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
30 #define pr_fmt(fmt) "IPv6: " fmt
31
32 #include <linux/errno.h>
33 #include <linux/types.h>
34 #include <linux/string.h>
35 #include <linux/socket.h>
36 #include <linux/sockios.h>
37 #include <linux/jiffies.h>
38 #include <linux/net.h>
39 #include <linux/list.h>
40 #include <linux/netdevice.h>
41 #include <linux/in6.h>
42 #include <linux/ipv6.h>
43 #include <linux/icmpv6.h>
44 #include <linux/random.h>
45 #include <linux/jhash.h>
46 #include <linux/skbuff.h>
47 #include <linux/slab.h>
48 #include <linux/export.h>
49
50 #include <net/sock.h>
51 #include <net/snmp.h>
52
53 #include <net/ipv6.h>
54 #include <net/ip6_route.h>
55 #include <net/protocol.h>
56 #include <net/transp_v6.h>
57 #include <net/rawv6.h>
58 #include <net/ndisc.h>
59 #include <net/addrconf.h>
60 #include <net/inet_frag.h>
61
62 struct ip6frag_skb_cb
63 {
64 struct inet6_skb_parm h;
65 int offset;
66 };
67
68 #define FRAG6_CB(skb) ((struct ip6frag_skb_cb*)((skb)->cb))
69
70
71 /*
72 * Equivalent of ipv4 struct ipq
73 */
74
75 struct frag_queue
76 {
77 struct inet_frag_queue q;
78
79 __be32 id; /* fragment id */
80 u32 user;
81 struct in6_addr saddr;
82 struct in6_addr daddr;
83
84 int iif;
85 unsigned int csum;
86 __u16 nhoffset;
87 };
88
89 static struct inet_frags ip6_frags;
90
ip6_frag_nqueues(struct net * net)91 int ip6_frag_nqueues(struct net *net)
92 {
93 return net->ipv6.frags.nqueues;
94 }
95
ip6_frag_mem(struct net * net)96 int ip6_frag_mem(struct net *net)
97 {
98 return atomic_read(&net->ipv6.frags.mem);
99 }
100
101 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
102 struct net_device *dev);
103
104 /*
105 * callers should be careful not to use the hash value outside the ipfrag_lock
106 * as doing so could race with ipfrag_hash_rnd being recalculated.
107 */
inet6_hash_frag(__be32 id,const struct in6_addr * saddr,const struct in6_addr * daddr,u32 rnd)108 unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
109 const struct in6_addr *daddr, u32 rnd)
110 {
111 u32 c;
112
113 c = jhash_3words((__force u32)saddr->s6_addr32[0],
114 (__force u32)saddr->s6_addr32[1],
115 (__force u32)saddr->s6_addr32[2],
116 rnd);
117
118 c = jhash_3words((__force u32)saddr->s6_addr32[3],
119 (__force u32)daddr->s6_addr32[0],
120 (__force u32)daddr->s6_addr32[1],
121 c);
122
123 c = jhash_3words((__force u32)daddr->s6_addr32[2],
124 (__force u32)daddr->s6_addr32[3],
125 (__force u32)id,
126 c);
127
128 return c & (INETFRAGS_HASHSZ - 1);
129 }
130 EXPORT_SYMBOL_GPL(inet6_hash_frag);
131
ip6_hashfn(struct inet_frag_queue * q)132 static unsigned int ip6_hashfn(struct inet_frag_queue *q)
133 {
134 struct frag_queue *fq;
135
136 fq = container_of(q, struct frag_queue, q);
137 return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr, ip6_frags.rnd);
138 }
139
ip6_frag_match(struct inet_frag_queue * q,void * a)140 int ip6_frag_match(struct inet_frag_queue *q, void *a)
141 {
142 struct frag_queue *fq;
143 struct ip6_create_arg *arg = a;
144
145 fq = container_of(q, struct frag_queue, q);
146 return (fq->id == arg->id && fq->user == arg->user &&
147 ipv6_addr_equal(&fq->saddr, arg->src) &&
148 ipv6_addr_equal(&fq->daddr, arg->dst));
149 }
150 EXPORT_SYMBOL(ip6_frag_match);
151
ip6_frag_init(struct inet_frag_queue * q,void * a)152 void ip6_frag_init(struct inet_frag_queue *q, void *a)
153 {
154 struct frag_queue *fq = container_of(q, struct frag_queue, q);
155 struct ip6_create_arg *arg = a;
156
157 fq->id = arg->id;
158 fq->user = arg->user;
159 fq->saddr = *arg->src;
160 fq->daddr = *arg->dst;
161 }
162 EXPORT_SYMBOL(ip6_frag_init);
163
164 /* Destruction primitives. */
165
fq_put(struct frag_queue * fq)166 static __inline__ void fq_put(struct frag_queue *fq)
167 {
168 inet_frag_put(&fq->q, &ip6_frags);
169 }
170
171 /* Kill fq entry. It is not destroyed immediately,
172 * because caller (and someone more) holds reference count.
