1 /*
2 * IPv6 fragment reassembly for connection tracking
3 *
4 * Copyright (C)2004 USAGI/WIDE Project
5 *
6 * Author:
7 * Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
8 *
9 * Based on: net/ipv6/reassembly.c
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
15 */
16
17 #define pr_fmt(fmt) "IPv6-nf: " fmt
18
19 #include <linux/errno.h>
20 #include <linux/types.h>
21 #include <linux/string.h>
22 #include <linux/socket.h>
23 #include <linux/sockios.h>
24 #include <linux/jiffies.h>
25 #include <linux/net.h>
26 #include <linux/list.h>
27 #include <linux/netdevice.h>
28 #include <linux/in6.h>
29 #include <linux/ipv6.h>
30 #include <linux/icmpv6.h>
31 #include <linux/random.h>
32 #include <linux/slab.h>
33
34 #include <net/sock.h>
35 #include <net/snmp.h>
36 #include <net/inet_frag.h>
37
38 #include <net/ipv6.h>
39 #include <net/protocol.h>
40 #include <net/transp_v6.h>
41 #include <net/rawv6.h>
42 #include <net/ndisc.h>
43 #include <net/addrconf.h>
44 #include <net/inet_ecn.h>
45 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
46 #include <linux/sysctl.h>
47 #include <linux/netfilter.h>
48 #include <linux/netfilter_ipv6.h>
49 #include <linux/kernel.h>
50 #include <linux/module.h>
51 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
52
53 static const char nf_frags_cache_name[] = "nf-frags";
54
55 struct nf_ct_frag6_skb_cb
56 {
57 struct inet6_skb_parm h;
58 int offset;
59 struct sk_buff *orig;
60 };
61
62 #define NFCT_FRAG6_CB(skb) ((struct nf_ct_frag6_skb_cb*)((skb)->cb))
63
64 static struct inet_frags nf_frags;
65
66 #ifdef CONFIG_SYSCTL
67 static int zero;
68
69 static struct ctl_table nf_ct_frag6_sysctl_table[] = {
70 {
71 .procname = "nf_conntrack_frag6_timeout",
72 .data = &init_net.nf_frag.frags.timeout,
73 .maxlen = sizeof(unsigned int),
74 .mode = 0644,
75 .proc_handler = proc_dointvec_jiffies,
76 },
77 {
78 .procname = "nf_conntrack_frag6_low_thresh",
79 .data = &init_net.nf_frag.frags.low_thresh,
80 .maxlen = sizeof(unsigned int),
81 .mode = 0644,
82 .proc_handler = proc_dointvec_minmax,
83 .extra1 = &zero,
84 .extra2 = &init_net.nf_frag.frags.high_thresh
85 },
86 {
87 .procname = "nf_conntrack_frag6_high_thresh",
88 .data = &init_net.nf_frag.frags.high_thresh,
89 .maxlen = sizeof(unsigned int),
90 .mode = 0644,
91 .proc_handler = proc_dointvec_minmax,
92 .extra1 = &init_net.nf_frag.frags.low_thresh
93 },
94 { }
95 };
96
nf_ct_frag6_sysctl_register(struct net * net)97 static int nf_ct_frag6_sysctl_register(struct net *net)
98 {
99 struct ctl_table *table;
100 struct ctl_table_header *hdr;
101
102 table = nf_ct_frag6_sysctl_table;
103 if (!net_eq(net, &init_net)) {
104 table = kmemdup(table, sizeof(nf_ct_frag6_sysctl_table),
105 GFP_KERNEL);
106 if (table == NULL)
107 goto err_alloc;
108
109 table[0].data = &net->nf_frag.frags.timeout;
110 table[1].data = &net->nf_frag.frags.low_thresh;
111 table[1].extra2 = &net->nf_frag.frags.high_thresh;
112 table[2].data = &net->nf_frag.frags.high_thresh;
113 table[2].extra1 = &net->nf_frag.frags.low_thresh;
114 table[2].extra2 = &init_net.nf_frag.frags.high_thresh;
115 }
116
117 hdr = register_net_sysctl(net, "net/netfilter", table);
118 if (hdr == NULL)
119 goto err_reg;
120
121 net->nf_frag.sysctl.frags_hdr = hdr;
122 return 0;
123
124 err_reg:
125 if (!net_eq(net, &init_net))
126 kfree(table);
127 err_alloc:
128 return -ENOMEM;
129 }
130
nf_ct_frags6_sysctl_unregister(struct net * net)131 static void __net_exit nf_ct_frags6_sysctl_unregister(struct net *net)
132 {
133 struct ctl_table *table;
134
135 table = net->nf_frag.sysctl.frags_hdr->ctl_table_arg;
136 unregister_net_sysctl_table(net->nf_frag.sysctl.frags_hdr);
137 if (!net_eq(net, &init_net))
