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#include <net/inet_ecn.h>
 62
 63static const char ip6_frag_cache_name[] = "ip6-frags";
 64
 65struct ip6frag_skb_cb {
 
 66	struct inet6_skb_parm	h;
 67	int			offset;
 68};
 69
 70#define FRAG6_CB(skb)	((struct ip6frag_skb_cb *)((skb)->cb))
 
 71
 72static u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h)
 
 
 
 
 73{
 74	return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK);
 75}
 
 
 
 
 
 
 
 
 
 76
 77static struct inet_frags ip6_frags;
 78
 
 
 
 
 
 
 
 
 
 
 79static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
 80			  struct net_device *dev);
 81
 82/*
 83 * callers should be careful not to use the hash value outside the ipfrag_lock
 84 * as doing so could race with ipfrag_hash_rnd being recalculated.
 85 */
 86static unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
 87				    const struct in6_addr *daddr)
 88{
 89	net_get_random_once(&ip6_frags.rnd, sizeof(ip6_frags.rnd));
 90	return jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr),
 91			    (__force u32)id, ip6_frags.rnd);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 92}
 
 93
 94static unsigned int ip6_hashfn(const struct inet_frag_queue *q)
 95{
 96	const struct frag_queue *fq;
 97
 98	fq = container_of(q, struct frag_queue, q);
 99	return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr);
100}
101
102bool ip6_frag_match(const struct inet_frag_queue *q, const void *a)
103{
104	const struct frag_queue *fq;
105	const struct ip6_create_arg *arg = a;
106
107	fq = container_of(q, struct frag_queue, q);
108	return	fq->id == arg->id &&
109		fq->user == arg->user &&
110		ipv6_addr_equal(&fq->saddr, arg->src) &&
111		ipv6_addr_equal(&fq->daddr, arg->dst) &&
112		(arg->iif == fq->iif ||
113		 !(ipv6_addr_type(arg->dst) & (IPV6_ADDR_MULTICAST |
114					       IPV6_ADDR_LINKLOCAL)));
115}
116EXPORT_SYMBOL(ip6_frag_match);
117
118void ip6_frag_init(struct inet_frag_queue *q, const void *a)
119{
120	struct frag_queue *fq = container_of(q, struct frag_queue, q);
121	const struct ip6_create_arg *arg = a;
122
123	fq->id = arg->id;
124	fq->user = arg->user;
125	fq->saddr = *arg->src;
126	fq->daddr = *arg->dst;
127	fq->ecn = arg->ecn;
128}
129EXPORT_SYMBOL(ip6_frag_init);
130
131void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
132			   struct inet_frags *frags)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
133{
 
134	struct net_device *dev = NULL;
 
 
 
135
136	spin_lock(&fq->q.lock);
137
138	if (fq->q.flags & INET_FRAG_COMPLETE)
139		goto out;
140
141	inet_frag_kill(&fq->q, frags);
142
 
143	rcu_read_lock();
144	dev = dev_get_by_index_rcu(net, fq->iif);
145	if (!dev)
146		goto out_rcu_unlock;
147
148	IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
149
150	if (inet_frag_evicting(&fq->q))
151		goto out_rcu_unlock;
152
153	IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
 
154
155	/* Don't send error if the first segment did not arrive. */
156	if (!(fq->q.flags & INET_FRAG_FIRST_IN) || !fq->q.fragments)
157		goto out_rcu_unlock;
158
159	/* But use as source device on which LAST ARRIVED
160	 * segment was received. And do not use fq->dev
161	 * pointer directly, device might already disappeared.
 
