[deliverable/linux.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>
#include <net/inet_ecn.h>

int ip6_rcv_finish(struct sock *sk, struct sk_buff *skb)
{
	if (sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) {
		const struct inet6_protocol *ipprot;

		ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]);
		if (ipprot && ipprot->early_demux)
			ipprot->early_demux(skb);
	}
	if (!skb_dst(skb))
		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;

	IP6_ADD_STATS_BH(dev_net(dev), idev,
			 IPSTATS_MIB_NOECTPKTS +
				(ipv6_get_dsfield(hdr) & INET_ECN_MASK),
			 max_t(unsigned short, 1, skb_shinfo(skb)->gso_segs));
	/*
	 * 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 Errata ID: 3480
	 * Interface-Local scope spans only a single interface on a
	 * node and is useful only for loopback transmission of
	 * multicast.  Packets with interface-local scope received
	 * from another node must be discarded.
	 */
	if (!(skb->pkt_type == PACKET_LOOPBACK ||
	      dev->flags & IFF_LOOPBACK) &&
	    ipv6_addr_is_multicast(&hdr->daddr) &&
	    IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 1)
		goto err;

	/* RFC4291 2.7
	 * Nodes must not originate a packet to a multicast address whose scope
	 * field contains the reserved value 0; if such a packet is received, it
	 * must be silently dropped.
	 */
	if (ipv6_addr_is_multicast(&hdr->daddr) &&
	    IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 0)
		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, NULL, 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 sock *sk, struct sk_buff *skb)
{
	struct net *net = dev_net(skb_dst(skb)->dev);
	const struct inet6_protocol *ipprot;
	struct inet6_dev *idev;
	unsigned int nhoff;
	int nexthdr;
	bool raw;

	/*
	 *	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);
	ipprot = rcu_dereference(inet6_protos[nexthdr]);
	if (ipprot) {
		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, skb_network_header_len(skb)))
				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);
			}
			kfree_skb(skb);
		} else {
			IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
			consume_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, NULL, skb,
		       skb->dev, NULL,
		       ip6_input_finish);
}

int ip6_mc_input(struct sk_buff *skb)
{
	const struct ipv6hdr *hdr;
	bool 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_LOOPBACK|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->flags & IP6SKB_ROUTERALERT)) {
			/* Check if this is a mld message */
			u8 nexthdr = hdr->nexthdr;
			__be16 frag_off;
			int offset;

			/* Check if the value of Router Alert
			 * is for MLD (0x0000).
			 */
			if (opt->ra == htons(IPV6_OPT_ROUTERALERT_MLD)) {
				deliver = false;

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

				if (ipv6_is_mld(skb, nexthdr, offset))
					deliver = true;