138 kfree(table);
139 }
140
141 #else
nf_ct_frag6_sysctl_register(struct net * net)142 static int nf_ct_frag6_sysctl_register(struct net *net)
143 {
144 return 0;
145 }
nf_ct_frags6_sysctl_unregister(struct net * net)146 static void __net_exit nf_ct_frags6_sysctl_unregister(struct net *net)
147 {
148 }
149 #endif
150
ip6_frag_ecn(const struct ipv6hdr * ipv6h)151 static inline u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h)
152 {
153 return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK);
154 }
155
nf_hash_frag(__be32 id,const struct in6_addr * saddr,const struct in6_addr * daddr)156 static unsigned int nf_hash_frag(__be32 id, const struct in6_addr *saddr,
157 const struct in6_addr *daddr)
158 {
159 net_get_random_once(&nf_frags.rnd, sizeof(nf_frags.rnd));
160 return jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr),
161 (__force u32)id, nf_frags.rnd);
162 }
163
164
nf_hashfn(const struct inet_frag_queue * q)165 static unsigned int nf_hashfn(const struct inet_frag_queue *q)
166 {
167 const struct frag_queue *nq;
168
169 nq = container_of(q, struct frag_queue, q);
170 return nf_hash_frag(nq->id, &nq->saddr, &nq->daddr);
171 }
172
nf_skb_free(struct sk_buff * skb)173 static void nf_skb_free(struct sk_buff *skb)
174 {
175 if (NFCT_FRAG6_CB(skb)->orig)
176 kfree_skb(NFCT_FRAG6_CB(skb)->orig);
177 }
178
nf_ct_frag6_expire(unsigned long data)179 static void nf_ct_frag6_expire(unsigned long data)
180 {
181 struct frag_queue *fq;
182 struct net *net;
183
184 fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
185 net = container_of(fq->q.net, struct net, nf_frag.frags);
186
187 ip6_expire_frag_queue(net, fq, &nf_frags);
188 }
189
190 /* Creation primitives. */
fq_find(struct net * net,__be32 id,u32 user,struct in6_addr * src,struct in6_addr * dst,int iif,u8 ecn)191 static inline struct frag_queue *fq_find(struct net *net, __be32 id,
192 u32 user, struct in6_addr *src,
193 struct in6_addr *dst, int iif, u8 ecn)
194 {
195 struct inet_frag_queue *q;
196 struct ip6_create_arg arg;
197 unsigned int hash;
198
199 arg.id = id;
200 arg.user = user;
201 arg.src = src;
202 arg.dst = dst;
203 arg.iif = iif;
204 arg.ecn = ecn;
205
206 local_bh_disable();
207 hash = nf_hash_frag(id, src, dst);
208
209 q = inet_frag_find(&net->nf_frag.frags, &nf_frags, &arg, hash);
210 local_bh_enable();
211 if (IS_ERR_OR_NULL(q)) {
212 inet_frag_maybe_warn_overflow(q, pr_fmt());
213 return NULL;
214 }
215 return container_of(q, struct frag_queue, q);
216 }
217
218
nf_ct_frag6_queue(struct frag_queue * fq,struct sk_buff * skb,const struct frag_hdr * fhdr,int nhoff)219 static int nf_ct_frag6_queue(struct frag_queue *fq, struct sk_buff *skb,
220 const struct frag_hdr *fhdr, int nhoff)
221 {
222 struct sk_buff *prev, *next;
223 unsigned int payload_len;
224 int offset, end;
225 u8 ecn;
226
227 if (fq->q.flags & INET_FRAG_COMPLETE) {
228 pr_debug("Already completed\n");
229 goto err;
230 }
231
232 payload_len = ntohs(ipv6_hdr(skb)->payload_len);
233
234 offset = ntohs(fhdr->frag_off) & ~0x7;
235 end = offset + (payload_len -
236 ((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
237
238 if ((unsigned int)end > IPV6_MAXPLEN) {
239 pr_debug("offset is too large.\n");
240 return -1;
241 }
242
243 ecn = ip6_frag_ecn(ipv6_hdr(skb));
244
245 if (skb->ip_summed == CHECKSUM_COMPLETE) {
246 const unsigned char *nh = skb_network_header(skb);
247 skb->csum = csum_sub(skb->csum,
248 csum_partial(nh, (u8 *)(fhdr + 1) - nh,
249 0));
250 }
251
252 /* Is this the final fragment? */
253 if (!(fhdr->frag_off & htons(IP6_MF))) {
254 /* If we already have some bits beyond end
255 * or have different end, the segment is corrupted.