173 */
fq_kill(struct frag_queue * fq)174 static __inline__ void fq_kill(struct frag_queue *fq)
175 {
176 inet_frag_kill(&fq->q, &ip6_frags);
177 }
178
ip6_evictor(struct net * net,struct inet6_dev * idev)179 static void ip6_evictor(struct net *net, struct inet6_dev *idev)
180 {
181 int evicted;
182
183 evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags);
184 if (evicted)
185 IP6_ADD_STATS_BH(net, idev, IPSTATS_MIB_REASMFAILS, evicted);
186 }
187
ip6_frag_expire(unsigned long data)188 static void ip6_frag_expire(unsigned long data)
189 {
190 struct frag_queue *fq;
191 struct net_device *dev = NULL;
192 struct net *net;
193
194 fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
195
196 spin_lock(&fq->q.lock);
197
198 if (fq->q.last_in & INET_FRAG_COMPLETE)
199 goto out;
200
201 fq_kill(fq);
202
203 net = container_of(fq->q.net, struct net, ipv6.frags);
204 rcu_read_lock();
205 dev = dev_get_by_index_rcu(net, fq->iif);
206 if (!dev)
207 goto out_rcu_unlock;
208
209 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
210 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
211
212 /* Don't send error if the first segment did not arrive. */
213 if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments)
214 goto out_rcu_unlock;
215
216 /*
217 But use as source device on which LAST ARRIVED
218 segment was received. And do not use fq->dev
219 pointer directly, device might already disappeared.
220 */
221 fq->q.fragments->dev = dev;
222 icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
223 out_rcu_unlock:
224 rcu_read_unlock();
225 out:
226 spin_unlock(&fq->q.lock);
227 fq_put(fq);
228 }
229
230 static __inline__ struct frag_queue *
fq_find(struct net * net,__be32 id,const struct in6_addr * src,const struct in6_addr * dst)231 fq_find(struct net *net, __be32 id, const struct in6_addr *src, const struct in6_addr *dst)
232 {
233 struct inet_frag_queue *q;
234 struct ip6_create_arg arg;
235 unsigned int hash;
236
237 arg.id = id;
238 arg.user = IP6_DEFRAG_LOCAL_DELIVER;
239 arg.src = src;
240 arg.dst = dst;
241
242 read_lock(&ip6_frags.lock);
243 hash = inet6_hash_frag(id, src, dst, ip6_frags.rnd);
244
245 q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash);
246 if (IS_ERR_OR_NULL(q)) {
247 inet_frag_maybe_warn_overflow(q, pr_fmt());
248 return NULL;
249 }
250 return container_of(q, struct frag_queue, q);
251 }
252
ip6_frag_queue(struct frag_queue * fq,struct sk_buff * skb,struct frag_hdr * fhdr,int nhoff)253 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
254 struct frag_hdr *fhdr, int nhoff)
255 {
256 struct sk_buff *prev, *next;
257 struct net_device *dev;
258 int offset, end;
259 struct net *net = dev_net(skb_dst(skb)->dev);
260
261 if (fq->q.last_in & INET_FRAG_COMPLETE)
262 goto err;
263
264 offset = ntohs(fhdr->frag_off) & ~0x7;
265 end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
266 ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
267
268 if ((unsigned int)end > IPV6_MAXPLEN) {
269 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
270 IPSTATS_MIB_INHDRERRORS);
271 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
272 ((u8 *)&fhdr->frag_off -
273 skb_network_header(skb)));
274 return -1;
275 }
276
277 if (skb->ip_summed == CHECKSUM_COMPLETE) {
278 const unsigned char *nh = skb_network_header(skb);
279 skb->csum = csum_sub(skb->csum,
280 csum_partial(nh, (u8 *)(fhdr + 1) - nh,
281 0));
282 }
283
284 /* Is this the final fragment? */
285 if (!(fhdr->frag_off & htons(IP6_MF))) {
286 /* If we already have some bits beyond end
287 * or have different end, the segment is corrupted.
