[linux-block.git] / net / ipv6 / ip6_input.c

/*
 *	IPv6 input
 *	Linux INET6 implementation
 *
 *	Authors:
 *	Pedro Roque		<roque@di.fc.ul.pt>
 *	Ian P. Morris		<I.P.Morris@soton.ac.uk>
 *
 *	Based in linux/net/ipv4/ip_input.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.
 */
/* Changes
 *
 * 	Mitsuru KANDA @USAGI and
 * 	YOSHIFUJI Hideaki @USAGI: Remove ipv6_parse_exthdrs().
 */

#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/in6.h>
#include <linux/icmpv6.h>
#include <linux/mroute6.h>
#include <linux/slab.h>

#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>

#include <net/sock.h>
#include <net/snmp.h>

#include <net/ipv6.h>
#include <net/protocol.h>
#include <net/transp_v6.h>
#include <net/rawv6.h>
#include <net/ndisc.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
#include <net/xfrm.h>


inline int ip6_rcv_finish( struct sk_buff *skb)
{
	if (skb_dst(skb) == NULL)
		ip6_route_input(skb);

	return dst_input(skb);
}

int ipv6_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
{
	const struct ipv6hdr *hdr;
	u32 		pkt_len;
	struct inet6_dev *idev;
	struct net *net = dev_net(skb->dev);

	if (skb->pkt_type == PACKET_OTHERHOST) {
		kfree_skb(skb);
		return NET_RX_DROP;
	}

	rcu_read_lock();

	idev = __in6_dev_get(skb->dev);

	IP6_UPD_PO_STATS_BH(net, idev, IPSTATS_MIB_IN, skb->len);

	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL ||
	    !idev || unlikely(idev->cnf.disable_ipv6)) {
		IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
		goto drop;
	}

	memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));

	/*
	 * Store incoming device index. When the packet will
	 * be queued, we cannot refer to skb->dev anymore.
	 *
	 * BTW, when we send a packet for our own local address on a
	 * non-loopback interface (e.g. ethX), it is being delivered
	 * via the loopback interface (lo) here; skb->dev = loopback_dev.
	 * It, however, should be considered as if it is being
	 * arrived via the sending interface (ethX), because of the
	 * nature of scoping architecture. --yoshfuji
	 */
	IP6CB(skb)->iif = skb_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex;

	if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
		goto err;

	hdr = ipv6_hdr(skb);

	if (hdr->version != 6)
		goto err;

	/*
	 * RFC4291 2.5.3
	 * A packet received on an interface with a destination address
	 * of loopback must be dropped.
	 */
	if (!(dev->flags & IFF_LOOPBACK) &&
	    ipv6_addr_loopback(&hdr->daddr))
		goto err;

	/*
	 * RFC4291 2.7
	 * Multicast addresses must not be used as source addresses in IPv6
	 * packets or appear in any Routing header.
	 */
	if (ipv6_addr_is_multicast(&hdr->saddr))
		goto err;

	skb->transport_header = skb->network_header + sizeof(*hdr);
	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);

	pkt_len = ntohs(hdr->payload_len);

	/* pkt_len may be zero if Jumbo payload option is present */
	if (pkt_len || hdr->nexthdr != NEXTHDR_HOP) {
		if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
			IP6_INC_STATS_BH(net,
					 idev, IPSTATS_MIB_INTRUNCATEDPKTS);
			goto drop;
		}
		if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
			IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
			goto drop;
		}
		hdr = ipv6_hdr(skb);
	}

	if (hdr->nexthdr == NEXTHDR_HOP) {
		if (ipv6_parse_hopopts(skb) < 0) {
			IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
			rcu_read_unlock();
			return NET_RX_DROP;
		}
	}

	rcu_read_unlock();

	/* Must drop socket now because of tproxy. */
	skb_orphan(skb);

	return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, dev, NULL,
		       ip6_rcv_finish);
err:
	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
drop:
	rcu_read_unlock();
	kfree_skb(skb);
	return NET_RX_DROP;
}

/*
 *	Deliver the packet to the host
 */


static int ip6_input_finish(struct sk_buff *skb)
{
	const struct inet6_protocol *ipprot;
	unsigned int nhoff;
	int nexthdr, raw;
	u8 hash;
	struct inet6_dev *idev;
	struct net *net = dev_net(skb_dst(skb)->dev);