162	 */
163	fq->q.fragments->dev = dev;
164	icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
165out_rcu_unlock:
166	rcu_read_unlock();
167out:
168	spin_unlock(&fq->q.lock);
169	inet_frag_put(&fq->q, frags);
170}
171EXPORT_SYMBOL(ip6_expire_frag_queue);
172
173static void ip6_frag_expire(unsigned long data)
174{
175	struct frag_queue *fq;
176	struct net *net;
177
178	fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
179	net = container_of(fq->q.net, struct net, ipv6.frags);
180
181	ip6_expire_frag_queue(net, fq, &ip6_frags);
182}
183
184static struct frag_queue *
185fq_find(struct net *net, __be32 id, const struct in6_addr *src,
186	const struct in6_addr *dst, int iif, u8 ecn)
187{
188	struct inet_frag_queue *q;
189	struct ip6_create_arg arg;
190	unsigned int hash;
191
192	arg.id = id;
193	arg.user = IP6_DEFRAG_LOCAL_DELIVER;
194	arg.src = src;
195	arg.dst = dst;
196	arg.iif = iif;
197	arg.ecn = ecn;
198
199	hash = inet6_hash_frag(id, src, dst);
 
200
201	q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash);
202	if (IS_ERR_OR_NULL(q)) {
203		inet_frag_maybe_warn_overflow(q, pr_fmt());
204		return NULL;
205	}
206	return container_of(q, struct frag_queue, q);
207}
208
209static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
210			   struct frag_hdr *fhdr, int nhoff)
211{
212	struct sk_buff *prev, *next;
213	struct net_device *dev;
214	int offset, end;
215	struct net *net = dev_net(skb_dst(skb)->dev);
216	u8 ecn;
217
218	if (fq->q.flags & INET_FRAG_COMPLETE)
219		goto err;
220
221	offset = ntohs(fhdr->frag_off) & ~0x7;
222	end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
223			((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
224
225	if ((unsigned int)end > IPV6_MAXPLEN) {
226		IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
227				 IPSTATS_MIB_INHDRERRORS);
228		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
229				  ((u8 *)&fhdr->frag_off -
230				   skb_network_header(skb)));
231		return -1;
232	}
233
234	ecn = ip6_frag_ecn(ipv6_hdr(skb));
235
236	if (skb->ip_summed == CHECKSUM_COMPLETE) {
237		const unsigned char *nh = skb_network_header(skb);
238		skb->csum = csum_sub(skb->csum,
239				     csum_partial(nh, (u8 *)(fhdr + 1) - nh,
240						  0));
241	}
242
243	/* Is this the final fragment? */
244	if (!(fhdr->frag_off & htons(IP6_MF))) {
245		/* If we already have some bits beyond end
246		 * or have different end, the segment is corrupted.
247		 */
248		if (end < fq->q.len ||
249		    ((fq->q.flags & INET_FRAG_LAST_IN) && end != fq->q.len))
250			goto err;
251		fq->q.flags |= INET_FRAG_LAST_IN;
252		fq->q.len = end;
253	} else {
254		/* Check if the fragment is rounded to 8 bytes.
255		 * Required by the RFC.
256		 */
257		if (end & 0x7) {
258			/* RFC2460 says always send parameter problem in
259			 * this case. -DaveM
260			 */
261			IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
262					 IPSTATS_MIB_INHDRERRORS);
263			icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
264					  offsetof(struct ipv6hdr, payload_len));
265			return -1;
266		}
267		if (end > fq->q.len) {
268			/* Some bits beyond end -> corruption. */
269			if (fq->q.flags & INET_FRAG_LAST_IN)
270				goto err;
271			fq->q.len = end;
272		}
273	}
274
275	if (end == offset)
276		goto err;
277
278	/* Point into the IP datagram 'data' part. */
279	if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
280		goto err;
281
282	if (pskb_trim_rcsum(skb, end - offset))
283		goto err;
284
285	/* Find out which fragments are in front and at the back of us
286	 * in the chain of fragments so far.  We must know where to put
287	 * this fragment, right?
288	 */
289	prev = fq->q.fragments_tail;
290	if (!prev || FRAG6_CB(prev)->offset < offset) {
291		next = NULL;
292		goto found;
293	}
294	prev = NULL;
295	for (next = fq->q.fragments; next != NULL; next = next->next) {
296		if (FRAG6_CB(next)->offset >= offset)
297			break;	/* bingo! */
298		prev = next;
299	}
300
301found:
302	/* RFC5722, Section 4, amended by Errata ID : 3089
303	 *                          When reassembling an IPv6 datagram, if
304	 *   one or more its constituent fragments is determined to be an
305	 *   overlapping fragment, the entire datagram (and any constituent
306	 *   fragments) MUST be silently discarded.
 
