)->offset = offset;
357
358         /* Insert this fragment in the chain of fragments. */
359         skb->next = next;
360         if (!next)
361                 fq->q.fragments_tail = skb;
362         if (prev)
363                 prev->next = skb;
364         else
365                 fq->q.fragments = skb;
366
367         dev = skb->dev;
368         if (dev) {
369                 fq->iif = dev->ifindex;
370                 skb->dev = NULL;
371         }
372         fq->q.stamp = skb->tstamp;
373         fq->q.meat += skb->len;
374         atomic_add(skb->truesize, &fq->q.net->mem);
375
376         /* The first fragment.
377          * nhoffset is obtained from the first fragment, of course.
378          */
379         if (offset == 0) {
380                 fq->nhoffset = nhoff;
381                 fq->q.last_in |= INET_FRAG_FIRST_IN;
382         }
383
384         if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
385             fq->q.meat == fq->q.len)
386                 return ip6_frag_reasm(fq, prev, dev);
387
388         write_lock(&ip6_frags.lock);
389         list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list);
390         write_unlock(&ip6_frags.lock);
391         return -1;
392
393 discard_fq:
394         fq_kill(fq);
395 err:
396         IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
397                       IPSTATS_MIB_REASMFAILS);
398         kfree_skb(skb);
399         return -1;
400 }
401
402 /*
403  *      Check if this packet is complete.
404  *      Returns NULL on failure by any reason, and pointer
405  *      to current nexthdr field in reassembled frame.
406  *
407  *      It is called with locked fq, and caller must check that
408  *      queue is eligible for reassembly i.e. it is not COMPLETE,
409  *      the last and the first frames arrived and all the bits are here.
410  */
411 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
412                           struct net_device *dev)
413 {
414         struct net *net = container_of(fq->q.net, struct net, ipv6.frags);
415         struct sk_buff *fp, *head = fq->q.fragments;
416         int    payload_len;
417         unsigned int nhoff;
418
419         fq_kill(fq);
420
421         /* Make the one we just received the head. */
422         if (prev) {
423                 head = prev->next;
424                 fp = skb_clone(head, GFP_ATOMIC);
425
426                 if (!fp)
427                         goto out_oom;
428
429                 fp->next = head->next;
430                 if (!fp->next)
431                         fq->q.fragments_tail = fp;
432                 prev->next = fp;
433
434                 skb_morph(head, fq->q.fragments);
435                 head->next = fq->q.fragments->next;
436
437                 kfree_skb(fq->q.fragments);
438                 fq->q.fragments = head;
439         }
440
441         WARN_ON(head == NULL);
442         WARN_ON(FRAG6_CB(head)->offset != 0);
443
444         /* Unfragmented part is taken from the first segment. */
445         payload_len = ((head->data - skb_network_header(head)) -
446                        sizeof(struct ipv6hdr) + fq->q.len -
447                        sizeof(struct frag_hdr));
448         if (payload_len > IPV6_MAXPLEN)
449                 goto out_oversize;
450
451         /* Head of list must not be cloned. */
452         if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
453                 goto out_oom;
454
455         /* If the first fragment is fragmented itself, we split
456          * it to two chunks: the first with data and paged part
457          * and the second, holding only fragments. */
458         if (skb_has_frag_list(head)) {
459                 struct sk_buff *clone;
460                 int i, plen = 0;
461
462                 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
463                         goto out_oom;
464                 clone->next = head->next;
465                 head->next = clone;
466                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
467                 skb_frag_list_init(head);
468                 for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
469                         plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
470                 clone->len = clone->data_len = head->data_len - plen;
471                 head->data_len -= clone->len;
472                 head->len -= clone->len;
473                 clone->csum = 0;
474                 clone->ip_summed = head->ip_summed;
475                 atomic_add(clone->truesize, &fq->q.net->mem);
476         }
477
478         /* We have to remove fragment header from datagram and to relocate
479          * header in order to calculate ICV correctly. */
480         nhoff = fq->nhoffset;
481         skb_network_header(head)[nhoff] = skb_transport_header(head)[0];
482         memmove(head->head + sizeof(struct frag_hdr), head->head,