256 */
257 if (end < fq->q.len ||
258 ((fq->q.flags & INET_FRAG_LAST_IN) && end != fq->q.len)) {
259 pr_debug("already received last fragment\n");
260 goto err;
261 }
262 fq->q.flags |= INET_FRAG_LAST_IN;
263 fq->q.len = end;
264 } else {
265 /* Check if the fragment is rounded to 8 bytes.
266 * Required by the RFC.
267 */
268 if (end & 0x7) {
269 /* RFC2460 says always send parameter problem in
270 * this case. -DaveM
271 */
272 pr_debug("end of fragment not rounded to 8 bytes.\n");
273 return -1;
274 }
275 if (end > fq->q.len) {
276 /* Some bits beyond end -> corruption. */
277 if (fq->q.flags & INET_FRAG_LAST_IN) {
278 pr_debug("last packet already reached.\n");
279 goto err;
280 }
281 fq->q.len = end;
282 }
283 }
284
285 if (end == offset)
286 goto err;
287
288 /* Point into the IP datagram 'data' part. */
289 if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data)) {
290 pr_debug("queue: message is too short.\n");
291 goto err;
292 }
293 if (pskb_trim_rcsum(skb, end - offset)) {
294 pr_debug("Can't trim\n");
295 goto err;
296 }
297
298 /* Find out which fragments are in front and at the back of us
299 * in the chain of fragments so far. We must know where to put
300 * this fragment, right?
301 */
302 prev = fq->q.fragments_tail;
303 if (!prev || NFCT_FRAG6_CB(prev)->offset < offset) {
304 next = NULL;
305 goto found;
306 }
307 prev = NULL;
308 for (next = fq->q.fragments; next != NULL; next = next->next) {
309 if (NFCT_FRAG6_CB(next)->offset >= offset)
310 break; /* bingo! */
311 prev = next;
312 }
313
314 found:
315 /* RFC5722, Section 4:
316 * When reassembling an IPv6 datagram, if
317 * one or more its constituent fragments is determined to be an
318 * overlapping fragment, the entire datagram (and any constituent
319 * fragments, including those not yet received) MUST be silently
320 * discarded.
321 */
322
323 /* Check for overlap with preceding fragment. */
324 if (prev &&
325 (NFCT_FRAG6_CB(prev)->offset + prev->len) > offset)
326 goto discard_fq;
327
328 /* Look for overlap with succeeding segment. */
329 if (next && NFCT_FRAG6_CB(next)->offset < end)
330 goto discard_fq;
331
332 NFCT_FRAG6_CB(skb)->offset = offset;
333
334 /* Insert this fragment in the chain of fragments. */
335 skb->next = next;
336 if (!next)
337 fq->q.fragments_tail = skb;
338 if (prev)
339 prev->next = skb;
340 else
341 fq->q.fragments = skb;
342
343 if (skb->dev) {
344 fq->iif = skb->dev->ifindex;
345 skb->dev = NULL;
346 }
347 fq->q.stamp = skb->tstamp;
348 fq->q.meat += skb->len;
349 fq->ecn |= ecn;
350 if (payload_len > fq->q.max_size)
351 fq->q.max_size = payload_len;
352 add_frag_mem_limit(&fq->q, skb->truesize);
353
354 /* The first fragment.
355 * nhoffset is obtained from the first fragment, of course.