288 */
289 if (end < fq->q.len ||
290 ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len))
291 goto err;
292 fq->q.last_in |= INET_FRAG_LAST_IN;
293 fq->q.len = end;
294 } else {
295 /* Check if the fragment is rounded to 8 bytes.
296 * Required by the RFC.
297 */
298 if (end & 0x7) {
299 /* RFC2460 says always send parameter problem in
300 * this case. -DaveM
301 */
302 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
303 IPSTATS_MIB_INHDRERRORS);
304 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
305 offsetof(struct ipv6hdr, payload_len));
306 return -1;
307 }
308 if (end > fq->q.len) {
309 /* Some bits beyond end -> corruption. */
310 if (fq->q.last_in & INET_FRAG_LAST_IN)
311 goto err;
312 fq->q.len = end;
313 }
314 }
315
316 if (end == offset)
317 goto err;
318
319 /* Point into the IP datagram 'data' part. */
320 if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
321 goto err;
322
323 if (pskb_trim_rcsum(skb, end - offset))
324 goto err;
325
326 /* Find out which fragments are in front and at the back of us
327 * in the chain of fragments so far. We must know where to put
328 * this fragment, right?
329 */
330 prev = fq->q.fragments_tail;
331 if (!prev || FRAG6_CB(prev)->offset < offset) {
332 next = NULL;
333 goto found;
334 }
335 prev = NULL;
336 for(next = fq->q.fragments; next != NULL; next = next->next) {
337 if (FRAG6_CB(next)->offset >= offset)
338 break; /* bingo! */
339 prev = next;
340 }
341
342 found:
343 /* RFC5722, Section 4, amended by Errata ID : 3089
344 * When reassembling an IPv6 datagram, if
345 * one or more its constituent fragments is determined to be an
346 * overlapping fragment, the entire datagram (and any constituent
347 * fragments) MUST be silently discarded.
348 */
349
350 /* Check for overlap with preceding fragment. */
351 if (prev &&
352 (FRAG6_CB(prev)->offset + prev->len) > offset)
353 goto discard_fq;
354
355 /* Look for overlap with succeeding segment. */
356 if (next && FRAG6_CB(next)->offset < end)
357 goto discard_fq;
358
359 FRAG6_CB(skb)->offset = offset;
360
361 /* Insert this fragment in the chain of fragments. */
362 skb->next = next;
363 if (!next)
364 fq->q.fragments_tail = skb;
365 if (prev)
366 prev->next = skb;
367 else
368 fq->q.fragments = skb;
369
370 dev = skb->dev;
371 if (dev) {
372 fq->iif = dev->ifindex;
373 skb->dev = NULL;
374 }
375 fq->q.stamp = skb->tstamp;
376 fq->q.meat += skb->len;
377 atomic_add(skb->truesize, &fq->q.net->mem);
378
379 /* The first fragment.
380 * nhoffset is obtained from the first fragment, of course.
381 */
382 if (offset == 0) {
383 fq->nhoffset = nhoff;
384 fq->q.last_in |= INET_FRAG_FIRST_IN;
385 }
386
387 if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
388 fq->q.meat == fq->q.len) {
389 int res;
390 unsigned long orefdst = skb->_skb_refdst;
391
392 skb->_skb_refdst = 0UL;
393 res = ip6_frag_reasm(fq, prev, dev);
394 skb->_skb_refdst = orefdst;
395 return res;
396 }
397
398 skb_dst_drop(skb);
399
400 write_lock(&ip6_frags.lock);
401 list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list);
402 write_unlock(&ip6_frags.lock);
403 return -1;
404
405 discard_fq:
406 fq_kill(fq);
407 err:
408 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
409 IPSTATS_MIB_REASMFAILS);
410 kfree_skb(skb);
411 return -1;
412 }
413
414 /*
415 * Check if this packet is complete.