483                 (head->data - head->head) - sizeof(struct frag_hdr));
484         head->mac_header += sizeof(struct frag_hdr);
485         head->network_header += sizeof(struct frag_hdr);
486
487         skb_shinfo(head)->frag_list = head->next;
488         skb_reset_transport_header(head);
489         skb_push(head, head->data - skb_network_header(head));
490
491         for (fp=head->next; fp; fp = fp->next) {
492                 head->data_len += fp->len;
493                 head->len += fp->len;
494                 if (head->ip_summed != fp->ip_summed)
495                         head->ip_summed = CHECKSUM_NONE;
496                 else if (head->ip_summed == CHECKSUM_COMPLETE)
497                         head->csum = csum_add(head->csum, fp->csum);
498                 head->truesize += fp->truesize;
499         }
500         atomic_sub(head->truesize, &fq->q.net->mem);
501
502         head->next = NULL;
503         head->dev = dev;
504         head->tstamp = fq->q.stamp;
505         ipv6_hdr(head)->payload_len = htons(payload_len);
506         IP6CB(head)->nhoff = nhoff;
507
508         /* Yes, and fold redundant checksum back. 8) */
509         if (head->ip_summed == CHECKSUM_COMPLETE)
510                 head->csum = csum_partial(skb_network_header(head),
511                                           skb_network_header_len(head),
512                                           head->csum);
513
514         rcu_read_lock();
515         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
516         rcu_read_unlock();
517         fq->q.fragments = NULL;
518         fq->q.fragments_tail = NULL;
519         return 1;
520
521 out_oversize:
522         if (net_ratelimit())
523                 printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len);
524         goto out_fail;
525 out_oom:
526         if (net_ratelimit())
527                 printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n");
528 out_fail:
529         rcu_read_lock();
530         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
531         rcu_read_unlock();
532         return -1;
533 }
534
535 static int ipv6_frag_rcv(struct sk_buff *skb)
536 {
537         struct frag_hdr *fhdr;
538         struct frag_queue *fq;
539         const struct ipv6hdr *hdr = ipv6_hdr(skb);
540         struct net *net = dev_net(skb_dst(skb)->dev);
541
542         IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS);
543
544         /* Jumbo payload inhibits frag. header */
545         if (hdr->payload_len==0)
546                 goto fail_hdr;
547
548         if (!pskb_may_pull(skb, (skb_transport_offset(skb) +
549                                  sizeof(struct frag_hdr))))
550                 goto fail_hdr;
551
552         hdr = ipv6_hdr(skb);
553         fhdr = (struct frag_hdr *)skb_transport_header(skb);
554
555         if (!(fhdr->frag_off & htons(0xFFF9))) {
556                 /* It is not a fragmented frame */
557                 skb->transport_header += sizeof(struct frag_hdr);
558                 IP6_INC_STATS_BH(net,
559                                  ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS);
560
561                 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb);
562                 return 1;
563         }
564
565         if (atomic_read(&net->ipv6.frags.mem) > net->ipv6.frags.high_thresh)
566                 ip6_evictor(net, ip6_dst_idev(skb_dst(skb)));
567
568         fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr);
569         if (fq != NULL) {
570                 int ret;
571
572                 spin_lock(&fq->q.lock);
573
574                 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
575
576                 spin_unlock(&fq->q.lock);
577                 fq_put(fq);
578                 return ret;
579         }
580
581         IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS);
582         kfree_skb(skb);
583         return -1;
584
585 fail_hdr:
586         IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS);
587         icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb));
588         return -1;
589 }
590
591 static const struct inet6_protocol frag_protocol =
592 {
593         .handler        =       ipv6_frag_rcv,
594         .flags          =       INET6_PROTO_NOPOLICY,
595 };
596
597 #ifdef CONFIG_SYSCTL
598 static struct ctl_table ip6_frags_ns_ctl_table[] = {
599         {
600                 .procname       = "ip6frag_high_thresh",
601                 .data           = &init_net.ipv6.frags.high_thresh,
602                 .maxlen         = sizeof(int),
603                 .mode           = 0644,
604                 .proc_handler   = proc_dointvec
605         },
606         {
607                 .procname       = "ip6frag_low_thresh",
608                 .data           = &init_net.ipv6.frags.low_thresh,
609                 .maxlen         = sizeof(int),
610                 .mode           = 0644,