	/*
	 *	Parse extension headers
	 */

	rcu_read_lock();
resubmit:
	idev = ip6_dst_idev(skb_dst(skb));
	if (!pskb_pull(skb, skb_transport_offset(skb)))
		goto discard;
	nhoff = IP6CB(skb)->nhoff;
	nexthdr = skb_network_header(skb)[nhoff];

	raw = raw6_local_deliver(skb, nexthdr);

	hash = nexthdr & (MAX_INET_PROTOS - 1);
	if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {
		int ret;

		if (ipprot->flags & INET6_PROTO_FINAL) {
			const struct ipv6hdr *hdr;

			/* Free reference early: we don't need it any more,
			   and it may hold ip_conntrack module loaded
			   indefinitely. */
			nf_reset(skb);

			skb_postpull_rcsum(skb, skb_network_header(skb),
					   skb_network_header_len(skb));
			hdr = ipv6_hdr(skb);
			if (ipv6_addr_is_multicast(&hdr->daddr) &&
			    !ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
			    &hdr->saddr) &&
			    !ipv6_is_mld(skb, nexthdr))
				goto discard;
		}
		if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
		    !xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
			goto discard;

		ret = ipprot->handler(skb);
		if (ret > 0)
			goto resubmit;
		else if (ret == 0)
			IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
	} else {
		if (!raw) {
			if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
				IP6_INC_STATS_BH(net, idev,
						 IPSTATS_MIB_INUNKNOWNPROTOS);
				icmpv6_send(skb, ICMPV6_PARAMPROB,
					    ICMPV6_UNK_NEXTHDR, nhoff);
			}
		} else
			IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
		kfree_skb(skb);
	}
	rcu_read_unlock();
	return 0;

discard:
	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
	rcu_read_unlock();
	kfree_skb(skb);
	return 0;
}


int ip6_input(struct sk_buff *skb)
{
	return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN, skb, skb->dev, NULL,
		       ip6_input_finish);
}

int ip6_mc_input(struct sk_buff *skb)
{
	const struct ipv6hdr *hdr;
	int deliver;

	IP6_UPD_PO_STATS_BH(dev_net(skb_dst(skb)->dev),
			 ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST,
			 skb->len);

	hdr = ipv6_hdr(skb);
	deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);

#ifdef CONFIG_IPV6_MROUTE
	/*
	 *      IPv6 multicast router mode is now supported ;)
	 */
	if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
	    !(ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) &&
	    likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
		/*
		 * Okay, we try to forward - split and duplicate
		 * packets.
		 */
		struct sk_buff *skb2;
		struct inet6_skb_parm *opt = IP6CB(skb);

		/* Check for MLD */
		if (unlikely(opt->ra)) {
			/* Check if this is a mld message */
			u8 *ptr = skb_network_header(skb) + opt->ra;
			struct icmp6hdr *icmp6;
			u8 nexthdr = hdr->nexthdr;
			__be16 frag_off;
			int offset;

			/* Check if the value of Router Alert
			 * is for MLD (0x0000).
			 */
			if ((ptr[2] | ptr[3]) == 0) {
				deliver = 0;

				if (!ipv6_ext_hdr(nexthdr)) {
					/* BUG */
					goto out;
				}
				offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
							  &nexthdr, &frag_off);
				if (offset < 0)
					goto out;

				if (nexthdr != IPPROTO_ICMPV6)
					goto out;

				if (!pskb_may_pull(skb, (skb_network_header(skb) +
						   offset + 1 - skb->data)))
					goto out;

				icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);

				switch (icmp6->icmp6_type) {
				case ICMPV6_MGM_QUERY:
				case ICMPV6_MGM_REPORT:
				case ICMPV6_MGM_REDUCTION:
				case ICMPV6_MLD2_REPORT:
					deliver = 1;
					break;
				}
				goto out;
			}
			/* unknown RA - process it normally */
		}

		if (deliver)
			skb2 = skb_clone(skb, GFP_ATOMIC);
		else {
			skb2 = skb;
			skb = NULL;
		}

		if (skb2) {
			ip6_mr_input(skb2);
		}
	}
out:
#endif
	if (likely(deliver))
		ip6_input(skb);
	else {
		/* discard */
		kfree_skb(skb);
	}

