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
ip6_frag_nqueues(struct net * net)85 int ip6_frag_nqueues(struct net *net)
86 {
87 return net->ipv6.frags.nqueues;
88 }
89
ip6_frag_mem(struct net * net)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 */
inet6_hash_frag(__be32 id,const struct in6_addr * saddr,const struct in6_addr * daddr,u32 rnd)102 unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
103 const struct in6_addr *daddr, u32 rnd)
104 {
105 u32 a, b, c;
106
107 a = (__force u32)saddr->s6_addr32[0];
108 b = (__force u32)saddr->s6_addr32[1];
109 c = (__force u32)saddr->s6_addr32[2];
110
111 a += JHASH_GOLDEN_RATIO;
112 b += JHASH_GOLDEN_RATIO;
113 c += rnd;
114 __jhash_mix(a, b, c);
115
116 a += (__force u32)saddr->s6_addr32[3];
117 b += (__force u32)daddr->s6_addr32[0];
118 c += (__force u32)daddr->s6_addr32[1];
119 __jhash_mix(a, b, c);
120
121 a += (__force u32)daddr->s6_addr32[2];
122 b += (__force u32)daddr->s6_addr32[3];
123 c += (__force u32)id;
124 __jhash_mix(a, b, c);
125
126 return c & (INETFRAGS_HASHSZ - 1);
127 }
128 EXPORT_SYMBOL_GPL(inet6_hash_frag);
129
ip6_hashfn(struct inet_frag_queue * q)130 static unsigned int ip6_hashfn(struct inet_frag_queue *q)
131 {
132 struct frag_queue *fq;
133
134 fq = container_of(q, struct frag_queue, q);
135 return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr, ip6_frags.rnd);
136 }
137
ip6_frag_match(struct inet_frag_queue * q,void * a)138 int ip6_frag_match(struct inet_frag_queue *q, void *a)
139 {
140 struct frag_queue *fq;
141 struct ip6_create_arg *arg = a;
142
143 fq = container_of(q, struct frag_queue, q);
144 return (fq->id == arg->id &&
145 ipv6_addr_equal(&fq->saddr, arg->src) &&
146 ipv6_addr_equal(&fq->daddr, arg->dst));
147 }
148 EXPORT_SYMBOL(ip6_frag_match);
149
150 /* Memory Tracking Functions. */
frag_kfree_skb(struct netns_frags * nf,struct sk_buff * skb,int * work)151 static inline void frag_kfree_skb(struct netns_frags *nf,
152 struct sk_buff *skb, int *work)
153 {
154 if (work)
155 *work -= skb->truesize;
156 atomic_sub(skb->truesize, &nf->mem);
157 kfree_skb(skb);
158 }
159
ip6_frag_init(struct inet_frag_queue * q,void * a)160 void ip6_frag_init(struct inet_frag_queue *q, void *a)
161 {
162 struct frag_queue *fq = container_of(q, struct frag_queue, q);
163 struct ip6_create_arg *arg = a;
164
165 fq->id = arg->id;
166 ipv6_addr_copy(&fq->saddr, arg->src);
167 ipv6_addr_copy(&fq->daddr, arg->dst);
168 }
169 EXPORT_SYMBOL(ip6_frag_init);
170
171 /* Destruction primitives. */
172
fq_put(struct frag_queue * fq)173 static __inline__ void fq_put(struct frag_queue *fq)
174 {
175 inet_frag_put(&fq->q, &ip6_frags);
176 }
177
178 /* Kill fq entry. It is not destroyed immediately,
179 * because caller (and someone more) holds reference count.