416 * Returns NULL on failure by any reason, and pointer
417 * to current nexthdr field in reassembled frame.
418 *
419 * It is called with locked fq, and caller must check that
420 * queue is eligible for reassembly i.e. it is not COMPLETE,
421 * the last and the first frames arrived and all the bits are here.
422 */
ip6_frag_reasm(struct frag_queue * fq,struct sk_buff * prev,struct net_device * dev)423 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
424 struct net_device *dev)
425 {
426 struct net *net = container_of(fq->q.net, struct net, ipv6.frags);
427 struct sk_buff *fp, *head = fq->q.fragments;
428 int payload_len;
429 unsigned int nhoff;
430
431 fq_kill(fq);
432
433 /* Make the one we just received the head. */
434 if (prev) {
435 head = prev->next;
436 fp = skb_clone(head, GFP_ATOMIC);
437
438 if (!fp)
439 goto out_oom;
440
441 fp->next = head->next;
442 if (!fp->next)
443 fq->q.fragments_tail = fp;
444 prev->next = fp;
445
446 skb_morph(head, fq->q.fragments);
447 head->next = fq->q.fragments->next;
448
449 kfree_skb(fq->q.fragments);
450 fq->q.fragments = head;
451 }
452
453 WARN_ON(head == NULL);
454 WARN_ON(FRAG6_CB(head)->offset != 0);
455
456 /* Unfragmented part is taken from the first segment. */
457 payload_len = ((head->data - skb_network_header(head)) -
458 sizeof(struct ipv6hdr) + fq->q.len -
459 sizeof(struct frag_hdr));
460 if (payload_len > IPV6_MAXPLEN)
461 goto out_oversize;
462
463 /* Head of list must not be cloned. */
464 if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
465 goto out_oom;
466
467 /* If the first fragment is fragmented itself, we split
468 * it to two chunks: the first with data and paged part
469 * and the second, holding only fragments. */
470 if (skb_has_frag_list(head)) {
471 struct sk_buff *clone;
472 int i, plen = 0;
473
474 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
475 goto out_oom;
476 clone->next = head->next;
477 head->next = clone;
478 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
479 skb_frag_list_init(head);
480 for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
481 plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
482 clone->len = clone->data_len = head->data_len - plen;
483 head->data_len -= clone->len;
484 head->len -= clone->len;
485 clone->csum = 0;
486 clone->ip_summed = head->ip_summed;
487 atomic_add(clone->truesize, &fq->q.net->mem);
488 }
489
490 /* We have to remove fragment header from datagram and to relocate
491 * header in order to calculate ICV correctly. */
492 nhoff = fq->nhoffset;
493 skb_network_header(head)[nhoff] = skb_transport_header(head)[0];
494 memmove(head->head + sizeof(struct frag_hdr), head->head,
495 (head->data - head->head) - sizeof(struct frag_hdr));
496 head->mac_header += sizeof(struct frag_hdr);
497 head->network_header += sizeof(struct frag_hdr);
498
499 skb_shinfo(head)->frag_list = head->next;
500 skb_reset_transport_header(head);
501 skb_push(head, head->data - skb_network_header(head));
502
503 for (fp=head->next; fp; fp = fp->next) {
504 head->data_len += fp->len;
505 head->len += fp->len;
506 if (head->ip_summed != fp->ip_summed)
507 head->ip_summed = CHECKSUM_NONE;
508 else if (head->ip_summed == CHECKSUM_COMPLETE)
509 head->csum = csum_add(head->csum, fp->csum);
510 head->truesize += fp->truesize;
511 }
512 atomic_sub(head->truesize, &fq->q.net->mem);
513
514 head->next = NULL;
515 head->dev = dev;
516 head->tstamp = fq->q.stamp;
517 ipv6_hdr(head)->payload_len = htons(payload_len);
518 IP6CB(head)->nhoff = nhoff;
519 IP6CB(head)->flags |= IP6SKB_FRAGMENTED;
520
521 /* Yes, and fold redundant checksum back. 8) */
522 if (head->ip_summed == CHECKSUM_COMPLETE)
