tcp: account SYN-ACK timeouts & retransmissions
[linux-3.10.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         u32                     user;
76         struct in6_addr         saddr;
77         struct in6_addr         daddr;
78
79         int                     iif;
80         unsigned int            csum;
81         __u16                   nhoffset;
82 };
83
84 static struct inet_frags ip6_frags;
85
86 int ip6_frag_nqueues(struct net *net)
87 {
88         return net->ipv6.frags.nqueues;
89 }
90
91 int ip6_frag_mem(struct net *net)
92 {
93         return atomic_read(&net->ipv6.frags.mem);
94 }
95
96 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
97                           struct net_device *dev);
98
99 /*
100  * callers should be careful not to use the hash value outside the ipfrag_lock
101  * as doing so could race with ipfrag_hash_rnd being recalculated.
102  */
103 unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
104                              const struct in6_addr *daddr, u32 rnd)
105 {
106         u32 a, b, c;
107
108         a = (__force u32)saddr->s6_addr32[0];
109         b = (__force u32)saddr->s6_addr32[1];
110         c = (__force u32)saddr->s6_addr32[2];
111
112         a += JHASH_GOLDEN_RATIO;
113         b += JHASH_GOLDEN_RATIO;
114         c += rnd;
115         __jhash_mix(a, b, c);
116
117         a += (__force u32)saddr->s6_addr32[3];
118         b += (__force u32)daddr->s6_addr32[0];
119         c += (__force u32)daddr->s6_addr32[1];
120         __jhash_mix(a, b, c);
121
122         a += (__force u32)daddr->s6_addr32[2];
123         b += (__force u32)daddr->s6_addr32[3];
124         c += (__force u32)id;
125         __jhash_mix(a, b, c);
126
127         return c & (INETFRAGS_HASHSZ - 1);
128 }
129 EXPORT_SYMBOL_GPL(inet6_hash_frag);
130
131 static unsigned int ip6_hashfn(struct inet_frag_queue *q)
132 {
133         struct frag_queue *fq;
134
135         fq = container_of(q, struct frag_queue, q);
136         return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr, ip6_frags.rnd);
137 }
138
139 int ip6_frag_match(struct inet_frag_queue *q, void *a)
140 {
141         struct frag_queue *fq;
142         struct ip6_create_arg *arg = a;
143
144         fq = container_of(q, struct frag_queue, q);
145         return (fq->id == arg->id && fq->user == arg->user &&
146                         ipv6_addr_equal(&fq->saddr, arg->src) &&
147                         ipv6_addr_equal(&fq->daddr, arg->dst));
148 }
149 EXPORT_SYMBOL(ip6_frag_match);
150
151 /* Memory Tracking Functions. */
152 static inline void frag_kfree_skb(struct netns_frags *nf,
153                 struct sk_buff *skb, int *work)
154 {
155         if (work)
156                 *work -= skb->truesize;
157         atomic_sub(skb->truesize, &nf->mem);
158         kfree_skb(skb);
159 }
160
161 void ip6_frag_init(struct inet_frag_queue *q, void *a)
162 {
163         struct frag_queue *fq = container_of(q, struct frag_queue, q);
164         struct ip6_create_arg *arg = a;
165
166         fq->id = arg->id;
167         fq->user = arg->user;
168         ipv6_addr_copy(&fq->saddr, arg->src);
169         ipv6_addr_copy(&fq->daddr, arg->dst);
170 }
171 EXPORT_SYMBOL(ip6_frag_init);
172
173 /* Destruction primitives. */
174
175 static __inline__ void fq_put(struct frag_queue *fq)
176 {
177         inet_frag_put(&fq->q, &ip6_frags);
178 }
179
180 /* Kill fq entry. It is not destroyed immediately,
181  * because caller (and someone more) holds reference count.