				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	*
67ba4152 IM	18	* Mitsuru KANDA @USAGI and
67ba4152 IM	19	* YOSHIFUJI Hideaki @USAGI: Remove ipv6_parse_exthdrs().
1da177e4 LT	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>
1f07d03e	47	#include <net/inet_ecn.h>
1da177e4	48
7026b1dd	49	int ip6_rcv_finish(struct sock sk, struct sk_buff skb)
1da177e4	50	{
a452ce34	51	if (sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) {
c7109986 ED	52	const struct inet6_protocol *ipprot;
c7109986 ED	53
c7109986 ED	54	ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]);
	55	if (ipprot && ipprot->early_demux)
	56	ipprot->early_demux(skb);
c7109986 ED	57	}
c7109986 ED	58	if (!skb_dst(skb))
1da177e4 LT	59	ip6_route_input(skb);
	60
	61	return dst_input(skb);
	62	}
	63
f2ccd8fa	64	int ipv6_rcv(struct sk_buff skb, struct net_device dev, struct packet_type pt, struct net_device orig_dev)
1da177e4	65	{
b71d1d42	66	const struct ipv6hdr *hdr;
67ba4152	67	u32 pkt_len;
a11d206d	68	struct inet6_dev *idev;
483a47d2	69	struct net *net = dev_net(skb->dev);
1da177e4	70
a11d206d YH	71	if (skb->pkt_type == PACKET_OTHERHOST) {
a11d206d YH	72	kfree_skb(skb);
5c91face	73	return NET_RX_DROP;
a11d206d YH	74	}
	75
	76	rcu_read_lock();
1da177e4	77
a11d206d YH	78	idev = __in6_dev_get(skb->dev);
a11d206d YH	79
edf391ff	80	IP6_UPD_PO_STATS_BH(net, idev, IPSTATS_MIB_IN, skb->len);
1da177e4	81
778d80be YH	82	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL \|\|
778d80be YH	83	!idev \|\| unlikely(idev->cnf.disable_ipv6)) {
483a47d2	84	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
71f6f6df	85	goto drop;
1da177e4 LT	86	}
1da177e4 LT	87
6b7fdc3a GC	88	memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
6b7fdc3a GC	89
1da177e4 LT	90	/*
	91	* Store incoming device index. When the packet will
	92	* be queued, we cannot refer to skb->dev anymore.
	93	*
	94	* BTW, when we send a packet for our own local address on a
	95	* non-loopback interface (e.g. ethX), it is being delivered
de3cb747	96	* via the loopback interface (lo) here; skb->dev = loopback_dev.
1da177e4 LT	97	* It, however, should be considered as if it is being
	98	* arrived via the sending interface (ethX), because of the
	99	* nature of scoping architecture. --yoshfuji
	100	*/
adf30907	101	IP6CB(skb)->iif = skb_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex;
1da177e4	102
2889139a	103	if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
1da177e4 LT	104	goto err;
1da177e4 LT	105
0660e03f	106	hdr = ipv6_hdr(skb);
1da177e4 LT	107
	108	if (hdr->version != 6)
	109	goto err;
	110
1f07d03e ED	111	IP6_ADD_STATS_BH(dev_net(dev), idev,
	112	IPSTATS_MIB_NOECTPKTS +
	113	(ipv6_get_dsfield(hdr) & INET_ECN_MASK),
	114	max_t(unsigned short, 1, skb_shinfo(skb)->gso_segs));
f630e43a YH	115	/*
	116	* RFC4291 2.5.3
	117	* A packet received on an interface with a destination address
	118	* of loopback must be dropped.
	119	*/
	120	if (!(dev->flags & IFF_LOOPBACK) &&
	121	ipv6_addr_loopback(&hdr->daddr))
	122	goto err;
	123
1c4a154e HFS	124	/* RFC4291 Errata ID: 3480
	125	* Interface-Local scope spans only a single interface on a
	126	* node and is useful only for loopback transmission of
	127	* multicast. Packets with interface-local scope received
	128	* from another node must be discarded.
	129	*/
	130	if (!(skb->pkt_type == PACKET_LOOPBACK \|\|
	131	dev->flags & IFF_LOOPBACK) &&
	132	ipv6_addr_is_multicast(&hdr->daddr) &&
	133	IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 1)
	134	goto err;
	135
20314092 HFS	136	/* RFC4291 2.7
	137	* Nodes must not originate a packet to a multicast address whose scope