523 head->csum = csum_partial(skb_network_header(head),
524 skb_network_header_len(head),
525 head->csum);
526
527 rcu_read_lock();
528 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
529 rcu_read_unlock();
530 fq->q.fragments = NULL;
531 fq->q.fragments_tail = NULL;
532 return 1;
533
534 out_oversize:
535 if (net_ratelimit())
536 printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len);
537 goto out_fail;
538 out_oom:
539 if (net_ratelimit())
540 printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n");
541 out_fail:
542 rcu_read_lock();
543 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
544 rcu_read_unlock();
545 return -1;
546 }
547
ipv6_frag_rcv(struct sk_buff * skb)548 static int ipv6_frag_rcv(struct sk_buff *skb)
549 {
550 struct frag_hdr *fhdr;
551 struct frag_queue *fq;
552 const struct ipv6hdr *hdr = ipv6_hdr(skb);
553 struct net *net = dev_net(skb_dst(skb)->dev);
554
555 if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED)
556 goto fail_hdr;
557
558 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS);
559
560 /* Jumbo payload inhibits frag. header */
561 if (hdr->payload_len==0)
562 goto fail_hdr;
563
564 if (!pskb_may_pull(skb, (skb_transport_offset(skb) +
565 sizeof(struct frag_hdr))))
566 goto fail_hdr;
567
568 hdr = ipv6_hdr(skb);
569 fhdr = (struct frag_hdr *)skb_transport_header(skb);
570
571 if (!(fhdr->frag_off & htons(0xFFF9))) {
572 /* It is not a fragmented frame */
573 skb->transport_header += sizeof(struct frag_hdr);
574 IP6_INC_STATS_BH(net,
575 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS);
576
577 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb);
578 IP6CB(skb)->flags |= IP6SKB_FRAGMENTED;
579 return 1;
580 }
581
582 if (atomic_read(&net->ipv6.frags.mem) > net->ipv6.frags.high_thresh)
583 ip6_evictor(net, ip6_dst_idev(skb_dst(skb)));
584
585 fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr);
586 if (fq != NULL) {
587 int ret;
588
589 spin_lock(&fq->q.lock);
590
591 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
592
593 spin_unlock(&fq->q.lock);
594 fq_put(fq);
595 return ret;
596 }
597
598 IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS);
599 kfree_skb(skb);
600 return -1;
601
602 fail_hdr:
603 IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INHDRERRORS);
604 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb));
605 return -1;
606 }
607
608 static const struct inet6_protocol frag_protocol =
609 {
610 .handler = ipv6_frag_rcv,
611 .flags = INET6_PROTO_NOPOLICY,
612 };
613
614 #ifdef CONFIG_SYSCTL
615 static struct ctl_table ip6_frags_ns_ctl_table[] = {
616 {
617 .procname = "ip6frag_high_thresh",
618 .data = &init_net.ipv6.frags.high_thresh,
619 .maxlen = sizeof(int),
620 .mode = 0644,
621 .proc_handler = proc_dointvec
622 },
623 {
624 .procname = "ip6frag_low_thresh",
625 .data = &init_net.ipv6.frags.low_thresh,
626 .maxlen = sizeof(int),
627 .mode = 0644,
628 .proc_handler = proc_dointvec
629 },
630 {
631 .procname = "ip6frag_time",
632 .data = &init_net.ipv6.frags.timeout,
633 .maxlen = sizeof(int),
634 .mode = 0644,
635 .proc_handler = proc_dointvec_jiffies,
636 },
637 { }
638 };
639
640 static struct ctl_table ip6_frags_ctl_table[] = {
641 {
642 .procname = "ip6frag_secret_interval",
643 .data = &ip6_frags.secret_interval,
644 .maxlen = sizeof(int),
645 .mode = 0644,
646 .proc_handler = proc_dointvec_jiffies,
647 },
648 { }
649 };
650
ip6_frags_ns_sysctl_register(struct net * net)651 static int __net_init ip6_frags_ns_sysctl_register(struct net *net)
652 {
653 struct ctl_table *table;
654 struct ctl_table_header *hdr;
655
656 table = ip6_frags_ns_ctl_table;
657 if (!net_eq(net, &init_net)) {