307	 */
308
309	/* Check for overlap with preceding fragment. */
310	if (prev &&
311	    (FRAG6_CB(prev)->offset + prev->len) > offset)
312		goto discard_fq;
313
314	/* Look for overlap with succeeding segment. */
315	if (next && FRAG6_CB(next)->offset < end)
316		goto discard_fq;
317
318	FRAG6_CB(skb)->offset = offset;
319
320	/* Insert this fragment in the chain of fragments. */
321	skb->next = next;
322	if (!next)
323		fq->q.fragments_tail = skb;
324	if (prev)
325		prev->next = skb;
326	else
327		fq->q.fragments = skb;
328
329	dev = skb->dev;
330	if (dev) {
331		fq->iif = dev->ifindex;
332		skb->dev = NULL;
333	}
334	fq->q.stamp = skb->tstamp;
335	fq->q.meat += skb->len;
336	fq->ecn |= ecn;
337	add_frag_mem_limit(fq->q.net, skb->truesize);
338
339	/* The first fragment.
340	 * nhoffset is obtained from the first fragment, of course.
341	 */
342	if (offset == 0) {
343		fq->nhoffset = nhoff;
344		fq->q.flags |= INET_FRAG_FIRST_IN;
345	}
346
347	if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
348	    fq->q.meat == fq->q.len) {
349		int res;
350		unsigned long orefdst = skb->_skb_refdst;
351
352		skb->_skb_refdst = 0UL;
353		res = ip6_frag_reasm(fq, prev, dev);
354		skb->_skb_refdst = orefdst;
355		return res;
356	}
357
358	skb_dst_drop(skb);
359	return -1;
360
361discard_fq:
362	inet_frag_kill(&fq->q, &ip6_frags);
363err:
364	IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
365			 IPSTATS_MIB_REASMFAILS);
366	kfree_skb(skb);
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 */
379static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
380			  struct net_device *dev)
381{
382	struct net *net = container_of(fq->q.net, struct net, ipv6.frags);
383	struct sk_buff *fp, *head = fq->q.fragments;
384	int    payload_len;
385	unsigned int nhoff;
386	int sum_truesize;
387	u8 ecn;
388
389	inet_frag_kill(&fq->q, &ip6_frags);
390
391	ecn = ip_frag_ecn_table[fq->ecn];
392	if (unlikely(ecn == 0xff))
393		goto out_fail;
394
395	/* Make the one we just received the head. */
396	if (prev) {
397		head = prev->next;
398		fp = skb_clone(head, GFP_ATOMIC);
399
400		if (!fp)
401			goto out_oom;
402
403		fp->next = head->next;
404		if (!fp->next)
405			fq->q.fragments_tail = fp;
406		prev->next = fp;
407
408		skb_morph(head, fq->q.fragments);
409		head->next = fq->q.fragments->next;
410
411		consume_skb(fq->q.fragments);
412		fq->q.fragments = head;
413	}
414
415	WARN_ON(head == NULL);
416	WARN_ON(FRAG6_CB(head)->offset != 0);
417
418	/* Unfragmented part is taken from the first segment. */
419	payload_len = ((head->data - skb_network_header(head)) -
420		       sizeof(struct ipv6hdr) + fq->q.len -
421		       sizeof(struct frag_hdr));
422	if (payload_len > IPV6_MAXPLEN)
423		goto out_oversize;
424
425	/* Head of list must not be cloned. */
426	if (skb_unclone(head, GFP_ATOMIC))
427		goto out_oom;
428
429	/* If the first fragment is fragmented itself, we split
430	 * it to two chunks: the first with data and paged part
431	 * and the second, holding only fragments. */
432	if (skb_has_frag_list(head)) {
433		struct sk_buff *clone;
434		int i, plen = 0;
435
436		clone = alloc_skb(0, GFP_ATOMIC);
437		if (!clone)
438			goto out_oom;
439		clone->next = head->next;
440		head->next = clone;
441		skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
442		skb_frag_list_init(head);
443		for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
444			plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
445		clone->len = clone->data_len = head->data_len - plen;
446		head->data_len -= clone->len;
447		head->len -= clone->len;
448		clone->csum = 0;
449		clone->ip_summed = head->ip_summed;
450		add_frag_mem_limit(fq->q.net, clone->truesize);
451	}
452
453	/* We have to remove fragment header from datagram and to relocate
454	 * header in order to calculate ICV correctly. */
455	nhoff = fq->nhoffset;
456	skb_network_header(head)[nhoff] = skb_transport_header(head)[0];
457	memmove(head->head + sizeof(struct frag_hdr), head->head,
458		(head->data - head->head) - sizeof(struct frag_hdr));
459	head->mac_header += sizeof(struct frag_hdr);
460	head->network_header += sizeof(struct frag_hdr);
461
 
