Initial import

1 files changed, 772 insertions, 0 deletions

diff --git a/net/ipv6/reassembly.c b/net/ipv6/reassembly.c
new file mode 100644
index 000000000..8ffa2c8cc
--- /dev/null
+++ b/net/ipv6/reassembly.c
@@ -0,0 +1,772 @@
+/*
+ *	IPv6 fragment reassembly
+ *	Linux INET6 implementation
+ *
+ *	Authors:
+ *	Pedro Roque		<roque@di.fc.ul.pt>
+ *
+ *	Based on: net/ipv4/ip_fragment.c
+ *
+ *	This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+/*
+ *	Fixes:
+ *	Andi Kleen	Make it work with multiple hosts.
+ *			More RFC compliance.
+ *
+ *      Horst von Brand Add missing #include <linux/string.h>
+ *	Alexey Kuznetsov	SMP races, threading, cleanup.
+ *	Patrick McHardy		LRU queue of frag heads for evictor.
+ *	Mitsuru KANDA @USAGI	Register inet6_protocol{}.
+ *	David Stevens and
+ *	YOSHIFUJI,H. @USAGI	Always remove fragment header to
+ *				calculate ICV correctly.
+ */
+
+#define pr_fmt(fmt) "IPv6: " fmt
+
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/jiffies.h>
+#include <linux/net.h>
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#include <linux/in6.h>
+#include <linux/ipv6.h>
+#include <linux/icmpv6.h>
+#include <linux/random.h>
+#include <linux/jhash.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+
+#include <net/sock.h>
+#include <net/snmp.h>
+
+#include <net/ipv6.h>
+#include <net/ip6_route.h>
+#include <net/protocol.h>
+#include <net/transp_v6.h>
+#include <net/rawv6.h>
+#include <net/ndisc.h>
+#include <net/addrconf.h>
+#include <net/inet_frag.h>
+#include <net/inet_ecn.h>
+
+static const char ip6_frag_cache_name[] = "ip6-frags";
+
+struct ip6frag_skb_cb {
+	struct inet6_skb_parm	h;
+	int			offset;
+};
+
+#define FRAG6_CB(skb)	((struct ip6frag_skb_cb *)((skb)->cb))
+
+static u8 ip6_frag_ecn(const struct ipv6hdr *ipv6h)
+{
+	return 1 << (ipv6_get_dsfield(ipv6h) & INET_ECN_MASK);
+}
+
+static struct inet_frags ip6_frags;
+
+static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
+			  struct net_device *dev);
+
+/*
+ * callers should be careful not to use the hash value outside the ipfrag_lock
+ * as doing so could race with ipfrag_hash_rnd being recalculated.
+ */
+static unsigned int inet6_hash_frag(__be32 id, const struct in6_addr *saddr,
+				    const struct in6_addr *daddr)
+{
+	net_get_random_once(&ip6_frags.rnd, sizeof(ip6_frags.rnd));
+	return jhash_3words(ipv6_addr_hash(saddr), ipv6_addr_hash(daddr),
+			    (__force u32)id, ip6_frags.rnd);
+}
+
+static unsigned int ip6_hashfn(const struct inet_frag_queue *q)
+{
+	const struct frag_queue *fq;
+
+	fq = container_of(q, struct frag_queue, q);
+	return inet6_hash_frag(fq->id, &fq->saddr, &fq->daddr);
+}
+
+bool ip6_frag_match(const struct inet_frag_queue *q, const void *a)
+{
+	const struct frag_queue *fq;
+	const struct ip6_create_arg *arg = a;
+
+	fq = container_of(q, struct frag_queue, q);
+	return	fq->id == arg->id &&
+		fq->user == arg->user &&
+		ipv6_addr_equal(&fq->saddr, arg->src) &&
+		ipv6_addr_equal(&fq->daddr, arg->dst);
+}
+EXPORT_SYMBOL(ip6_frag_match);
+
+void ip6_frag_init(struct inet_frag_queue *q, const void *a)
+{
+	struct frag_queue *fq = container_of(q, struct frag_queue, q);
+	const struct ip6_create_arg *arg = a;
+
+	fq->id = arg->id;
+	fq->user = arg->user;
+	fq->saddr = *arg->src;
+	fq->daddr = *arg->dst;
+	fq->ecn = arg->ecn;
+}
+EXPORT_SYMBOL(ip6_frag_init);
+
+void ip6_expire_frag_queue(struct net *net, struct frag_queue *fq,
+			   struct inet_frags *frags)
+{
+	struct net_device *dev = NULL;
+
+	spin_lock(&fq->q.lock);
+
+	if (fq->q.flags & INET_FRAG_COMPLETE)
+		goto out;
+
+	inet_frag_kill(&fq->q, frags);
+
+	rcu_read_lock();
+	dev = dev_get_by_index_rcu(net, fq->iif);
+	if (!dev)
+		goto out_rcu_unlock;
+
+	IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
+
+	if (fq->q.flags & INET_FRAG_EVICTED)
+		goto out_rcu_unlock;
+
+	IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMTIMEOUT);
+
+	/* Don't send error if the first segment did not arrive. */
+	if (!(fq->q.flags & INET_FRAG_FIRST_IN) || !fq->q.fragments)
+		goto out_rcu_unlock;
+
+	/* But use as source device on which LAST ARRIVED
+	 * segment was received. And do not use fq->dev
+	 * pointer directly, device might already disappeared.