356 */
357 if (offset == 0) {
358 fq->nhoffset = nhoff;
359 fq->q.flags |= INET_FRAG_FIRST_IN;
360 }
361
362 return 0;
363
364 discard_fq:
365 inet_frag_kill(&fq->q, &nf_frags);
366 err:
367 return -1;
368 }
369
370 /*
371 * Check if this packet is complete.
372 * Returns NULL on failure by any reason, and pointer
373 * to current nexthdr field in reassembled frame.
374 *
375 * It is called with locked fq, and caller must check that
376 * queue is eligible for reassembly i.e. it is not COMPLETE,
377 * the last and the first frames arrived and all the bits are here.
378 */
379 static struct sk_buff *
nf_ct_frag6_reasm(struct frag_queue * fq,struct net_device * dev)380 nf_ct_frag6_reasm(struct frag_queue *fq, struct net_device *dev)
381 {
382 struct sk_buff *fp, *op, *head = fq->q.fragments;
383 int payload_len;
384 u8 ecn;
385
386 inet_frag_kill(&fq->q, &nf_frags);
387
388 WARN_ON(head == NULL);
389 WARN_ON(NFCT_FRAG6_CB(head)->offset != 0);
390
391 ecn = ip_frag_ecn_table[fq->ecn];
392 if (unlikely(ecn == 0xff))
393 goto out_fail;
394
395 /* Unfragmented part is taken from the first segment. */
396 payload_len = ((head->data - skb_network_header(head)) -
397 sizeof(struct ipv6hdr) + fq->q.len -
398 sizeof(struct frag_hdr));
399 if (payload_len > IPV6_MAXPLEN) {
400 pr_debug("payload len is too large.\n");
401 goto out_oversize;
402 }
403
404 /* Head of list must not be cloned. */
405 if (skb_unclone(head, GFP_ATOMIC)) {
406 pr_debug("skb is cloned but can't expand head");
407 goto out_oom;
408 }
409
410 /* If the first fragment is fragmented itself, we split
411 * it to two chunks: the first with data and paged part
412 * and the second, holding only fragments. */
413 if (skb_has_frag_list(head)) {
414 struct sk_buff *clone;
415 int i, plen = 0;
416
417 clone = alloc_skb(0, GFP_ATOMIC);
418 if (clone == NULL)
419 goto out_oom;
420
421 clone->next = head->next;
422 head->next = clone;
423 skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
424 skb_frag_list_init(head);
425 for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
426 plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
427 clone->len = clone->data_len = head->data_len - plen;
428 head->data_len -= clone->len;
429 head->len -= clone->len;
430 clone->csum = 0;
431 clone->ip_summed = head->ip_summed;
432
433 NFCT_FRAG6_CB(clone)->orig = NULL;
434 add_frag_mem_limit(&fq->q, clone->truesize);
435 }
436
437 /* We have to remove fragment header from datagram and to relocate
438 * header in order to calculate ICV correctly. */
439 skb_network_header(head)[fq->nhoffset] = skb_transport_header(head)[0];
440 memmove(head->head + sizeof(struct frag_hdr), head->head,
441 (head->data - head->head) - sizeof(struct frag_hdr));
442 head->mac_header += sizeof(struct frag_hdr);
443 head->network_header += sizeof(struct frag_hdr);
444
445 skb_shinfo(head)->frag_list = head->next;
446 skb_reset_transport_header(head);
447 skb_push(head, head->data - skb_network_header(head));
448
449 for (fp=head->next; fp; fp = fp->next) {
450 head->data_len += fp->len;
451 head->len += fp->len;
452 if (head->ip_summed != fp->ip_summed)
453 head->ip_summed = CHECKSUM_NONE;
454 else if (head->ip_summed == CHECKSUM_COMPLETE)
455 head->csum = csum_add(head->csum, fp->csum);
456 head->truesize += fp->truesize;
457 }
458 sub_frag_mem_limit(&fq->q, head->truesize);
459
460 head->ignore_df = 1;
461 head->next = NULL;
462 head->dev = dev;
463 head->tstamp = fq->q.stamp;
464 ipv6_hdr(head)->payload_len = htons(payload_len);
465 ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn);
466 IP6CB(head)->frag_max_size = sizeof(struct ipv6hdr) + fq->q.max_size;
467
468 /* Yes, and fold redundant checksum back. 8) */
469 if (head->ip_summed == CHECKSUM_COMPLETE)
470 head->csum = csum_partial(skb_network_header(head),
471 skb_network_header_len(head),
472 head->csum);
473
474 fq->q.fragments = NULL;
475 fq->q.fragments_tail = NULL;
476
477 /* all original skbs are linked into the NFCT_FRAG6_CB(head).orig */
478 fp = skb_shinfo(head)->frag_list;
479 if (fp && NFCT_FRAG6_CB(fp)->orig == NULL)
480 /* at above code, head skb is divided into two skbs. */
481 fp = fp->next;
482
483 op = NFCT_FRAG6_CB(head)->orig;
484 for (; fp; fp = fp->next) {
485 struct sk_buff *orig = NFCT_FRAG6_CB(fp)->orig;
486
487 op->next = orig;
488 op = orig;
489 NFCT_FRAG6_CB(fp)->orig = NULL;
490 }
491
492 return head;
493
494 out_oversize:
495 net_dbg_ratelimited("nf_ct_frag6_reasm: payload len = %d\n",
496 payload_len);
497 goto out_fail;
498 out_oom:
499 net_dbg_ratelimited("nf_ct_frag6_reasm: no memory for reassembly\n");
500 out_fail:
501 return NULL;
502 }
503
504 /*
505 * find the header just before Fragment Header.