462	skb_reset_transport_header(head);
463	skb_push(head, head->data - skb_network_header(head));
464
465	sum_truesize = head->truesize;
466	for (fp = head->next; fp;) {
467		bool headstolen;
468		int delta;
469		struct sk_buff *next = fp->next;
470
471		sum_truesize += fp->truesize;
472		if (head->ip_summed != fp->ip_summed)
473			head->ip_summed = CHECKSUM_NONE;
474		else if (head->ip_summed == CHECKSUM_COMPLETE)
475			head->csum = csum_add(head->csum, fp->csum);
476
477		if (skb_try_coalesce(head, fp, &headstolen, &delta)) {
478			kfree_skb_partial(fp, headstolen);
479		} else {
480			if (!skb_shinfo(head)->frag_list)
481				skb_shinfo(head)->frag_list = fp;
482			head->data_len += fp->len;
483			head->len += fp->len;
484			head->truesize += fp->truesize;
485		}
486		fp = next;
487	}
488	sub_frag_mem_limit(fq->q.net, sum_truesize);
489
490	head->next = NULL;
491	head->dev = dev;
492	head->tstamp = fq->q.stamp;
493	ipv6_hdr(head)->payload_len = htons(payload_len);
494	ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn);
495	IP6CB(head)->nhoff = nhoff;
496	IP6CB(head)->flags |= IP6SKB_FRAGMENTED;
497
498	/* Yes, and fold redundant checksum back. 8) */
499	skb_postpush_rcsum(head, skb_network_header(head),
500			   skb_network_header_len(head));
 
 
501
502	rcu_read_lock();
503	IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
504	rcu_read_unlock();
505	fq->q.fragments = NULL;
506	fq->q.fragments_tail = NULL;
507	return 1;
508
509out_oversize:
510	net_dbg_ratelimited("ip6_frag_reasm: payload len = %d\n", payload_len);
 
511	goto out_fail;
512out_oom:
513	net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n");
 