+	 */
+	fq->q.fragments->dev = dev;
+	icmpv6_send(fq->q.fragments, ICMPV6_TIME_EXCEED, ICMPV6_EXC_FRAGTIME, 0);
+out_rcu_unlock:
+	rcu_read_unlock();
+out:
+	spin_unlock(&fq->q.lock);
+	inet_frag_put(&fq->q, frags);
+}
+EXPORT_SYMBOL(ip6_expire_frag_queue);
+
+static void ip6_frag_expire(unsigned long data)
+{
+	struct frag_queue *fq;
+	struct net *net;
+
+	fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q);
+	net = container_of(fq->q.net, struct net, ipv6.frags);
+
+	ip6_expire_frag_queue(net, fq, &ip6_frags);
+}
+
+static struct frag_queue *
+fq_find(struct net *net, __be32 id, const struct in6_addr *src,
+	const struct in6_addr *dst, u8 ecn)
+{
+	struct inet_frag_queue *q;
+	struct ip6_create_arg arg;
+	unsigned int hash;
+
+	arg.id = id;
+	arg.user = IP6_DEFRAG_LOCAL_DELIVER;
+	arg.src = src;
+	arg.dst = dst;
+	arg.ecn = ecn;
+
+	hash = inet6_hash_frag(id, src, dst);
+
+	q = inet_frag_find(&net->ipv6.frags, &ip6_frags, &arg, hash);
+	if (IS_ERR_OR_NULL(q)) {
+		inet_frag_maybe_warn_overflow(q, pr_fmt());
+		return NULL;
+	}
+	return container_of(q, struct frag_queue, q);
+}
+
+static int ip6_frag_queue(struct frag_queue *fq, struct sk_buff *skb,
+			   struct frag_hdr *fhdr, int nhoff)
+{
+	struct sk_buff *prev, *next;
+	struct net_device *dev;
+	int offset, end;
+	struct net *net = dev_net(skb_dst(skb)->dev);
+	u8 ecn;
+
+	if (fq->q.flags & INET_FRAG_COMPLETE)
+		goto err;
+
+	offset = ntohs(fhdr->frag_off) & ~0x7;
+	end = offset + (ntohs(ipv6_hdr(skb)->payload_len) -
+			((u8 *)(fhdr + 1) - (u8 *)(ipv6_hdr(skb) + 1)));
+
+	if ((unsigned int)end > IPV6_MAXPLEN) {
+		IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
+				 IPSTATS_MIB_INHDRERRORS);
+		icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
+				  ((u8 *)&fhdr->frag_off -
+				   skb_network_header(skb)));
+		return -1;
+	}
+
+	ecn = ip6_frag_ecn(ipv6_hdr(skb));
+
+	if (skb->ip_summed == CHECKSUM_COMPLETE) {
+		const unsigned char *nh = skb_network_header(skb);
+		skb->csum = csum_sub(skb->csum,
+				     csum_partial(nh, (u8 *)(fhdr + 1) - nh,
+						  0));
+	}
+
+	/* Is this the final fragment? */
+	if (!(fhdr->frag_off & htons(IP6_MF))) {
+		/* If we already have some bits beyond end
+		 * or have different end, the segment is corrupted.
+		 */
+		if (end < fq->q.len ||
+		    ((fq->q.flags & INET_FRAG_LAST_IN) && end != fq->q.len))
+			goto err;
+		fq->q.flags |= INET_FRAG_LAST_IN;
+		fq->q.len = end;
+	} else {
+		/* Check if the fragment is rounded to 8 bytes.