	138	* field contains the reserved value 0; if such a packet is received, it
	139	* must be silently dropped.
	140	*/
	141	if (ipv6_addr_is_multicast(&hdr->daddr) &&
	142	IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 0)
	143	goto err;
	144
c457338d BH	145	/*
	146	* RFC4291 2.7
	147	* Multicast addresses must not be used as source addresses in IPv6
	148	* packets or appear in any Routing header.
	149	*/
	150	if (ipv6_addr_is_multicast(&hdr->saddr))
	151	goto err;
	152
b0e380b1	153	skb->transport_header = skb->network_header + sizeof(*hdr);
951dbc8a PM	154	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
951dbc8a PM	155
1da177e4 LT	156	pkt_len = ntohs(hdr->payload_len);
	157
	158	/* pkt_len may be zero if Jumbo payload option is present */
	159	if (pkt_len \|\| hdr->nexthdr != NEXTHDR_HOP) {
60e5c166	160	if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
483a47d2 DL	161	IP6_INC_STATS_BH(net,
483a47d2 DL	162	idev, IPSTATS_MIB_INTRUNCATEDPKTS);
60e5c166 MC	163	goto drop;
60e5c166 MC	164	}
1da177e4	165	if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
483a47d2	166	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
1da177e4 LT	167	goto drop;
1da177e4 LT	168	}
0660e03f	169	hdr = ipv6_hdr(skb);
1da177e4 LT	170	}
	171
	172	if (hdr->nexthdr == NEXTHDR_HOP) {
e5bbef20	173	if (ipv6_parse_hopopts(skb) < 0) {
483a47d2	174	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
a11d206d	175	rcu_read_unlock();
5c91face	176	return NET_RX_DROP;
1da177e4	177	}
1da177e4 LT	178	}
1da177e4 LT	179
a11d206d YH	180	rcu_read_unlock();
a11d206d YH	181
71f9dacd HX	182	/* Must drop socket now because of tproxy. */
	183	skb_orphan(skb);
	184
7026b1dd DM	185	return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING, NULL, skb,
7026b1dd DM	186	dev, NULL,
6e23ae2a	187	ip6_rcv_finish);
1da177e4	188	err:
483a47d2	189	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INHDRERRORS);
1da177e4	190	drop:
a11d206d	191	rcu_read_unlock();
1da177e4	192	kfree_skb(skb);
5c91face	193	return NET_RX_DROP;
1da177e4 LT	194	}
	195
	196	/*
	197	* Deliver the packet to the host
	198	*/
	199
	200
7026b1dd	201	static int ip6_input_finish(struct sock sk, struct sk_buff skb)
1da177e4	202	{
f9242b6b	203	struct net *net = dev_net(skb_dst(skb)->dev);
41135cc8	204	const struct inet6_protocol *ipprot;
f9242b6b	205	struct inet6_dev *idev;
1da177e4	206	unsigned int nhoff;
a50feda5 ED	207	int nexthdr;
a50feda5 ED	208	bool raw;
1da177e4	209
1da177e4 LT	210	/*
	211	* Parse extension headers
	212	*/
	213
1da177e4	214	rcu_read_lock();
1b0ccfe5	215	resubmit:
adf30907	216	idev = ip6_dst_idev(skb_dst(skb));
ea2ae17d	217	if (!pskb_pull(skb, skb_transport_offset(skb)))
1da177e4	218	goto discard;
951dbc8a	219	nhoff = IP6CB(skb)->nhoff;
d56f90a7	220	nexthdr = skb_network_header(skb)[nhoff];
1da177e4	221
69d6da0b	222	raw = raw6_local_deliver(skb, nexthdr);
e5d08d71	223	ipprot = rcu_dereference(inet6_protos[nexthdr]);
53b24b8f	224	if (ipprot) {
1da177e4	225	int ret;
1ab1457c	226
1da177e4	227	if (ipprot->flags & INET6_PROTO_FINAL) {
b71d1d42	228	const struct ipv6hdr *hdr;
1da177e4	229
9fb9cbb1 YK	230	/* Free reference early: we don't need it any more,
	231	and it may hold ip_conntrack module loaded
	232	indefinitely. */
	233	nf_reset(skb);
	234
d56f90a7	235	skb_postpull_rcsum(skb, skb_network_header(skb),
cfe1fc77	236	skb_network_header_len(skb));
0660e03f	237	hdr = ipv6_hdr(skb);
1da177e4 LT	238	if (ipv6_addr_is_multicast(&hdr->daddr) &&
	239	!ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
	240	&hdr->saddr) &&
daad1512	241	!ipv6_is_mld(skb, nexthdr, skb_network_header_len(skb)))
1da177e4 LT	242	goto discard;
	243	}