514out_fail:
515	rcu_read_lock();
516	IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
517	rcu_read_unlock();
518	return -1;
519}
520
521static int ipv6_frag_rcv(struct sk_buff *skb)
522{
523	struct frag_hdr *fhdr;
524	struct frag_queue *fq;
525	const struct ipv6hdr *hdr = ipv6_hdr(skb);
526	struct net *net = dev_net(skb_dst(skb)->dev);
527
528	if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED)
529		goto fail_hdr;
530
531	IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS);
532
533	/* Jumbo payload inhibits frag. header */
534	if (hdr->payload_len == 0)
535		goto fail_hdr;
536
537	if (!pskb_may_pull(skb, (skb_transport_offset(skb) +
538				 sizeof(struct frag_hdr))))
539		goto fail_hdr;
540
541	hdr = ipv6_hdr(skb);
542	fhdr = (struct frag_hdr *)skb_transport_header(skb);
543
544	if (!(fhdr->frag_off & htons(0xFFF9))) {
545		/* It is not a fragmented frame */
546		skb->transport_header += sizeof(struct frag_hdr);
547		IP6_INC_STATS_BH(net,
548				 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS);
549
550		IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb);
551		IP6CB(skb)->flags |= IP6SKB_FRAGMENTED;
552		return 1;
553	}
554
555	fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr,
556		     skb->dev ? skb->dev->ifindex : 0, ip6_frag_ecn(hdr));
557	if (fq) {
 
 
558		int ret;
559
560		spin_lock(&fq->q.lock);
561
562		ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
563
564		spin_unlock(&fq->q.lock);
565		inet_frag_put(&fq->q, &ip6_frags);
566		return ret;
567	}
568
569	IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS);
570	kfree_skb(skb);
571	return -1;
572
573fail_hdr:
574	IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
575			 IPSTATS_MIB_INHDRERRORS);
576	icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb));
577	return -1;
578}
579
580static const struct inet6_protocol frag_protocol = {
 