+		 * Required by the RFC.
+		 */
+		if (end & 0x7) {
+			/* RFC2460 says always send parameter problem in
+			 * this case. -DaveM
+			 */
+			IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
+					 IPSTATS_MIB_INHDRERRORS);
+			icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
+					  offsetof(struct ipv6hdr, payload_len));
+			return -1;
+		}
+		if (end > fq->q.len) {
+			/* Some bits beyond end -> corruption. */
+			if (fq->q.flags & INET_FRAG_LAST_IN)
+				goto err;
+			fq->q.len = end;
+		}
+	}
+
+	if (end == offset)
+		goto err;
+
+	/* Point into the IP datagram 'data' part. */
+	if (!pskb_pull(skb, (u8 *) (fhdr + 1) - skb->data))
+		goto err;
+
+	if (pskb_trim_rcsum(skb, end - offset))
+		goto err;
+
+	/* Find out which fragments are in front and at the back of us
+	 * in the chain of fragments so far.  We must know where to put
+	 * this fragment, right?
+	 */
+	prev = fq->q.fragments_tail;
+	if (!prev || FRAG6_CB(prev)->offset < offset) {
+		next = NULL;
+		goto found;
+	}
+	prev = NULL;
+	for (next = fq->q.fragments; next != NULL; next = next->next) {
+		if (FRAG6_CB(next)->offset >= offset)
+			break;	/* bingo! */
+		prev = next;
+	}
+
+found:
+	/* RFC5722, Section 4, amended by Errata ID : 3089
+	 *                          When reassembling an IPv6 datagram, if
+	 *   one or more its constituent fragments is determined to be an
+	 *   overlapping fragment, the entire datagram (and any constituent
+	 *   fragments) MUST be silently discarded.
+	 */
+
+	/* Check for overlap with preceding fragment. */
+	if (prev &&
+	    (FRAG6_CB(prev)->offset + prev->len) > offset)
+		goto discard_fq;
+
+	/* Look for overlap with succeeding segment. */
+	if (next && FRAG6_CB(next)->offset < end)
+		goto discard_fq;
+
+	FRAG6_CB(skb)->offset = offset;
+
+	/* Insert this fragment in the chain of fragments. */
+	skb->next = next;
+	if (!next)
+		fq->q.fragments_tail = skb;
+	if (prev)
+		prev->next = skb;
+	else
+		fq->q.fragments = skb;
+
+	dev = skb->dev;
+	if (dev) {
+		fq->iif = dev->ifindex;
+		skb->dev = NULL;
+	}
+	fq->q.stamp = skb->tstamp;
+	fq->q.meat += skb->len;
+	fq->ecn |= ecn;
+	add_frag_mem_limit(&fq->q, skb->truesize);
+
+	/* The first fragment.
+	 * nhoffset is obtained from the first fragment, of course.
+	 */
+	if (offset == 0) {
+		fq->nhoffset = nhoff;
+		fq->q.flags |= INET_FRAG_FIRST_IN;
+	}
+
+	if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) &&
+	    fq->q.meat == fq->q.len) {
+		int res;
+		unsigned long orefdst = skb->_skb_refdst;
+
+		skb->_skb_refdst = 0UL;
+		res = ip6_frag_reasm(fq, prev, dev);
+		skb->_skb_refdst = orefdst;
+		return res;
+	}
+
+	skb_dst_drop(skb);
+	return -1;
+
+discard_fq:
+	inet_frag_kill(&fq->q, &ip6_frags);
+err:
+	IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
+			 IPSTATS_MIB_REASMFAILS);
+	kfree_skb(skb);
+	return -1;
+}
+
+/*
+ *	Check if this packet is complete.
+ *	Returns NULL on failure by any reason, and pointer
+ *	to current nexthdr field in reassembled frame.
+ *
+ *	It is called with locked fq, and caller must check that
+ *	queue is eligible for reassembly i.e. it is not COMPLETE,
+ *	the last and the first frames arrived and all the bits are here.