180 */
fq_kill(struct frag_queue * fq)181 static __inline__ void fq_kill(struct frag_queue *fq)
182 {
183 inet_frag_kill(&fq->q, &ip6_frags);
184 }
185
ip6_evictor(struct net * net,struct inet6_dev * idev)186 static void ip6_evictor(struct net *net, struct inet6_dev *idev)
187 {
188 int evicted;
189
190 evicted = inet_frag_evictor(&net->ipv6.frags, &ip6_frags);
191 if (evicted)
192 IP6_ADD_STATS_BH(net, idev, IPSTATS_MIB_REASMFAILS, evicted);
193 }
194
ip6_frag_expire(unsigned long data)195 static void ip6_frag_expire(unsigned long data)
196 {
197 struct frag_queue *fq;
198 struct net_device *dev = NULL;
199 struct net *net;
200
201 fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
202
203 spin_lock(&fq->q.lock);
204
205 if (fq->q.last_in & INET_FRAG_COMPLETE)
206 goto out;
207
208 fq_kill(fq);
209
210 net = container_of(fq->q.net, struct net, ipv6.frags);
211 dev = dev_get_by_index(net, fq->iif);
212 if (!dev)
213 goto out;
214
215 rcu_read_lock();
216 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
217 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
218 rcu_read_unlock();
219
220 /* Don't send error if the first segment did not arrive. */
221 if (!(fq->q.last_in & INET_FRAG_FIRST_IN) || !fq->q.fragments)
222 goto out;
223
224 /*
225 But use as source device on which LAST ARRIVED
226 segment was received. And do not use fq->dev
227 pointer directly, device might already disappeared.
228 */
229 fq->q.fragments->dev = dev;
230 icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0, dev);
231 out:
232 if (dev)
233 dev_put(dev);
234 spin_unlock(&fq->q.lock);
235 fq_put(fq);
236 }
237
238 static __inline__ struct frag_queue *
fq_find(struct net * net,__be32 id,struct in6_addr * src,struct in6_addr * dst,struct inet6_dev * idev)239 fq_find(struct net *net, __be32 id, struct in6_addr *src, struct in6_addr *dst,
240 struct inet6_dev *idev)
241 {
242 struct inet_frag_queue *q;
243 struct ip6_create_arg arg;
244 unsigned int hash;
245
246 arg.id = id;
247 arg.src = src;
248 arg.dst = dst;
249
250 read_lock(&ip6_frags.lock);
251 hash = inet6_hash_frag(id, src, dst, ip6_frags.rnd);
252
253 q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash);
254 if (q == NULL)
255 goto oom;
256
257 return container_of(q, struct frag_queue, q);
258
259 oom:
260 IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_REASMFAILS);
261 return NULL;
262 }
263
ip6_frag_queue(struct frag_queue * fq,struct sk_buff * skb,struct frag_hdr * fhdr,int nhoff)264 static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
265 struct frag_hdr *fhdr, int nhoff)
266 {
267 struct sk_buff *prev, *next;
268 struct net_device *dev;
269 int offset, end;
270 struct net *net = dev_net(skb->dst->dev);
271
272 if (fq->q.last_in & INET_FRAG_COMPLETE)
273 goto err;
274
275 offset = ntohs(fhdr->frag_off) & ~0x7;
276 end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
277 ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
278
279 if ((unsigned int)end > IPV6_MAXPLEN) {
280 IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst),
281 IPSTATS_MIB_INHDRERRORS);
282 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
283 ((u8 *)&fhdr->frag_off -
284 skb_network_header(skb)));
285 return -1;
286 }
287
288 if (skb->ip_summed == CHECKSUM_COMPLETE) {
289 const unsigned char *nh = skb_network_header(skb);
290 skb->csum = csum_sub(skb->csum,
291 csum_partial(nh, (u8 *)(fhdr + 1) - nh,
292 0));
293 }
294
295 /* Is this the final fragment? */
296 if (!(fhdr->frag_off & htons(IP6_MF))) {
297 /* If we already have some bits beyond end
298 * or have different end, the segment is corrupted.
299 */
300 if (end < fq->q.len ||
301 ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len))
302 goto err;
303 fq->q.last_in |= INET_FRAG_LAST_IN;
304 fq->q.len = end;
305 } else {
306 /* Check if the fragment is rounded to 8 bytes.
307 * Required by the RFC.
308 */
309 if (end & 0x7) {
310 /* RFC2460 says always send parameter problem in
311 * this case. -DaveM
312 */
313 IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst),
314 IPSTATS_MIB_INHDRERRORS);
315 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
316 offsetof(struct ipv6hdr, payload_len));
317 return -1;
318 }
319 if (end > fq->q.len) {
320 /* Some bits beyond end -> corruption. */
321 if (fq->q.last_in & INET_FRAG_LAST_IN)
322 goto err;
323 fq->q.len = end;
324 }
325 }
326
327 if (end == offset)
328 goto err;
329
330 /* Point into the IP datagram 'data' part. */
331 if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
332 goto err;
333
334 if (pskb_trim_rcsum(skb, end - offset))
335 goto err;
336
337 /* Find out which fragments are in front and at the back of us
338 * in the chain of fragments so far. We must know where to put
339 * this fragment, right?