182  */
183 static __inline__ void fq_kill(struct frag_queue *fq)
184 {
185         inet_frag_kill(&fq->q, &ip6_frags);
186 }
187
188 static void ip6_evictor(struct net *net, struct inet6_dev *idev)
189 {
190         int evicted;
191
192         evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags);
193         if (evicted)
194                 IP6_ADD_STATS_BH(net, idev, IPSTATS_MIB_REASMFAILS, evicted);
195 }
196
197 static void ip6_frag_expire(unsigned long data)
198 {
199         struct frag_queue *fq;
200         struct net_device *dev = NULL;
201         struct net *net;
202
203         fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
204
205         spin_lock(&fq->q.lock);
206
207         if (fq->q.last_in & INET_FRAG_COMPLETE)
208                 goto out;
209
210         fq_kill(fq);
211
212         net = container_of(fq->q.net, struct net, ipv6.frags);
213         rcu_read_lock();
214         dev = dev_get_by_index_rcu(net, fq->iif);
215         if (!dev)
216                 goto out_rcu_unlock;
217
218         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
219         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
220
221         /* Don't send error if the first segment did not arrive. */
222         if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments)
223                 goto out_rcu_unlock;
224
225         /*
226            But use as source device on which LAST ARRIVED
227            segment was received. And do not use fq->dev
228            pointer directly, device might already disappeared.
229          */
230         fq->q.fragments->dev = dev;
231         icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0, dev);
232 out_rcu_unlock:
233         rcu_read_unlock();
234 out:
235         spin_unlock(&fq->q.lock);
236         fq_put(fq);
237 }
238
239 static __inline__ struct frag_queue *
240 fq_find(struct net *net, __be32 id, struct in6_addr *src, struct in6_addr *dst,
241         struct inet6_dev *idev)
242 {
243         struct inet_frag_queue *q;
244         struct ip6_create_arg arg;
245         unsigned int hash;
246
247         arg.id = id;
248         arg.user = IP6_DEFRAG_LOCAL_DELIVER;
249         arg.src = src;
250         arg.dst = dst;
251
252         read_lock(&ip6_frags.lock);
253         hash = inet6_hash_frag(id, src, dst, ip6_frags.rnd);
254
255         q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash);
256         if (q == NULL)
257                 goto oom;
258
259         return container_of(q, struct frag_queue, q);
260
261 oom:
262         IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_REASMFAILS);
263         return NULL;
264 }
265
266 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
267                            struct frag_hdr *fhdr, int nhoff)
268 {
269         struct sk_buff *prev, *next;
270         struct net_device *dev;
271         int offset, end;
272         struct net *net = dev_net(skb_dst(skb)->dev);
273
274         if (fq->q.last_in & INET_FRAG_COMPLETE)
275                 goto err;
276
277         offset = ntohs(fhdr->frag_off) & ~0x7;
278         end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
279                         ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
280
281         if ((unsigned int)end > IPV6_MAXPLEN) {
282                 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
283                                  IPSTATS_MIB_INHDRERRORS);
284                 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
285                                   ((u8 *)&fhdr->frag_off -
286                                    skb_network_header(skb)));
287                 return -1;
288         }
289
290         if (skb->ip_summed == CHECKSUM_COMPLETE) {
291                 const unsigned char *nh = skb_network_header(skb);
292                 skb->csum = csum_sub(skb->csum,
293                                      csum_partial(nh, (u8 *)(fhdr + 1) - nh,
294                                                   0));
295         }
296
297         /* Is this the final fragment? */
298         if (!(fhdr->frag_off & htons(IP6_MF))) {
299                 /* If we already have some bits beyond end
300                  * or have different end, the segment is corrupted.
301                  */
302                 if (end < fq->q.len ||
303                     ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len))
304                         goto err;
305                 fq->q.last_in |= INET_FRAG_LAST_IN;
306                 fq->q.len = end;
307         } else {
308                 /* Check if the fragment is rounded to 8 bytes.
309                  * Required by the RFC.