	return 0;
}
Commit	Line	Data
1da177e4 LT	1	/*
1da177e4 LT	2	* IPv6 input
1ab1457c	3	* Linux INET6 implementation
1da177e4 LT	4	*
	5	* Authors:
	6	* Pedro Roque <roque@di.fc.ul.pt>
	7	* Ian P. Morris <I.P.Morris@soton.ac.uk>
	8	*
1da177e4 LT	9	* Based in linux/net/ipv4/ip_input.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	/* Changes
	17	*
	18	* Mitsuru KANDA @USAGI and
	19	* YOSHIFUJI Hideaki @USAGI: Remove ipv6_parse_exthdrs().
	20	*/
	21
	22	#include <linux/errno.h>
	23	#include <linux/types.h>
	24	#include <linux/socket.h>
	25	#include <linux/sockios.h>
1da177e4 LT	26	#include <linux/net.h>
	27	#include <linux/netdevice.h>
	28	#include <linux/in6.h>
	29	#include <linux/icmpv6.h>
7bc570c8	30	#include <linux/mroute6.h>
5a0e3ad6	31	#include <linux/slab.h>
1da177e4 LT	32
	33	#include <linux/netfilter.h>
	34	#include <linux/netfilter_ipv6.h>
	35
	36	#include <net/sock.h>
	37	#include <net/snmp.h>
	38
	39	#include <net/ipv6.h>
	40	#include <net/protocol.h>
	41	#include <net/transp_v6.h>
	42	#include <net/rawv6.h>
	43	#include <net/ndisc.h>
	44	#include <net/ip6_route.h>
	45	#include <net/addrconf.h>
	46	#include <net/xfrm.h>
	47
	48
	49
1ab1457c	50	inline int ip6_rcv_finish( struct sk_buff *skb)
1da177e4	51	{
adf30907	52	if (skb_dst(skb) == NULL)
1da177e4 LT	53	ip6_route_input(skb);
	54
	55	return dst_input(skb);
	56	}
	57
f2ccd8fa	58	int ipv6_rcv(struct sk_buff skb, struct net_device dev, struct packet_type pt, struct net_device orig_dev)
1da177e4	59	{
b71d1d42	60	const struct ipv6hdr *hdr;
1da177e4	61	u32 pkt_len;
a11d206d	62	struct inet6_dev *idev;
483a47d2	63	struct net *net = dev_net(skb->dev);
1da177e4	64
a11d206d YH	65	if (skb->pkt_type == PACKET_OTHERHOST) {
a11d206d YH	66	kfree_skb(skb);
5c91face	67	return NET_RX_DROP;
a11d206d YH	68	}
	69
	70	rcu_read_lock();
1da177e4	71
a11d206d YH	72	idev = __in6_dev_get(skb->dev);
a11d206d YH	73
edf391ff	74	IP6_UPD_PO_STATS_BH(net, idev, IPSTATS_MIB_IN, skb->len);
1da177e4	75
778d80be YH	76	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL \|\|
778d80be YH	77	!idev \|\| unlikely(idev->cnf.disable_ipv6)) {
483a47d2	78	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
71f6f6df	79	goto drop;
1da177e4 LT	80	}
1da177e4 LT	81
6b7fdc3a GC	82	memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
6b7fdc3a GC	83
1da177e4 LT	84	/*
	85	* Store incoming device index. When the packet will
	86	* be queued, we cannot refer to skb->dev anymore.
	87	*
	88	* BTW, when we send a packet for our own local address on a
	89	* non-loopback interface (e.g. ethX), it is being delivered
de3cb747	90	* via the loopback interface (lo) here; skb->dev = loopback_dev.
1da177e4 LT	91	* It, however, should be considered as if it is being
	92	* arrived via the sending interface (ethX), because of the
	93	* nature of scoping architecture. --yoshfuji
	94	*/
adf30907	95	IP6CB(skb)->iif = skb_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex;
1da177e4	96
2889139a	97	if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
1da177e4 LT	98	goto err;
1da177e4 LT	99
0660e03f	100	hdr = ipv6_hdr(skb);
1da177e4 LT	101
	102	if (hdr->version != 6)
	103	goto err;
	104
f630e43a YH	105	/*
	106	* RFC4291 2.5.3
	107	* A packet received on an interface with a destination address
	108	* of loopback must be dropped.
	109	*/
	110	if (!(dev->flags & IFF_LOOPBACK) &&
	111	ipv6_addr_loopback(&hdr->daddr))
	112	goto err;
	113
c457338d BH	114	/*
	115	* RFC4291 2.7
	116	* Multicast addresses must not be used as source addresses in IPv6
	117	* packets or appear in any Routing header.