340 */
341 prev = NULL;
342 for(next = fq->q.fragments; next != NULL; next = next->next) {
343 if (FRAG6_CB(next)->offset >= offset)
344 break; /* bingo! */
345 prev = next;
346 }
347
348 /* We found where to put this one. Check for overlap with
349 * preceding fragment, and, if needed, align things so that
350 * any overlaps are eliminated.
351 */
352 if (prev) {
353 int i = (FRAG6_CB(prev)->offset + prev->len) - offset;
354
355 if (i > 0) {
356 offset += i;
357 if (end <= offset)
358 goto err;
359 if (!pskb_pull(skb, i))
360 goto err;
361 if (skb->ip_summed != CHECKSUM_UNNECESSARY)
362 skb->ip_summed = CHECKSUM_NONE;
363 }
364 }
365
366 /* Look for overlap with succeeding segments.
367 * If we can merge fragments, do it.
368 */
369 while (next && FRAG6_CB(next)->offset < end) {
370 int i = end - FRAG6_CB(next)->offset; /* overlap is 'i' bytes */
371
372 if (i < next->len) {
373 /* Eat head of the next overlapped fragment
374 * and leave the loop. The next ones cannot overlap.
375 */
376 if (!pskb_pull(next, i))
377 goto err;
378 FRAG6_CB(next)->offset += i; /* next fragment */
379 fq->q.meat -= i;
380 if (next->ip_summed != CHECKSUM_UNNECESSARY)
381 next->ip_summed = CHECKSUM_NONE;
382 break;
383 } else {
384 struct sk_buff *free_it = next;
385
386 /* Old fragment is completely overridden with
387 * new one drop it.
388 */
389 next = next->next;
390
391 if (prev)
392 prev->next = next;
393 else
394 fq->q.fragments = next;
395
396 fq->q.meat -= free_it->len;
397 frag_kfree_skb(fq->q.net, free_it, NULL);
398 }
399 }
400
401 FRAG6_CB(skb)->offset = offset;
402
403 /* Insert this fragment in the chain of fragments. */
404 skb->next = next;
405 if (prev)
406 prev->next = skb;
407 else
408 fq->q.fragments = skb;
409
410 dev = skb->dev;
411 if (dev) {
412 fq->iif = dev->ifindex;
413 skb->dev = NULL;
414 }
415 fq->q.stamp = skb->tstamp;
416 fq->q.meat += skb->len;
417 atomic_add(skb->truesize, &fq->q.net->mem);
418
419 /* The first fragment.
420 * nhoffset is obtained from the first fragment, of course.
421 */
422 if (offset == 0) {
423 fq->nhoffset = nhoff;
424 fq->q.last_in |= INET_FRAG_FIRST_IN;
425 }
426
427 if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
428 fq->q.meat == fq->q.len)
429 return ip6_frag_reasm(fq, prev, dev);
430
431 write_lock(&ip6_frags.lock);
432 list_move_tail(&fq->q.lru_list, &fq->q.net->lru_list);
433 write_unlock(&ip6_frags.lock);
434 return -1;
435
436 err:
437 IP6_INC_STATS(net, ip6_dst_idev(skb->dst),
438 IPSTATS_MIB_REASMFAILS);
439 kfree_skb(skb);
440 return -1;
441 }
442
443 /*
444 * Check if this packet is complete.
445 * Returns NULL on failure by any reason, and pointer
446 * to current nexthdr field in reassembled frame.
447 *
448 * It is called with locked fq, and caller must check that
449 * queue is eligible for reassembly i.e. it is not COMPLETE,
450 * the last and the first frames arrived and all the bits are here.