310                  */
311                 if (end & 0x7) {
312                         /* RFC2460 says always send parameter problem in
313                          * this case. -DaveM
314                          */
315                         IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
316                                          IPSTATS_MIB_INHDRERRORS);
317                         icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
318                                           offsetof(struct ipv6hdr, payload_len));
319                         return -1;
320                 }
321                 if (end > fq->q.len) {
322                         /* Some bits beyond end -> corruption. */
323                         if (fq->q.last_in & INET_FRAG_LAST_IN)
324                                 goto err;
325                         fq->q.len = end;
326                 }
327         }
328
329         if (end == offset)
330                 goto err;
331
332         /* Point into the IP datagram 'data' part. */
333         if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
334                 goto err;
335
336         if (pskb_trim_rcsum(skb, end - offset))
337                 goto err;
338
339         /* Find out which fragments are in front and at the back of us
340          * in the chain of fragments so far.  We must know where to put
341          * this fragment, right?
342          */
343         prev = NULL;
344         for(next = fq->q.fragments; next != NULL; next = next->next) {
345                 if (FRAG6_CB(next)->offset >= offset)
346                         break;  /* bingo! */
347                 prev = next;
348         }
349
350         /* We found where to put this one.  Check for overlap with
351          * preceding fragment, and, if needed, align things so that
352          * any overlaps are eliminated.
353          */
354         if (prev) {
355                 int i = (FRAG6_CB(prev)->offset + prev->len) - offset;
356
357                 if (i > 0) {
358                         offset += i;
359                         if (end <= offset)
360                                 goto err;
361                         if (!pskb_pull(skb, i))
362                                 goto err;
363                         if (skb->ip_summed != CHECKSUM_UNNECESSARY)
364                                 skb->ip_summed = CHECKSUM_NONE;
365                 }
366         }
367
368         /* Look for overlap with succeeding segments.
369          * If we can merge fragments, do it.
370          */
371         while (next && FRAG6_CB(next)->offset < end) {
372                 int i = end - FRAG6_CB(next)->offset; /* overlap is 'i' bytes */
373
374                 if (i < next->len) {
375                         /* Eat head of the next overlapped fragment
376                          * and leave the loop. The next ones cannot overlap.
377                          */
378                         if (!pskb_pull(next, i))
379                                 goto err;
380                         FRAG6_CB(next)->offset += i;    /* next fragment */
381                         fq->q.meat -= i;
382                         if (next->ip_summed != CHECKSUM_UNNECESSARY)
383                                 next->ip_summed = CHECKSUM_NONE;
384                         break;
385                 } else {
386                         struct sk_buff *free_it = next;
387
388                         /* Old fragment is completely overridden with
389                          * new one drop it.
390                          */
391                         next = next->next;
392
393                         if (prev)
394                                 prev->next = next;
395                         else
396                                 fq->q.fragments = next;
397
398                         fq->q.meat -= free_it->len;
399                         frag_kfree_skb(fq->q.net, free_it, NULL);
400                 }
401         }
402
403         FRAG6_CB(skb)->offset = offset;
404
405         /* Insert this fragment in the chain of fragments. */
406         skb->next = next;
407         if (prev)
408                 prev->next = skb;
409         else
410                 fq->q.fragments = skb;
411
412         dev = skb->dev;
413         if (dev) {
414                 fq->iif = dev->ifindex;
415                 skb->dev = NULL;
416         }
417         fq->q.stamp = skb->tstamp;
418         fq->q.meat += skb->len;
419         atomic_add(skb->truesize, &fq->q.net->mem);
420
421         /* The first fragment.
422          * nhoffset is obtained from the first fragment, of course.
423          */
424         if (offset == 0) {
425                 fq->nhoffset = nhoff;
426                 fq->q.last_in |= INET_FRAG_FIRST_IN;
427         }
428
429         if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
430             fq->q.meat == fq->q.len)
431                 return ip6_frag_reasm(fq, prev, dev);
432
433         write_lock(&ip6_frags.lock);
434         list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list);
435         write_unlock(&ip6_frags.lock);
436         return -1;
437
438 err:
439         IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
440                       IPSTATS_MIB_REASMFAILS);
441         kfree_skb(skb);
442         return -1;
443 }
444
445 /*
446  *      Check if this packet is complete.