658 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL);
659 if (table == NULL)
660 goto err_alloc;
661
662 table[0].data = &net->ipv6.frags.high_thresh;
663 table[1].data = &net->ipv6.frags.low_thresh;
664 table[2].data = &net->ipv6.frags.timeout;
665 }
666
667 hdr = register_net_sysctl_table(net, net_ipv6_ctl_path, table);
668 if (hdr == NULL)
669 goto err_reg;
670
671 net->ipv6.sysctl.frags_hdr = hdr;
672 return 0;
673
674 err_reg:
675 if (!net_eq(net, &init_net))
676 kfree(table);
677 err_alloc:
678 return -ENOMEM;
679 }
680
ip6_frags_ns_sysctl_unregister(struct net * net)681 static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net)
682 {
683 struct ctl_table *table;
684
685 table = net->ipv6.sysctl.frags_hdr->ctl_table_arg;
686 unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr);
687 if (!net_eq(net, &init_net))
688 kfree(table);
689 }
690
691 static struct ctl_table_header *ip6_ctl_header;
692
ip6_frags_sysctl_register(void)693 static int ip6_frags_sysctl_register(void)
694 {
695 ip6_ctl_header = register_net_sysctl_rotable(net_ipv6_ctl_path,
696 ip6_frags_ctl_table);
697 return ip6_ctl_header == NULL ? -ENOMEM : 0;
698 }
699
ip6_frags_sysctl_unregister(void)700 static void ip6_frags_sysctl_unregister(void)
701 {
702 unregister_net_sysctl_table(ip6_ctl_header);
703 }
704 #else
ip6_frags_ns_sysctl_register(struct net * net)705 static inline int ip6_frags_ns_sysctl_register(struct net *net)
706 {
707 return 0;
708 }
709
ip6_frags_ns_sysctl_unregister(struct net * net)710 static inline void ip6_frags_ns_sysctl_unregister(struct net *net)
711 {
712 }
713
ip6_frags_sysctl_register(void)714 static inline int ip6_frags_sysctl_register(void)
715 {
716 return 0;
717 }
718
ip6_frags_sysctl_unregister(void)719 static inline void ip6_frags_sysctl_unregister(void)
720 {
721 }
722 #endif
723
ipv6_frags_init_net(struct net * net)724 static int __net_init ipv6_frags_init_net(struct net *net)
725 {
726 net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH;
727 net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH;
728 net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT;
729
730 inet_frags_init_net(&net->ipv6.frags);
731
732 return ip6_frags_ns_sysctl_register(net);
733 }
734
ipv6_frags_exit_net(struct net * net)735 static void __net_exit ipv6_frags_exit_net(struct net *net)
736 {
737 ip6_frags_ns_sysctl_unregister(net);
738 inet_frags_exit_net(&net->ipv6.frags, &ip6_frags);
739 }
740
741 static struct pernet_operations ip6_frags_ops = {
742 .init = ipv6_frags_init_net,
743 .exit = ipv6_frags_exit_net,
744 };
745
ipv6_frag_init(void)746 int __init ipv6_frag_init(void)
747 {
748 int ret;
749
750 ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT);
751 if (ret)
752 goto out;
753
754 ret = ip6_frags_sysctl_register();
755 if (ret)
756 goto err_sysctl;
757
758 ret = register_pernet_subsys(&ip6_frags_ops);
759 if (ret)
760 goto err_pernet;
761
762 ip6_frags.hashfn = ip6_hashfn;
763 ip6_frags.constructor = ip6_frag_init;
764 ip6_frags.destructor = NULL;
765 ip6_frags.skb_free = NULL;
766 ip6_frags.qsize = sizeof(struct frag_queue);
767 ip6_frags.match = ip6_frag_match;
768 ip6_frags.frag_expire = ip6_frag_expire;
769 ip6_frags.secret_interval = 10 * 60 * HZ;
770 inet_frags_init(&ip6_frags);
771 out:
772 return ret;
773
774 err_pernet:
775 ip6_frags_sysctl_unregister();
776 err_sysctl:
777 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
778 goto out;
779 }
780
ipv6_frag_exit(void)781 void ipv6_frag_exit(void)
782 {
783 inet_frags_fini(&ip6_frags);
784 ip6_frags_sysctl_unregister();
785 unregister_pernet_subsys(&ip6_frags_ops);
786 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
787 }
788