451 */
ip6_frag_reasm(struct frag_queue * fq,struct sk_buff * prev,struct net_device * dev)452 static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
453 struct net_device *dev)
454 {
455 struct net *net = container_of(fq->q.net, struct net, ipv6.frags);
456 struct sk_buff *fp, *head = fq->q.fragments;
457 int payload_len;
458 unsigned int nhoff;
459
460 fq_kill(fq);
461
462 /* Make the one we just received the head. */
463 if (prev) {
464 head = prev->next;
465 fp = skb_clone(head, GFP_ATOMIC);
466
467 if (!fp)
468 goto out_oom;
469
470 fp->next = head->next;
471 prev->next = fp;
472
473 skb_morph(head, fq->q.fragments);
474 head->next = fq->q.fragments->next;
475
476 kfree_skb(fq->q.fragments);
477 fq->q.fragments = head;
478 }
479
480 WARN_ON(head == NULL);
481 WARN_ON(FRAG6_CB(head)->offset != 0);
482
483 /* Unfragmented part is taken from the first segment. */
484 payload_len = ((head->data - skb_network_header(head)) -
485 sizeof(struct ipv6hdr) + fq->q.len -
486 sizeof(struct frag_hdr));
487 if (payload_len > IPV6_MAXPLEN)
488 goto out_oversize;
489
490 /* Head of list must not be cloned. */
491 if (skb_cloned(head) && pskb_expand_head(head, 0, 0, GFP_ATOMIC))
492 goto out_oom;
493
494 /* If the first fragment is fragmented itself, we split
495 * it to two chunks: the first with data and paged part
496 * and the second, holding only fragments. */
497 if (skb_shinfo(head)->frag_list) {
498 struct sk_buff *clone;
499 int i, plen = 0;
500
501 if ((clone = alloc_skb(0, GFP_ATOMIC)) == NULL)
502 goto out_oom;
503 clone->next = head->next;
504 head->next = clone;
505 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
506 skb_shinfo(head)->frag_list = NULL;
507 for (i=0; i<skb_shinfo(head)->nr_frags; i++)
508 plen += skb_shinfo(head)->frags[i].size;
509 clone->len = clone->data_len = head->data_len - plen;
510 head->data_len -= clone->len;
511 head->len -= clone->len;
512 clone->csum = 0;
513 clone->ip_summed = head->ip_summed;
514 atomic_add(clone->truesize, &fq->q.net->mem);
515 }
516
517 /* We have to remove fragment header from datagram and to relocate
518 * header in order to calculate ICV correctly. */
519 nhoff = fq->nhoffset;
520 skb_network_header(head)[nhoff] = skb_transport_header(head)[0];
521 memmove(head->head + sizeof(struct frag_hdr), head->head,
522 (head->data - head->head) - sizeof(struct frag_hdr));
523 head->mac_header += sizeof(struct frag_hdr);
524 head->network_header += sizeof(struct frag_hdr);
525
526 skb_shinfo(head)->frag_list = head->next;
527 skb_reset_transport_header(head);
528 skb_push(head, head->data - skb_network_header(head));
529 atomic_sub(head->truesize, &fq->q.net->mem);
530
531 for (fp=head->next; fp; fp = fp->next) {
532 head->data_len += fp->len;
533 head->len += fp->len;
534 if (head->ip_summed != fp->ip_summed)
535 head->ip_summed = CHECKSUM_NONE;
536 else if (head->ip_summed == CHECKSUM_COMPLETE)
537 head->csum = csum_add(head->csum, fp->csum);
538 head->truesize += fp->truesize;
539 atomic_sub(fp->truesize, &fq->q.net->mem);
540 }
541
542 head->next = NULL;
543 head->dev = dev;
544 head->tstamp = fq->q.stamp;
545 ipv6_hdr(head)->payload_len = htons(payload_len);
546 IP6CB(head)->nhoff = nhoff;
547
548 /* Yes, and fold redundant checksum back. 8) */
549 if (head->ip_summed == CHECKSUM_COMPLETE)
550 head->csum = csum_partial(skb_network_header(head),
551 skb_network_header_len(head),
552 head->csum);
553
554 rcu_read_lock();
555 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
556 rcu_read_unlock();