+ */
+static int ip6_frag_reasm(struct frag_queue *fq, struct sk_buff *prev,
+			  struct net_device *dev)
+{
+	struct net *net = container_of(fq->q.net, struct net, ipv6.frags);
+	struct sk_buff *fp, *head = fq->q.fragments;
+	int    payload_len;
+	unsigned int nhoff;
+	int sum_truesize;
+	u8 ecn;
+
+	inet_frag_kill(&fq->q, &ip6_frags);
+
+	ecn = ip_frag_ecn_table[fq->ecn];
+	if (unlikely(ecn == 0xff))
+		goto out_fail;
+
+	/* Make the one we just received the head. */
+	if (prev) {
+		head = prev->next;
+		fp = skb_clone(head, GFP_ATOMIC);
+
+		if (!fp)
+			goto out_oom;
+
+		fp->next = head->next;
+		if (!fp->next)
+			fq->q.fragments_tail = fp;
+		prev->next = fp;
+
+		skb_morph(head, fq->q.fragments);
+		head->next = fq->q.fragments->next;
+
+		consume_skb(fq->q.fragments);
+		fq->q.fragments = head;
+	}
+
+	WARN_ON(head == NULL);
+	WARN_ON(FRAG6_CB(head)->offset != 0);
+
+	/* Unfragmented part is taken from the first segment. */
+	payload_len = ((head->data - skb_network_header(head)) -
+		       sizeof(struct ipv6hdr) + fq->q.len -
+		       sizeof(struct frag_hdr));
+	if (payload_len > IPV6_MAXPLEN)
+		goto out_oversize;
+
+	/* Head of list must not be cloned. */
+	if (skb_unclone(head, GFP_ATOMIC))
+		goto out_oom;
+
+	/* If the first fragment is fragmented itself, we split
+	 * it to two chunks: the first with data and paged part
+	 * and the second, holding only fragments. */
+	if (skb_has_frag_list(head)) {
+		struct sk_buff *clone;
+		int i, plen = 0;
+
+		clone = alloc_skb(0, GFP_ATOMIC);
+		if (!clone)
+			goto out_oom;
+		clone->next = head->next;
+		head->next = clone;
+		skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list;
+		skb_frag_list_init(head);
+		for (i = 0; i < skb_shinfo(head)->nr_frags; i++)
+			plen += skb_frag_size(&skb_shinfo(head)->frags[i]);
+		clone->len = clone->data_len = head->data_len - plen;
+		head->data_len -= clone->len;
+		head->len -= clone->len;
+		clone->csum = 0;
+		clone->ip_summed = head->ip_summed;
+		add_frag_mem_limit(&fq->q, clone->truesize);
+	}
+
+	/* We have to remove fragment header from datagram and to relocate
+	 * header in order to calculate ICV correctly. */
+	nhoff = fq->nhoffset;
+	skb_network_header(head)[nhoff] = skb_transport_header(head)[0];
+	memmove(head->head + sizeof(struct frag_hdr), head->head,
+		(head->data - head->head) - sizeof(struct frag_hdr));
+	head->mac_header += sizeof(struct frag_hdr);
+	head->network_header += sizeof(struct frag_hdr);
+
+	skb_reset_transport_header(head);
+	skb_push(head, head->data - skb_network_header(head));
+
+	sum_truesize = head->truesize;
+	for (fp = head->next; fp;) {
+		bool headstolen;
+		int delta;
+		struct sk_buff *next = fp->next;
+
+		sum_truesize += fp->truesize;
+		if (head->ip_summed != fp->ip_summed)
+			head->ip_summed = CHECKSUM_NONE;
+		else if (head->ip_summed == CHECKSUM_COMPLETE)
+			head->csum = csum_add(head->csum, fp->csum);
+
+		if (skb_try_coalesce(head, fp, &headstolen, &delta)) {
+			kfree_skb_partial(fp, headstolen);
+		} else {
+			if (!skb_shinfo(head)->frag_list)
+				skb_shinfo(head)->frag_list = fp;
+			head->data_len += fp->len;
+			head->len += fp->len;
+			head->truesize += fp->truesize;
+		}
+		fp = next;
+	}
+	sub_frag_mem_limit(&fq->q, sum_truesize);
+
+	head->next = NULL;
+	head->dev = dev;
+	head->tstamp = fq->q.stamp;
+	ipv6_hdr(head)->payload_len = htons(payload_len);
+	ipv6_change_dsfield(ipv6_hdr(head), 0xff, ecn);