	118	*/
	119	if (ipv6_addr_is_multicast(&hdr->saddr))
	120	goto err;
	121
b0e380b1	122	skb->transport_header = skb->network_header + sizeof(*hdr);
951dbc8a PM	123	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
951dbc8a PM	124
1da177e4 LT	125	pkt_len = ntohs(hdr->payload_len);
	126
	127	/* pkt_len may be zero if Jumbo payload option is present */
	128	if (pkt_len \|\| hdr->nexthdr != NEXTHDR_HOP) {
60e5c166	129	if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
483a47d2 DL	130	IP6_INC_STATS_BH(net,
483a47d2 DL	131	idev, IPSTATS_MIB_INTRUNCATEDPKTS);
60e5c166 MC	132	goto drop;
60e5c166 MC	133	}
1da177e4	134	if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
483a47d2	135	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
1da177e4 LT	136	goto drop;
1da177e4 LT	137	}
0660e03f	138	hdr = ipv6_hdr(skb);
1da177e4 LT	139	}
	140
	141	if (hdr->nexthdr == NEXTHDR_HOP) {
e5bbef20	142	if (ipv6_parse_hopopts(skb) < 0) {
483a47d2	143	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
a11d206d	144	rcu_read_unlock();
5c91face	145	return NET_RX_DROP;
1da177e4	146	}
1da177e4 LT	147	}
1da177e4 LT	148
a11d206d YH	149	rcu_read_unlock();
a11d206d YH	150
71f9dacd HX	151	/* Must drop socket now because of tproxy. */
	152	skb_orphan(skb);
	153
b2e0b385	154	return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, dev, NULL,
6e23ae2a	155	ip6_rcv_finish);
1da177e4	156	err:
483a47d2	157	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
1da177e4	158	drop:
a11d206d	159	rcu_read_unlock();
1da177e4	160	kfree_skb(skb);
5c91face	161	return NET_RX_DROP;
1da177e4 LT	162	}
	163
	164	/*
	165	* Deliver the packet to the host
	166	*/
	167
	168
ad643a79	169	static int ip6_input_finish(struct sk_buff *skb)
1da177e4	170	{
41135cc8	171	const struct inet6_protocol *ipprot;
1da177e4	172	unsigned int nhoff;
69d6da0b	173	int nexthdr, raw;
1da177e4	174	u8 hash;
a11d206d	175	struct inet6_dev *idev;
adf30907	176	struct net *net = dev_net(skb_dst(skb)->dev);
1da177e4	177
1da177e4 LT	178	/*
	179	* Parse extension headers
	180	*/
	181
1da177e4 LT	182	rcu_read_lock();
1da177e4 LT	183	resubmit:
adf30907	184	idev = ip6_dst_idev(skb_dst(skb));
ea2ae17d	185	if (!pskb_pull(skb, skb_transport_offset(skb)))
1da177e4	186	goto discard;
951dbc8a	187	nhoff = IP6CB(skb)->nhoff;
d56f90a7	188	nexthdr = skb_network_header(skb)[nhoff];
1da177e4	189
69d6da0b	190	raw = raw6_local_deliver(skb, nexthdr);
1da177e4 LT	191
	192	hash = nexthdr & (MAX_INET_PROTOS - 1);
	193	if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {
	194	int ret;
1ab1457c	195
1da177e4	196	if (ipprot->flags & INET6_PROTO_FINAL) {
b71d1d42	197	const struct ipv6hdr *hdr;
1da177e4	198
9fb9cbb1 YK	199	/* Free reference early: we don't need it any more,
	200	and it may hold ip_conntrack module loaded
	201	indefinitely. */
	202	nf_reset(skb);
	203
d56f90a7	204	skb_postpull_rcsum(skb, skb_network_header(skb),
cfe1fc77	205	skb_network_header_len(skb));
0660e03f	206	hdr = ipv6_hdr(skb);
1da177e4 LT	207	if (ipv6_addr_is_multicast(&hdr->daddr) &&
	208	!ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
	209	&hdr->saddr) &&
	210	!ipv6_is_mld(skb, nexthdr))
	211	goto discard;
	212	}
	213	if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
1ab1457c	214	!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1da177e4	215	goto discard;
1ab1457c	216
e5bbef20	217	ret = ipprot->handler(skb);
1da177e4 LT	218	if (ret > 0)
	219	goto resubmit;
	220	else if (ret == 0)
483a47d2	221	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
1da177e4	222	} else {