557 fq->q.fragments = NULL;
558 return 1;
559
560 out_oversize:
561 if (net_ratelimit())
562 printk(KERN_DEBUG "ip6_frag_reasm: payload len = %d\n", payload_len);
563 goto out_fail;
564 out_oom:
565 if (net_ratelimit())
566 printk(KERN_DEBUG "ip6_frag_reasm: no memory for reassembly\n");
567 out_fail:
568 rcu_read_lock();
569 IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
570 rcu_read_unlock();
571 return -1;
572 }
573
ipv6_frag_rcv(struct sk_buff * skb)574 static int ipv6_frag_rcv(struct sk_buff *skb)
575 {
576 struct frag_hdr *fhdr;
577 struct frag_queue *fq;
578 struct ipv6hdr *hdr = ipv6_hdr(skb);
579 struct net *net = dev_net(skb->dst->dev);
580
581 IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMREQDS);
582
583 /* Jumbo payload inhibits frag. header */
584 if (hdr->payload_len==0)
585 goto fail_hdr;
586
587 if (!pskb_may_pull(skb, (skb_transport_offset(skb) +
588 sizeof(struct frag_hdr))))
589 goto fail_hdr;
590
591 hdr = ipv6_hdr(skb);
592 fhdr = (struct frag_hdr *)skb_transport_header(skb);
593
594 if (!(fhdr->frag_off & htons(0xFFF9))) {
595 /* It is not a fragmented frame */
596 skb->transport_header += sizeof(struct frag_hdr);
597 IP6_INC_STATS_BH(net,
598 ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMOKS);
599
600 IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb);
601 return 1;
602 }
603
604 if (atomic_read(&net->ipv6.frags.mem) > net->ipv6.frags.high_thresh)
605 ip6_evictor(net, ip6_dst_idev(skb->dst));
606
607 if ((fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr,
608 ip6_dst_idev(skb->dst))) != NULL) {
609 int ret;
610
611 spin_lock(&fq->q.lock);
612
613 ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
614
615 spin_unlock(&fq->q.lock);
616 fq_put(fq);
617 return ret;
618 }
619
620 IP6_INC_STATS_BH(net, ip6_dst_idev(skb->dst), IPSTATS_MIB_REASMFAILS);
621 kfree_skb(skb);
622 return -1;
623
624 fail_hdr:
625 IP6_INC_STATS(net, ip6_dst_idev(skb->dst), IPSTATS_MIB_INHDRERRORS);
626 icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb));
627 return -1;
628 }
629
630 static struct inet6_protocol frag_protocol =
631 {
632 .handler = ipv6_frag_rcv,
633 .flags = INET6_PROTO_NOPOLICY,
634 };
635
636 #ifdef CONFIG_SYSCTL
637 static struct ctl_table ip6_frags_ns_ctl_table[] = {
638 {
639 .ctl_name = NET_IPV6_IP6FRAG_HIGH_THRESH,
640 .procname = "ip6frag_high_thresh",
641 .data = &init_net.ipv6.frags.high_thresh,
642 .maxlen = sizeof(int),
643 .mode = 0644,
644 .proc_handler = proc_dointvec
645 },
646 {
647 .ctl_name = NET_IPV6_IP6FRAG_LOW_THRESH,
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 .ctl_name = NET_IPV6_IP6FRAG_TIME,
656 .procname = "ip6frag_time",
657 .data = &init_net.ipv6.frags.timeout,
658 .maxlen = sizeof(int),
659 .mode = 0644,
660 .proc_handler = proc_dointvec_jiffies,
661 .strategy = sysctl_jiffies,
662 },
663 { }
664 };
665
666 static struct ctl_table ip6_frags_ctl_table[] = {
667 {
668 .ctl_name = NET_IPV6_IP6FRAG_SECRET_INTERVAL,
669 .procname = "ip6frag_secret_interval",
670 .data = &ip6_frags.secret_interval,
671 .maxlen = sizeof(int),
672 .mode = 0644,
673 .proc_handler = proc_dointvec_jiffies,
674 .strategy = sysctl_jiffies
675 },
676 { }
677 };
678
ip6_frags_ns_sysctl_register(struct net * net)679 static int ip6_frags_ns_sysctl_register(struct net *net)
680 {
681 struct ctl_table *table;
682 struct ctl_table_header *hdr;
683
684 table = ip6_frags_ns_ctl_table;
685 if (net != &init_net) {
686 table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL);