581	.handler	=	ipv6_frag_rcv,
582	.flags		=	INET6_PROTO_NOPOLICY,
583};
584
585#ifdef CONFIG_SYSCTL
586static int zero;
587
588static struct ctl_table ip6_frags_ns_ctl_table[] = {
589	{
590		.procname	= "ip6frag_high_thresh",
591		.data		= &init_net.ipv6.frags.high_thresh,
592		.maxlen		= sizeof(int),
593		.mode		= 0644,
594		.proc_handler	= proc_dointvec_minmax,
595		.extra1		= &init_net.ipv6.frags.low_thresh
596	},
597	{
598		.procname	= "ip6frag_low_thresh",
599		.data		= &init_net.ipv6.frags.low_thresh,
600		.maxlen		= sizeof(int),
601		.mode		= 0644,
602		.proc_handler	= proc_dointvec_minmax,
603		.extra1		= &zero,
604		.extra2		= &init_net.ipv6.frags.high_thresh
605	},
606	{
607		.procname	= "ip6frag_time",
608		.data		= &init_net.ipv6.frags.timeout,
609		.maxlen		= sizeof(int),
610		.mode		= 0644,
611		.proc_handler	= proc_dointvec_jiffies,
612	},
613	{ }
614};
615
616/* secret interval has been deprecated */
617static int ip6_frags_secret_interval_unused;
618static struct ctl_table ip6_frags_ctl_table[] = {
619	{
620		.procname	= "ip6frag_secret_interval",
621		.data		= &ip6_frags_secret_interval_unused,
622		.maxlen		= sizeof(int),
623		.mode		= 0644,
624		.proc_handler	= proc_dointvec_jiffies,
625	},
626	{ }
627};
628
629static int __net_init ip6_frags_ns_sysctl_register(struct net *net)
630{
631	struct ctl_table *table;
632	struct ctl_table_header *hdr;
633
634	table = ip6_frags_ns_ctl_table;
635	if (!net_eq(net, &init_net)) {
636		table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL);
637		if (!table)
638			goto err_alloc;
639
640		table[0].data = &net->ipv6.frags.high_thresh;
641		table[0].extra1 = &net->ipv6.frags.low_thresh;
642		table[0].extra2 = &init_net.ipv6.frags.high_thresh;
643		table[1].data = &net->ipv6.frags.low_thresh;
644		table[1].extra2 = &net->ipv6.frags.high_thresh;
645		table[2].data = &net->ipv6.frags.timeout;
646
647		/* Don't export sysctls to unprivileged users */
648		if (net->user_ns != &init_user_ns)
649			table[0].procname = NULL;
650	}
651
652	hdr = register_net_sysctl(net, "net/ipv6", table);
653	if (!hdr)
654		goto err_reg;
655
656	net->ipv6.sysctl.frags_hdr = hdr;
657	return 0;
658
659err_reg:
660	if (!net_eq(net, &init_net))
661		kfree(table);
662err_alloc:
663	return -ENOMEM;
664}
665
666static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net)
667{
668	struct ctl_table *table;
669
670	table = net->ipv6.sysctl.frags_hdr->ctl_table_arg;
671	unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr);
672	if (!net_eq(net, &init_net))
673		kfree(table);
674}
675
676static struct ctl_table_header *ip6_ctl_header;
677
678static int ip6_frags_sysctl_register(void)
679{
680	ip6_ctl_header = register_net_sysctl(&init_net, "net/ipv6",
681			ip6_frags_ctl_table);
682	return ip6_ctl_header == NULL ? -ENOMEM : 0;
683}
684
685static void ip6_frags_sysctl_unregister(void)
686{
687	unregister_net_sysctl_table(ip6_ctl_header);
688}
689#else
690static int ip6_frags_ns_sysctl_register(struct net *net)
691{
692	return 0;
693}
694
695static void ip6_frags_ns_sysctl_unregister(struct net *net)
696{
697}
698
699static int ip6_frags_sysctl_register(void)
700{
701	return 0;
702}
703
704static void ip6_frags_sysctl_unregister(void)
705{
706}
707#endif
708
709static int __net_init ipv6_frags_init_net(struct net *net)
710{
711	int res;
712
713	net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH;
714	net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH;
715	net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT;
716
717	res = inet_frags_init_net(&net->ipv6.frags);
718	if (res)
719		return res;
720	res = ip6_frags_ns_sysctl_register(net);
721	if (res)
722		inet_frags_uninit_net(&net->ipv6.frags);
723	return res;
724}
725
726static void __net_exit ipv6_frags_exit_net(struct net *net)
727{
728	ip6_frags_ns_sysctl_unregister(net);
729	inet_frags_exit_net(&net->ipv6.frags, &ip6_frags);
730}
731
732static struct pernet_operations ip6_frags_ops = {
733	.init = ipv6_frags_init_net,
734	.exit = ipv6_frags_exit_net,
735};
736
737int __init ipv6_frag_init(void)
738{
739	int ret;
740
741	ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT);
742	if (ret)
743		goto out;
744
745	ret = ip6_frags_sysctl_register();
746	if (ret)
747		goto err_sysctl;
748
749	ret = register_pernet_subsys(&ip6_frags_ops);
750	if (ret)
751		goto err_pernet;
752
753	ip6_frags.hashfn = ip6_hashfn;
754	ip6_frags.constructor = ip6_frag_init;
755	ip6_frags.destructor = NULL;
 
756	ip6_frags.qsize = sizeof(struct frag_queue);
757	ip6_frags.match = ip6_frag_match;
758	ip6_frags.frag_expire = ip6_frag_expire;
759	ip6_frags.frags_cache_name = ip6_frag_cache_name;
760	ret = inet_frags_init(&ip6_frags);
761	if (ret)
762		goto err_pernet;
763out:
764	return ret;
765
766err_pernet:
767	ip6_frags_sysctl_unregister();
768err_sysctl:
769	inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
770	goto out;
771}
772
773void ipv6_frag_exit(void)
774{
775	inet_frags_fini(&ip6_frags);
776	ip6_frags_sysctl_unregister();
777	unregister_pernet_subsys(&ip6_frags_ops);
778	inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
779}