611                 .proc_handler   = proc_dointvec
612         },
613         {
614                 .procname       = "ip6frag_time",
615                 .data           = &init_net.ipv6.frags.timeout,
616                 .maxlen         = sizeof(int),
617                 .mode           = 0644,
618                 .proc_handler   = proc_dointvec_jiffies,
619         },
620         { }
621 };
622
623 static struct ctl_table ip6_frags_ctl_table[] = {
624         {
625                 .procname       = "ip6frag_secret_interval",
626                 .data           = &ip6_frags.secret_interval,
627                 .maxlen         = sizeof(int),
628                 .mode           = 0644,
629                 .proc_handler   = proc_dointvec_jiffies,
630         },
631         { }
632 };
633
634 static int __net_init ip6_frags_ns_sysctl_register(struct net *net)
635 {
636         struct ctl_table *table;
637         struct ctl_table_header *hdr;
638
639         table = ip6_frags_ns_ctl_table;
640         if (!net_eq(net, &init_net)) {
641                 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL);
642                 if (table == NULL)
643                         goto err_alloc;
644
645                 table[0].data = &net->ipv6.frags.high_thresh;
646                 table[1].data = &net->ipv6.frags.low_thresh;
647                 table[2].data = &net->ipv6.frags.timeout;
648         }
649
650         hdr = register_net_sysctl_table(net, net_ipv6_ctl_path, table);
651         if (hdr == NULL)
652                 goto err_reg;
653
654         net->ipv6.sysctl.frags_hdr = hdr;
655         return 0;
656
657 err_reg:
658         if (!net_eq(net, &init_net))
659                 kfree(table);
660 err_alloc:
661         return -ENOMEM;
662 }
663
664 static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net)
665 {
666         struct ctl_table *table;
667
668         table = net->ipv6.sysctl.frags_hdr->ctl_table_arg;
669         unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr);
670         if (!net_eq(net, &init_net))
671                 kfree(table);
672 }
673
674 static struct ctl_table_header *ip6_ctl_header;
675
676 static int ip6_frags_sysctl_register(void)
677 {
678         ip6_ctl_header = register_net_sysctl_rotable(net_ipv6_ctl_path,
679                         ip6_frags_ctl_table);
680         return ip6_ctl_header == NULL ? -ENOMEM : 0;
681 }
682
683 static void ip6_frags_sysctl_unregister(void)
684 {
685         unregister_net_sysctl_table(ip6_ctl_header);
686 }
687 #else
688 static inline int ip6_frags_ns_sysctl_register(struct net *net)
689 {
690         return 0;
691 }
692
693 static inline void ip6_frags_ns_sysctl_unregister(struct net *net)
694 {
695 }
696
697 static inline int ip6_frags_sysctl_register(void)
698 {
699         return 0;
700 }
701
702 static inline void ip6_frags_sysctl_unregister(void)
703 {
704 }
705 #endif
706
707 static int __net_init ipv6_frags_init_net(struct net *net)
708 {
709         net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH;
710         net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH;
711         net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT;
712
713         inet_frags_init_net(&net->ipv6.frags);
714
715         return ip6_frags_ns_sysctl_register(net);
716 }
717
718 static void __net_exit ipv6_frags_exit_net(struct net *net)
719 {
720         ip6_frags_ns_sysctl_unregister(net);
721         inet_frags_exit_net(&net->ipv6.frags, &ip6_frags);
722 }
723
724 static struct pernet_operations ip6_frags_ops = {
725         .init = ipv6_frags_init_net,
726         .exit = ipv6_frags_exit_net,
727 };
728
729 int __init ipv6_frag_init(void)
730 {
731         int ret;
732
733         ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT);
734         if (ret)
735                 goto out;
736
737         ret = ip6_frags_sysctl_register();
738         if (ret)
739                 goto err_sysctl;
740
741         ret = register_pernet_subsys(&ip6_frags_ops);
742         if (ret)
743                 goto err_pernet;
744
745         ip6_frags.hashfn = ip6_hashfn;
746         ip6_frags.constructor = ip6_frag_init;
747         ip6_frags.destructor = NULL;
748         ip6_frags.skb_free = NULL;
749         ip6_frags.qsize = sizeof(struct frag_queue);
750         ip6_frags.match = ip6_frag_match;
751         ip6_frags.frag_expire = ip6_frag_expire;
752         ip6_frags.secret_interval = 10 * 60 * HZ;
753         inet_frags_init(&ip6_frags);
754 out:
755         return ret;
756
757 err_pernet:
758         ip6_frags_sysctl_unregister();
759 err_sysctl:
760         inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
761         goto out;
762 }
763
764 void ipv6_frag_exit(void)
765 {
766         inet_frags_fini(&ip6_frags);
767         ip6_frags_sysctl_unregister();
768         unregister_pernet_subsys(&ip6_frags_ops);
769         inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
770 }