447  *      Returns NULL on failure by any reason, and pointer
448  *      to current nexthdr field in reassembled frame.
449  *
450  *      It is called with locked fq, and caller must check that
451  *      queue is eligible for reassembly i.e. it is not COMPLETE,
452  *      the last and the first frames arrived and all the bits are here.
453  */
454 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
455                           struct net_device *dev)
456 {
457         struct net *net = container_of(fq->q.net, struct net, ipv6.frags);
458         struct sk_buff *fp, *head = fq->q.fragments;
459         int    payload_len;
460         unsigned int nhoff;
461
462         fq_kill(fq);
463
464         /* Make the one we just received the head. */
465         if (prev) {
466                 head = prev->next;
467                 fp = skb_clone(head, GFP_ATOMIC);
468
469                 if (!fp)
470                         goto out_oom;
471
472                 fp->next = head->next;
473                 prev->next = fp;
474
475                 skb_morph(head, fq->q.fragments);
476                 head->next = fq->q.fragments->next;
477
478                 kfree_skb(fq->q.fragments);
479                 fq->q.fragments = head;
480         }
481
482         WARN_ON(head == NULL);
483         WARN_ON(FRAG6_CB(head)->offset != 0);
484
485         /* Unfragmented part is taken from the first segment. */
486         payload_len = ((head->data - skb_network_header(head)) -
487                        sizeof(struct ipv6hdr) + fq->q.len -
488                        sizeof(struct frag_hdr));
489         if (payload_len > IPV6_MAXPLEN)
490                 goto out_oversize;
491
492         /* Head of list must not be cloned. */
493         if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
494                 goto out_oom;
495
496         /* If the first fragment is fragmented itself, we split
497          * it to two chunks: the first with data and paged part
498          * and the second, holding only fragments. */
499         if (skb_has_frags(head)) {
500                 struct sk_buff *clone;
501                 int i, plen = 0;
502
503                 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
504                         goto out_oom;
505                 clone->next = head->next;
506                 head->next = clone;
507                 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
508                 skb_frag_list_init(head);
509                 for (i=0; i<skb_shinfo(head)->nr_frags; i++)
510                         plen += skb_shinfo(head)->frags[i].size;
511                 clone->len = clone->data_len = head->data_len - plen;
512                 head->data_len -= clone->len;
513                 head->len -= clone->len;
514                 clone->csum = 0;
515                 clone->ip_summed = head->ip_summed;
516                 atomic_add(clone->truesize, &fq->q.net->mem);
517         }
518
519         /* We have to remove fragment header from datagram and to relocate
520          * header in order to calculate ICV correctly. */
521         nhoff = fq->nhoffset;
522         skb_network_header(head)[nhoff] = skb_transport_header(head)[0];
523         memmove(head->head + sizeof(struct frag_hdr), head->head,
524                 (head->data - head->head) - sizeof(struct frag_hdr));
525         head->mac_header += sizeof(struct frag_hdr);
526         head->network_header += sizeof(struct frag_hdr);
527
528         skb_shinfo(head)->frag_list = head->next;
529         skb_reset_transport_header(head);
530         skb_push(head, head->data - skb_network_header(head));
531         atomic_sub(head->truesize, &fq->q.net->mem);
532
533         for (fp=head->next; fp; fp = fp->next) {
534                 head->data_len += fp->len;
535                 head->len += fp->len;
536                 if (head->ip_summed != fp->ip_summed)
537                         head->ip_summed = CHECKSUM_NONE;
538                 else if (head->ip_summed == CHECKSUM_COMPLETE)
539                         head->csum = csum_add(head->csum, fp->csum);
540                 head->truesize += fp->truesize;
541                 atomic_sub(fp->truesize, &fq->q.net->mem);
542         }
543
544         head->next = NULL;
545         head->dev = dev;