506 *
507 * if success return 0 and set ...
508 * (*prevhdrp): the value of "Next Header Field" in the header
509 * just before Fragment Header.
510 * (*prevhoff): the offset of "Next Header Field" in the header
511 * just before Fragment Header.
512 * (*fhoff) : the offset of Fragment Header.
513 *
514 * Based on ipv6_skip_hdr() in net/ipv6/exthdr.c
515 *
516 */
517 static int
find_prev_fhdr(struct sk_buff * skb,u8 * prevhdrp,int * prevhoff,int * fhoff)518 find_prev_fhdr(struct sk_buff *skb, u8 *prevhdrp, int *prevhoff, int *fhoff)
519 {
520 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
521 const int netoff = skb_network_offset(skb);
522 u8 prev_nhoff = netoff + offsetof(struct ipv6hdr, nexthdr);
523 int start = netoff + sizeof(struct ipv6hdr);
524 int len = skb->len - start;
525 u8 prevhdr = NEXTHDR_IPV6;
526
527 while (nexthdr != NEXTHDR_FRAGMENT) {
528 struct ipv6_opt_hdr hdr;
529 int hdrlen;
530
531 if (!ipv6_ext_hdr(nexthdr)) {
532 return -1;
533 }
534 if (nexthdr == NEXTHDR_NONE) {
535 pr_debug("next header is none\n");
536 return -1;
537 }
538 if (len < (int)sizeof(struct ipv6_opt_hdr)) {
539 pr_debug("too short\n");
540 return -1;
541 }
542 if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
543 BUG();
544 if (nexthdr == NEXTHDR_AUTH)
545 hdrlen = (hdr.hdrlen+2)<<2;
546 else
547 hdrlen = ipv6_optlen(&hdr);
548
549 prevhdr = nexthdr;
550 prev_nhoff = start;
551
552 nexthdr = hdr.nexthdr;
553 len -= hdrlen;
554 start += hdrlen;
555 }
556
557 if (len < 0)
558 return -1;
559
560 *prevhdrp = prevhdr;
561 *prevhoff = prev_nhoff;
562 *fhoff = start;
563
564 return 0;
565 }
566
nf_ct_frag6_gather(struct sk_buff * skb,u32 user)567 struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb, u32 user)
568 {
569 struct sk_buff *clone;
570 struct net_device *dev = skb->dev;
571 struct net *net = skb_dst(skb) ? dev_net(skb_dst(skb)->dev)
572 : dev_net(skb->dev);
573 struct frag_hdr *fhdr;
574 struct frag_queue *fq;
575 struct ipv6hdr *hdr;
576 int fhoff, nhoff;
577 u8 prevhdr;
578 struct sk_buff *ret_skb = NULL;
579
580 /* Jumbo payload inhibits frag. header */
581 if (ipv6_hdr(skb)->payload_len == 0) {
582 pr_debug("payload len = 0\n");
583 return skb;
584 }
585
586 if (find_prev_fhdr(skb, &prevhdr, &nhoff, &fhoff) < 0)
587 return skb;
588
589 clone = skb_clone(skb, GFP_ATOMIC);
590 if (clone == NULL) {
591 pr_debug("Can't clone skb\n");
592 return skb;
593 }
594
595 NFCT_FRAG6_CB(clone)->orig = skb;
596
597 if (!pskb_may_pull(clone, fhoff + sizeof(*fhdr))) {
598 pr_debug("message is too short.\n");
599 goto ret_orig;
600 }
601
602 skb_set_transport_header(clone, fhoff);
603 hdr = ipv6_hdr(clone);