	244	if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
1ab1457c	245	!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1da177e4	246	goto discard;
1ab1457c	247
e5bbef20	248	ret = ipprot->handler(skb);
1b0ccfe5	249	if (ret > 0)
1da177e4	250	goto resubmit;
1b0ccfe5	251	else if (ret == 0)
483a47d2	252	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
1da177e4	253	} else {
69d6da0b	254	if (!raw) {
1da177e4	255	if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
483a47d2 DL	256	IP6_INC_STATS_BH(net, idev,
483a47d2 DL	257	IPSTATS_MIB_INUNKNOWNPROTOS);
fad87aca	258	icmpv6_send(skb, ICMPV6_PARAMPROB,
3ffe533c	259	ICMPV6_UNK_NEXTHDR, nhoff);
1da177e4	260	}
d8c6f4b9 NH	261	kfree_skb(skb);
d8c6f4b9 NH	262	} else {
483a47d2	263	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDELIVERS);
d8c6f4b9 NH	264	consume_skb(skb);
d8c6f4b9 NH	265	}
1da177e4 LT	266	}
	267	rcu_read_unlock();
	268	return 0;
	269
	270	discard:
483a47d2	271	IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_INDISCARDS);
1da177e4 LT	272	rcu_read_unlock();
	273	kfree_skb(skb);
	274	return 0;
	275	}
	276
	277
	278	int ip6_input(struct sk_buff *skb)
	279	{
7026b1dd DM	280	return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN, NULL, skb,
7026b1dd DM	281	skb->dev, NULL,
6e23ae2a	282	ip6_input_finish);
1da177e4 LT	283	}
	284
	285	int ip6_mc_input(struct sk_buff *skb)
	286	{
b71d1d42	287	const struct ipv6hdr *hdr;
a50feda5	288	bool deliver;
1da177e4	289
adf30907 ED	290	IP6_UPD_PO_STATS_BH(dev_net(skb_dst(skb)->dev),
adf30907 ED	291	ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST,
edf391ff	292	skb->len);
1da177e4	293
0660e03f	294	hdr = ipv6_hdr(skb);
4c7966b8	295	deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
1da177e4	296
7bc570c8	297	#ifdef CONFIG_IPV6_MROUTE
1da177e4	298	/*
7bc570c8	299	* IPv6 multicast router mode is now supported ;)
1da177e4	300	*/
53b7997f	301	if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
ddf64354 HFS	302	!(ipv6_addr_type(&hdr->daddr) &
ddf64354 HFS	303	(IPV6_ADDR_LOOPBACK\|IPV6_ADDR_LINKLOCAL)) &&
7bc570c8 YH	304	likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
	305	/*
	306	* Okay, we try to forward - split and duplicate
	307	* packets.
	308	*/
	309	struct sk_buff *skb2;
	310	struct inet6_skb_parm *opt = IP6CB(skb);
	311
	312	/* Check for MLD */
dd3332bf	313	if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
7bc570c8	314	/* Check if this is a mld message */
7bc570c8	315	u8 nexthdr = hdr->nexthdr;
75f2811c	316	__be16 frag_off;
7bc570c8 YH	317	int offset;
	318
	319	/* Check if the value of Router Alert
	320	* is for MLD (0x0000).
	321	*/
dd3332bf	322	if (opt->ra == htons(IPV6_OPT_ROUTERALERT_MLD)) {
a50feda5	323	deliver = false;
aba6096b	324
7bc570c8 YH	325	if (!ipv6_ext_hdr(nexthdr)) {
7bc570c8 YH	326	/* BUG */
aba6096b	327	goto out;
7bc570c8 YH	328	}
7bc570c8 YH	329	offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
75f2811c	330	&nexthdr, &frag_off);
7bc570c8	331	if (offset < 0)
aba6096b	332	goto out;
7bc570c8	333
4c938d22 A	334	if (ipv6_is_mld(skb, nexthdr, offset))
4c938d22 A	335	deliver = true;
7bc570c8	336
4c938d22	337	goto out;
7bc570c8 YH	338	}
	339	/* unknown RA - process it normally */
	340	}
1da177e4	341
7bc570c8 YH	342	if (deliver)
	343	skb2 = skb_clone(skb, GFP_ATOMIC);
	344	else {
	345	skb2 = skb;
	346	skb = NULL;
	347	}
1ab1457c	348
7bc570c8	349	if (skb2) {
7bc570c8	350	ip6_mr_input(skb2);
1da177e4 LT	351	}
1da177e4 LT	352	}
7bc570c8	353	out:
aba6096b YH	354	#endif
aba6096b YH	355	if (likely(deliver))
1da177e4	356	ip6_input(skb);
aba6096b YH	357	else {
	358	/* discard */
	359	kfree_skb(skb);
1da177e4	360	}
1da177e4 LT	361
	362	return 0;
	363	}