69d6da0b	223	if (!raw) {
1da177e4	224	if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
483a47d2 DL	225	IP6_INC_STATS_BH(net, idev,
483a47d2 DL	226	IPSTATS_MIB_INUNKNOWNPROTOS);
fad87aca	227	icmpv6_send(skb, ICMPV6_PARAMPROB,
3ffe533c	228	ICMPV6_UNK_NEXTHDR, nhoff);
1da177e4	229	}
fad87aca	230	} else
483a47d2	231	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
fad87aca	232	kfree_skb(skb);
1da177e4 LT	233	}
	234	rcu_read_unlock();
	235	return 0;
	236
	237	discard:
483a47d2	238	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
1da177e4 LT	239	rcu_read_unlock();
	240	kfree_skb(skb);
	241	return 0;
	242	}
	243
	244
	245	int ip6_input(struct sk_buff *skb)
	246	{
b2e0b385	247	return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN, skb, skb->dev, NULL,
6e23ae2a	248	ip6_input_finish);
1da177e4 LT	249	}
	250
	251	int ip6_mc_input(struct sk_buff *skb)
	252	{
b71d1d42	253	const struct ipv6hdr *hdr;
1da177e4 LT	254	int deliver;
1da177e4 LT	255
adf30907 ED	256	IP6_UPD_PO_STATS_BH(dev_net(skb_dst(skb)->dev),
adf30907 ED	257	ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST,
edf391ff	258	skb->len);
1da177e4	259
0660e03f	260	hdr = ipv6_hdr(skb);
4c7966b8	261	deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
1da177e4	262
7bc570c8	263	#ifdef CONFIG_IPV6_MROUTE
1da177e4	264	/*
7bc570c8	265	* IPv6 multicast router mode is now supported ;)
1da177e4	266	*/
53b7997f	267	if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
1d6e55f1	268	!(ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) &&
7bc570c8 YH	269	likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
	270	/*
	271	* Okay, we try to forward - split and duplicate
	272	* packets.
	273	*/
	274	struct sk_buff *skb2;
	275	struct inet6_skb_parm *opt = IP6CB(skb);
	276
	277	/* Check for MLD */
	278	if (unlikely(opt->ra)) {
	279	/* Check if this is a mld message */
	280	u8 *ptr = skb_network_header(skb) + opt->ra;
	281	struct icmp6hdr *icmp6;
	282	u8 nexthdr = hdr->nexthdr;
75f2811c	283	__be16 frag_off;
7bc570c8 YH	284	int offset;
	285
	286	/* Check if the value of Router Alert
	287	* is for MLD (0x0000).
	288	*/
	289	if ((ptr[2] \| ptr[3]) == 0) {
aba6096b YH	290	deliver = 0;
aba6096b YH	291
7bc570c8 YH	292	if (!ipv6_ext_hdr(nexthdr)) {
7bc570c8 YH	293	/* BUG */
aba6096b	294	goto out;
7bc570c8 YH	295	}
7bc570c8 YH	296	offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
75f2811c	297	&nexthdr, &frag_off);
7bc570c8	298	if (offset < 0)
aba6096b	299	goto out;
7bc570c8 YH	300
7bc570c8 YH	301	if (nexthdr != IPPROTO_ICMPV6)
aba6096b	302	goto out;
7bc570c8 YH	303
	304	if (!pskb_may_pull(skb, (skb_network_header(skb) +
	305	offset + 1 - skb->data)))
aba6096b	306	goto out;
7bc570c8 YH	307
	308	icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
	309
	310	switch (icmp6->icmp6_type) {
	311	case ICMPV6_MGM_QUERY:
	312	case ICMPV6_MGM_REPORT:
	313	case ICMPV6_MGM_REDUCTION:
	314	case ICMPV6_MLD2_REPORT:
aba6096b	315	deliver = 1;
7bc570c8	316	break;
7bc570c8	317	}
7bc570c8 YH	318	goto out;
	319	}
	320	/* unknown RA - process it normally */
	321	}
1da177e4	322
7bc570c8 YH	323	if (deliver)
	324	skb2 = skb_clone(skb, GFP_ATOMIC);
	325	else {
	326	skb2 = skb;
	327	skb = NULL;
	328	}
1ab1457c	329
7bc570c8	330	if (skb2) {
7bc570c8	331	ip6_mr_input(skb2);
1da177e4 LT	332	}
1da177e4 LT	333	}
7bc570c8	334	out:
aba6096b YH	335	#endif
aba6096b YH	336	if (likely(deliver))
1da177e4	337	ip6_input(skb);
aba6096b YH	338	else {
	339	/* discard */
	340	kfree_skb(skb);
1da177e4	341	}
1da177e4 LT	342
	343	return 0;
	344	}