+	IP6CB(head)->nhoff = nhoff;
+	IP6CB(head)->flags |= IP6SKB_FRAGMENTED;
+
+	/* Yes, and fold redundant checksum back. 8) */
+	if (head->ip_summed == CHECKSUM_COMPLETE)
+		head->csum = csum_partial(skb_network_header(head),
+					  skb_network_header_len(head),
+					  head->csum);
+
+	rcu_read_lock();
+	IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMOKS);
+	rcu_read_unlock();
+	fq->q.fragments = NULL;
+	fq->q.fragments_tail = NULL;
+	return 1;
+
+out_oversize:
+	net_dbg_ratelimited("ip6_frag_reasm: payload len = %d\n", payload_len);
+	goto out_fail;
+out_oom:
+	net_dbg_ratelimited("ip6_frag_reasm: no memory for reassembly\n");
+out_fail:
+	rcu_read_lock();
+	IP6_INC_STATS_BH(net, __in6_dev_get(dev), IPSTATS_MIB_REASMFAILS);
+	rcu_read_unlock();
+	return -1;
+}
+
+static int ipv6_frag_rcv(struct sk_buff *skb)
+{
+	struct frag_hdr *fhdr;
+	struct frag_queue *fq;
+	const struct ipv6hdr *hdr = ipv6_hdr(skb);
+	struct net *net = dev_net(skb_dst(skb)->dev);
+
+	if (IP6CB(skb)->flags & IP6SKB_FRAGMENTED)
+		goto fail_hdr;
+
+	IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMREQDS);
+
+	/* Jumbo payload inhibits frag. header */
+	if (hdr->payload_len == 0)
+		goto fail_hdr;
+
+	if (!pskb_may_pull(skb, (skb_transport_offset(skb) +
+				 sizeof(struct frag_hdr))))
+		goto fail_hdr;
+
+	hdr = ipv6_hdr(skb);
+	fhdr = (struct frag_hdr *)skb_transport_header(skb);
+
+	if (!(fhdr->frag_off & htons(0xFFF9))) {
+		/* It is not a fragmented frame */
+		skb->transport_header += sizeof(struct frag_hdr);
+		IP6_INC_STATS_BH(net,
+				 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMOKS);
+
+		IP6CB(skb)->nhoff = (u8 *)fhdr - skb_network_header(skb);
+		IP6CB(skb)->flags |= IP6SKB_FRAGMENTED;
+		return 1;
+	}
+
+	fq = fq_find(net, fhdr->identification, &hdr->saddr, &hdr->daddr,
+		     ip6_frag_ecn(hdr));
+	if (fq) {
+		int ret;
+
+		spin_lock(&fq->q.lock);
+
+		ret = ip6_frag_queue(fq, skb, fhdr, IP6CB(skb)->nhoff);
+
+		spin_unlock(&fq->q.lock);
+		inet_frag_put(&fq->q, &ip6_frags);
+		return ret;
+	}
+
+	IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_REASMFAILS);
+	kfree_skb(skb);
+	return -1;
+
+fail_hdr:
+	IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
+			 IPSTATS_MIB_INHDRERRORS);
+	icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, skb_network_header_len(skb));
+	return -1;
+}
+
+static const struct inet6_protocol frag_protocol = {
+	.handler	=	ipv6_frag_rcv,
+	.flags		=	INET6_PROTO_NOPOLICY,
+};
+
+#ifdef CONFIG_SYSCTL
+static int zero;
+
+static struct ctl_table ip6_frags_ns_ctl_table[] = {
+	{
+		.procname	= "ip6frag_high_thresh",
+		.data		= &init_net.ipv6.frags.high_thresh,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &init_net.ipv6.frags.low_thresh
+	},
+	{
+		.procname	= "ip6frag_low_thresh",
+		.data		= &init_net.ipv6.frags.low_thresh,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &zero,
+		.extra2		= &init_net.ipv6.frags.high_thresh
+	},
+	{
+		.procname	= "ip6frag_time",
+		.data		= &init_net.ipv6.frags.timeout,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_jiffies,
+	},
+	{ }
+};
+
+/* secret interval has been deprecated */
+static int ip6_frags_secret_interval_unused;
+static struct ctl_table ip6_frags_ctl_table[] = {
+	{
+		.procname	= "ip6frag_secret_interval",
+		.data		= &ip6_frags_secret_interval_unused,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_jiffies,
+	},
+	{ }
+};
+