546         head->tstamp = fq->q.stamp;
547         ipv6_hdr(head)->payload_len = htons(payload_len);
548         IP6CB(head)->nhoff = nhoff;
549
550         /* Yes, and fold redundant checksum back. 8) */
551         if (head->ip_summed == CHECKSUM_COMPLETE)
552                 head->csum = csum_partial(skb_network_header(head),
553                                           skb_network_header_len(head),
554                                           head->csum);
555
556         rcu_read_lock();
557         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
558         rcu_read_unlock();
559         fq->q.fragments = NULL;
560         return 1;
561
562 out_oversize:
563         if (net_ratelimit())
564                 printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len);
565         goto out_fail;
566 out_oom:
567         if (net_ratelimit())
568                 printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n");
569 out_fail:
570         rcu_read_lock();
571         IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
572         rcu_read_unlock();
573         return -1;
574 }
575
576 static int ipv6_frag_rcv(struct sk_buff *skb)
577 {
578         struct frag_hdr *fhdr;
579         struct frag_queue *fq;
580         struct ipv6hdr *hdr = ipv6_hdr(skb);
581         struct net *net = dev_net(skb_dst(skb)->dev);
582
583         IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS);
584
585         /* Jumbo payload inhibits frag. header */
586         if (hdr->payload_len==0)
587                 goto fail_hdr;
588
589         if (!pskb_may_pull(skb, (skb_transport_offset(skb) +
590                                  sizeof(struct frag_hdr))))
591                 goto fail_hdr;
592
593         hdr = ipv6_hdr(skb);
594         fhdr = (struct frag_hdr *)skb_transport_header(skb);
595
596         if (!(fhdr->frag_off & htons(0xFFF9))) {
597                 /* It is not a fragmented frame */
598                 skb->transport_header += sizeof(struct frag_hdr);
599                 IP6_INC_STATS_BH(net,
600                                  ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS);
601
602                 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb);
603                 return 1;
604         }
605
606         if (atomic_read(&net->ipv6.frags.mem) > net->ipv6.frags.high_thresh)
607                 ip6_evictor(net, ip6_dst_idev(skb_dst(skb)));
608
609         if ((fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr,
610                           ip6_dst_idev(skb_dst(skb)))) != NULL) {
611                 int ret;
612
613                 spin_lock(&fq->q.lock);
614
615                 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
616
617                 spin_unlock(&fq->q.lock);
618                 fq_put(fq);
619                 return ret;
620         }
621
622         IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS);
623         kfree_skb(skb);
624         return -1;
625
626 fail_hdr:
627         IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS);
628         icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb));
629         return -1;
630 }
631
632 static const struct inet6_protocol frag_protocol =
633 {
634         .handler        =       ipv6_frag_rcv,
635         .flags          =       INET6_PROTO_NOPOLICY,
636 };
637
638 #ifdef CONFIG_SYSCTL
639 static struct ctl_table ip6_frags_ns_ctl_table[] = {
640         {
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                 .procname       = "ip6frag_low_thresh",
649                 .data           = &init_net.ipv6.frags.low_thresh,
650                 .maxlen         = sizeof(int),
651                 .mode           = 0644,
652                 .proc_handler   = proc_dointvec
653         },
654         {
655                 .procname       = "ip6frag_time",
656                 .data           = &init_net.ipv6.frags.timeout,
657                 .maxlen         = sizeof(int),
658                 .mode           = 0644,
659                 .proc_handler   = proc_dointvec_jiffies,
660         },
661         { }
662 };
663
664 static struct ctl_table ip6_frags_ctl_table[] = {
665         {
666                 .procname       = "ip6frag_secret_interval",
667                 .data           = &ip6_frags.secret_interval,