604 fhdr = (struct frag_hdr *)skb_transport_header(clone);
605
606 fq = fq_find(net, fhdr->identification, user, &hdr->saddr, &hdr->daddr,
607 skb->dev ? skb->dev->ifindex : 0, ip6_frag_ecn(hdr));
608 if (fq == NULL) {
609 pr_debug("Can't find and can't create new queue\n");
610 goto ret_orig;
611 }
612
613 spin_lock_bh(&fq->q.lock);
614
615 if (nf_ct_frag6_queue(fq, clone, fhdr, nhoff) < 0) {
616 spin_unlock_bh(&fq->q.lock);
617 pr_debug("Can't insert skb to queue\n");
618 inet_frag_put(&fq->q, &nf_frags);
619 goto ret_orig;
620 }
621
622 if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
623 fq->q.meat == fq->q.len) {
624 ret_skb = nf_ct_frag6_reasm(fq, dev);
625 if (ret_skb == NULL)
626 pr_debug("Can't reassemble fragmented packets\n");
627 }
628 spin_unlock_bh(&fq->q.lock);
629
630 inet_frag_put(&fq->q, &nf_frags);
631 return ret_skb;
632
633 ret_orig:
634 kfree_skb(clone);
635 return skb;
636 }
637
nf_ct_frag6_consume_orig(struct sk_buff * skb)638 void nf_ct_frag6_consume_orig(struct sk_buff *skb)
639 {
640 struct sk_buff *s, *s2;
641
642 for (s = NFCT_FRAG6_CB(skb)->orig; s;) {
643 s2 = s->next;
644 s->next = NULL;
645 consume_skb(s);
646 s = s2;
647 }
648 }
649
nf_ct_net_init(struct net * net)650 static int nf_ct_net_init(struct net *net)
651 {
652 net->nf_frag.frags.high_thresh = IPV6_FRAG_HIGH_THRESH;
653 net->nf_frag.frags.low_thresh = IPV6_FRAG_LOW_THRESH;
654 net->nf_frag.frags.timeout = IPV6_FRAG_TIMEOUT;
655 inet_frags_init_net(&net->nf_frag.frags);
656
657 return nf_ct_frag6_sysctl_register(net);
658 }
659
nf_ct_net_exit(struct net * net)660 static void nf_ct_net_exit(struct net *net)
661 {
662 nf_ct_frags6_sysctl_unregister(net);
663 inet_frags_exit_net(&net->nf_frag.frags, &nf_frags);
664 }
665
666 static struct pernet_operations nf_ct_net_ops = {
667 .init = nf_ct_net_init,
668 .exit = nf_ct_net_exit,
669 };
670
nf_ct_frag6_init(void)671 int nf_ct_frag6_init(void)
672 {
673 int ret = 0;
674
675 nf_frags.hashfn = nf_hashfn;
676 nf_frags.constructor = ip6_frag_init;
677 nf_frags.destructor = NULL;
678 nf_frags.skb_free = nf_skb_free;
679 nf_frags.qsize = sizeof(struct frag_queue);
680 nf_frags.match = ip6_frag_match;
681 nf_frags.frag_expire = nf_ct_frag6_expire;
682 nf_frags.frags_cache_name = nf_frags_cache_name;
683 ret = inet_frags_init(&nf_frags);
684 if (ret)
685 goto out;
686 ret = register_pernet_subsys(&nf_ct_net_ops);
687 if (ret)
688 inet_frags_fini(&nf_frags);
689
690 out:
691 return ret;
692 }
693
nf_ct_frag6_cleanup(void)694 void nf_ct_frag6_cleanup(void)
695 {
696 unregister_pernet_subsys(&nf_ct_net_ops);
697 inet_frags_fini(&nf_frags);
698 }
699