687 if (table == NULL)
688 goto err_alloc;
689
690 table[0].data = &net->ipv6.frags.high_thresh;
691 table[1].data = &net->ipv6.frags.low_thresh;
692 table[2].data = &net->ipv6.frags.timeout;
693 }
694
695 hdr = register_net_sysctl_table(net, net_ipv6_ctl_path, table);
696 if (hdr == NULL)
697 goto err_reg;
698
699 net->ipv6.sysctl.frags_hdr = hdr;
700 return 0;
701
702 err_reg:
703 if (net != &init_net)
704 kfree(table);
705 err_alloc:
706 return -ENOMEM;
707 }
708
ip6_frags_ns_sysctl_unregister(struct net * net)709 static void ip6_frags_ns_sysctl_unregister(struct net *net)
710 {
711 struct ctl_table *table;
712
713 table = net->ipv6.sysctl.frags_hdr->ctl_table_arg;
714 unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr);
715 kfree(table);
716 }
717
718 static struct ctl_table_header *ip6_ctl_header;
719
ip6_frags_sysctl_register(void)720 static int ip6_frags_sysctl_register(void)
721 {
722 ip6_ctl_header = register_net_sysctl_rotable(net_ipv6_ctl_path,
723 ip6_frags_ctl_table);
724 return ip6_ctl_header == NULL ? -ENOMEM : 0;
725 }
726
ip6_frags_sysctl_unregister(void)727 static void ip6_frags_sysctl_unregister(void)
728 {
729 unregister_net_sysctl_table(ip6_ctl_header);
730 }
731 #else
ip6_frags_ns_sysctl_register(struct net * net)732 static inline int ip6_frags_ns_sysctl_register(struct net *net)
733 {
734 return 0;
735 }
736
ip6_frags_ns_sysctl_unregister(struct net * net)737 static inline void ip6_frags_ns_sysctl_unregister(struct net *net)
738 {
739 }
740
ip6_frags_sysctl_register(void)741 static inline int ip6_frags_sysctl_register(void)
742 {
743 return 0;
744 }
745
ip6_frags_sysctl_unregister(void)746 static inline void ip6_frags_sysctl_unregister(void)
747 {
748 }
749 #endif
750
ipv6_frags_init_net(struct net * net)751 static int ipv6_frags_init_net(struct net *net)
752 {
753 net->ipv6.frags.high_thresh = 256 * 1024;
754 net->ipv6.frags.low_thresh = 192 * 1024;
755 net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT;
756
757 inet_frags_init_net(&net->ipv6.frags);
758
759 return ip6_frags_ns_sysctl_register(net);
760 }
761
ipv6_frags_exit_net(struct net * net)762 static void ipv6_frags_exit_net(struct net *net)
763 {
764 ip6_frags_ns_sysctl_unregister(net);
765 inet_frags_exit_net(&net->ipv6.frags, &ip6_frags);
766 }
767
768 static struct pernet_operations ip6_frags_ops = {
769 .init = ipv6_frags_init_net,
770 .exit = ipv6_frags_exit_net,
771 };
772
ipv6_frag_init(void)773 int __init ipv6_frag_init(void)
774 {
775 int ret;
776
777 ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT);
778 if (ret)
779 goto out;
780
781 ret = ip6_frags_sysctl_register();
782 if (ret)
783 goto err_sysctl;
784
785 ret = register_pernet_subsys(&ip6_frags_ops);
786 if (ret)
787 goto err_pernet;
788
789 ip6_frags.hashfn = ip6_hashfn;
790 ip6_frags.constructor = ip6_frag_init;
791 ip6_frags.destructor = NULL;
792 ip6_frags.skb_free = NULL;
793 ip6_frags.qsize = sizeof(struct frag_queue);
794 ip6_frags.match = ip6_frag_match;
795 ip6_frags.frag_expire = ip6_frag_expire;
796 ip6_frags.secret_interval = 10 * 60 * HZ;
797 inet_frags_init(&ip6_frags);
798 out:
799 return ret;
800
801 err_pernet:
802 ip6_frags_sysctl_unregister();
803 err_sysctl:
804 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
805 goto out;
806 }
807
ipv6_frag_exit(void)808 void ipv6_frag_exit(void)
809 {
810 inet_frags_fini(&ip6_frags);
811 ip6_frags_sysctl_unregister();
812 unregister_pernet_subsys(&ip6_frags_ops);
813 inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
814 }
815