+static int __net_init ip6_frags_ns_sysctl_register(struct net *net)
+{
+	struct ctl_table *table;
+	struct ctl_table_header *hdr;
+
+	table = ip6_frags_ns_ctl_table;
+	if (!net_eq(net, &init_net)) {
+		table = kmemdup(table, sizeof(ip6_frags_ns_ctl_table), GFP_KERNEL);
+		if (!table)
+			goto err_alloc;
+
+		table[0].data = &net->ipv6.frags.high_thresh;
+		table[0].extra1 = &net->ipv6.frags.low_thresh;
+		table[0].extra2 = &init_net.ipv6.frags.high_thresh;
+		table[1].data = &net->ipv6.frags.low_thresh;
+		table[1].extra2 = &net->ipv6.frags.high_thresh;
+		table[2].data = &net->ipv6.frags.timeout;
+
+		/* Don't export sysctls to unprivileged users */
+		if (net->user_ns != &init_user_ns)
+			table[0].procname = NULL;
+	}
+
+	hdr = register_net_sysctl(net, "net/ipv6", table);
+	if (!hdr)
+		goto err_reg;
+
+	net->ipv6.sysctl.frags_hdr = hdr;
+	return 0;
+
+err_reg:
+	if (!net_eq(net, &init_net))
+		kfree(table);
+err_alloc:
+	return -ENOMEM;
+}
+
+static void __net_exit ip6_frags_ns_sysctl_unregister(struct net *net)
+{
+	struct ctl_table *table;
+
+	table = net->ipv6.sysctl.frags_hdr->ctl_table_arg;
+	unregister_net_sysctl_table(net->ipv6.sysctl.frags_hdr);
+	if (!net_eq(net, &init_net))
+		kfree(table);
+}
+
+static struct ctl_table_header *ip6_ctl_header;
+
+static int ip6_frags_sysctl_register(void)
+{
+	ip6_ctl_header = register_net_sysctl(&init_net, "net/ipv6",
+			ip6_frags_ctl_table);
+	return ip6_ctl_header == NULL ? -ENOMEM : 0;
+}
+
+static void ip6_frags_sysctl_unregister(void)
+{
+	unregister_net_sysctl_table(ip6_ctl_header);
+}
+#else
+static int ip6_frags_ns_sysctl_register(struct net *net)
+{
+	return 0;
+}
+
+static void ip6_frags_ns_sysctl_unregister(struct net *net)
+{
+}
+
+static int ip6_frags_sysctl_register(void)
+{
+	return 0;
+}
+
+static void ip6_frags_sysctl_unregister(void)
+{
+}
+#endif
+
+static int __net_init ipv6_frags_init_net(struct net *net)
+{
+	net->ipv6.frags.high_thresh = IPV6_FRAG_HIGH_THRESH;
+	net->ipv6.frags.low_thresh = IPV6_FRAG_LOW_THRESH;
+	net->ipv6.frags.timeout = IPV6_FRAG_TIMEOUT;
+
+	inet_frags_init_net(&net->ipv6.frags);
+
+	return ip6_frags_ns_sysctl_register(net);
+}
+
+static void __net_exit ipv6_frags_exit_net(struct net *net)
+{
+	ip6_frags_ns_sysctl_unregister(net);
+	inet_frags_exit_net(&net->ipv6.frags, &ip6_frags);
+}
+
+static struct pernet_operations ip6_frags_ops = {
+	.init = ipv6_frags_init_net,
+	.exit = ipv6_frags_exit_net,
+};
+
+int __init ipv6_frag_init(void)
+{
+	int ret;
+
+	ret = inet6_add_protocol(&frag_protocol, IPPROTO_FRAGMENT);
+	if (ret)
+		goto out;
+
+	ret = ip6_frags_sysctl_register();
+	if (ret)
+		goto err_sysctl;
+
+	ret = register_pernet_subsys(&ip6_frags_ops);
+	if (ret)
+		goto err_pernet;
+
+	ip6_frags.hashfn = ip6_hashfn;
+	ip6_frags.constructor = ip6_frag_init;
+	ip6_frags.destructor = NULL;
+	ip6_frags.skb_free = NULL;
+	ip6_frags.qsize = sizeof(struct frag_queue);
+	ip6_frags.match = ip6_frag_match;
+	ip6_frags.frag_expire = ip6_frag_expire;
+	ip6_frags.frags_cache_name = ip6_frag_cache_name;
+	ret = inet_frags_init(&ip6_frags);
+	if (ret)
+		goto err_pernet;
+out:
+	return ret;
+
+err_pernet:
+	ip6_frags_sysctl_unregister();
+err_sysctl:
+	inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
+	goto out;
+}
+
+void ipv6_frag_exit(void)
+{
+	inet_frags_fini(&ip6_frags);
+	ip6_frags_sysctl_unregister();
+	unregister_pernet_subsys(&ip6_frags_ops);
+	inet6_del_protocol(&frag_protocol, IPPROTO_FRAGMENT);
+}