668                 .maxlen         = sizeof(int),
669                 .mode           = 0644,
670                 .proc_handler   = proc_dointvec_jiffies,
671         },
672         { }
673 };
674
675 static int ip6_frags_ns_sysctl_register(struct net *net)
676 {
677         struct ctl_table *table;
678         struct ctl_table_header *hdr;
679
680         table = ip6_frags_ns_ctl_table;
681         if (!net_eq(net, &init_net)) {
682                 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL);
683                 if (table == NULL)
684                         goto err_alloc;
685
686                 table[0].data = &net->ipv6.frags.high_thresh;
687                 table[1].data = &net->ipv6.frags.low_thresh;
688                 table[2].data = &net->ipv6.frags.timeout;
689         }
690
691         hdr = register_net_sysctl_table(net, net_ipv6_ctl_path, table);
692         if (hdr == NULL)
693                 goto err_reg;
694
695         net->ipv6.sysctl.frags_hdr = hdr;
696         return 0;
697
698 err_reg:
699         if (!net_eq(net, &init_net))
700                 kfree(table);
701 err_alloc:
702         return -ENOMEM;
703 }
704
705 static void ip6_frags_ns_sysctl_unregister(struct net *net)
706 {
707         struct ctl_table *table;
708
709         table = net->ipv6.sysctl.frags_hdr->ctl_table_arg;
710         unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr);
711         if (!net_eq(net, &init_net))
712                 kfree(table);
713 }
714
715 static struct ctl_table_header *ip6_ctl_header;
716
717 static int ip6_frags_sysctl_register(void)
718 {
719         ip6_ctl_header = register_net_sysctl_rotable(net_ipv6_ctl_path,
720                         ip6_frags_ctl_table);
721         return ip6_ctl_header == NULL ? -ENOMEM : 0;
722 }
723
724 static void ip6_frags_sysctl_unregister(void)
725 {
726         unregister_net_sysctl_table(ip6_ctl_header);
727 }
728 #else
729 static inline int ip6_frags_ns_sysctl_register(struct net *net)
730 {
731         return 0;
732 }
733
734 static inline void ip6_frags_ns_sysctl_unregister(struct net *net)
735 {
736 }
737
738 static inline int ip6_frags_sysctl_register(void)
739 {
740         return 0;
741 }
742
743 static inline void ip6_frags_sysctl_unregister(void)
744 {
745 }
746 #endif
747
748 static int ipv6_frags_init_net(struct net *net)
749 {
750         net->ipv6.frags.high_thresh = 256 * 1024;
751         net->ipv6.frags.low_thresh = 192 * 1024;
752         net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT;
753
754         inet_frags_init_net(&net->ipv6.frags);
755
756         return ip6_frags_ns_sysctl_register(net);
757 }
758
759 static void ipv6_frags_exit_net(struct net *net)
760 {
761         ip6_frags_ns_sysctl_unregister(net);
762         inet_frags_exit_net(&net->ipv6.frags, &ip6_frags);
763 }
764
765 static struct pernet_operations ip6_frags_ops = {
766         .init = ipv6_frags_init_net,
767         .exit = ipv6_frags_exit_net,
768 };
769
770 int __init ipv6_frag_init(void)
771 {
772         int ret;
773
774         ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT);
775         if (ret)
776                 goto out;
777
778         ret = ip6_frags_sysctl_register();
779         if (ret)
780                 goto err_sysctl;
781
782         ret = register_pernet_subsys(&ip6_frags_ops);
783         if (ret)
784                 goto err_pernet;
785
786         ip6_frags.hashfn = ip6_hashfn;
787         ip6_frags.constructor = ip6_frag_init;
788         ip6_frags.destructor = NULL;
789         ip6_frags.skb_free = NULL;
790         ip6_frags.qsize = sizeof(struct frag_queue);
791         ip6_frags.match = ip6_frag_match;
792         ip6_frags.frag_expire = ip6_frag_expire;
793         ip6_frags.secret_interval = 10 * 60 * HZ;
794         inet_frags_init(&ip6_frags);
795 out:
796         return ret;
797
798 err_pernet:
799         ip6_frags_sysctl_unregister();
800 err_sysctl:
801         inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
802         goto out;
803 }
804
805 void ipv6_frag_exit(void)
806 {
807         inet_frags_fini(&ip6_frags);
808         ip6_frags_sysctl_unregister();
809         unregister_pernet_subsys(&ip6_frags_ops);
810         inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
811 }