[linux-2.6-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>
#include <net/inet_ecn.h>
#include <net/dst_metadata.h>

int ip6_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
{
	/* if ingress device is enslaved to an L3 master device pass the
	 * skb to its handler for processing
	 */
	skb = l3mdev_ip6_rcv(skb);
	if (!skb)
		return NET_RX_SUCCESS;

	if (net->ipv4.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_valid_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(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(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_valid_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(net, 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;

	/* If enabled, drop unicast packets that were encapsulated in link-layer
	 * multicast or broadcast to protected against the so-called "hole-196"
	 * attack in 802.11 wireless.
	 */
	if (!ipv6_addr_is_multicast(&hdr->daddr) &&
	    (skb->pkt_type == PACKET_BROADCAST ||
	     skb->pkt_type == PACKET_MULTICAST) &&
	    idev->cnf.drop_unicast_in_l2_multicast)
		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(net,
					idev, IPSTATS_MIB_INTRUNCATEDPKTS);
			goto drop;
		}
		if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
			__IP6_INC_STATS(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(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,
		       net, NULL, skb, dev, NULL,
		       ip6_rcv_finish);
err:
	__IP6_INC_STATS(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 net *net, struct sock *sk, struct sk_buff *skb)
{
	const struct inet6_protocol *ipprot;
	struct inet6_dev *idev;
	unsigned int nhoff;
	int nexthdr;
	bool raw;
	bool have_final = false;

	/*
	 *	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];

resubmit_final:
	raw = raw6_local_deliver(skb, nexthdr);
	ipprot = rcu_dereference(inet6_protos[nexthdr]);
	if (ipprot) {
		int ret;

		if (have_final) {
			if (!(ipprot->flags & INET6_PROTO_FINAL)) {
				/* Once we've seen a final protocol don't
				 * allow encapsulation on any non-final
				 * ones. This allows foo in UDP encapsulation
				 * to work.
				 */
				goto discard;
			}
		} else if (ipprot->flags & INET6_PROTO_FINAL) {
			const struct ipv6hdr *hdr;

			/* Only do this once for first final protocol */
			have_final = true;

			/* 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) {
			if (ipprot->flags & INET6_PROTO_FINAL) {
				/* Not an extension header, most likely UDP
				 * encapsulation. Use return value as nexthdr
				 * protocol not nhoff (which presumably is
				 * not set by handler).
				 */
				nexthdr = ret;
				goto resubmit_final;
			} else {
				goto resubmit;
			}
		} else if (ret == 0) {
			__IP6_INC_STATS(net, idev, IPSTATS_MIB_INDELIVERS);
		}
	} else {
		if (!raw) {
			if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
				__IP6_INC_STATS(net, idev,
						IPSTATS_MIB_INUNKNOWNPROTOS);
				icmpv6_send(skb, ICMPV6_PARAMPROB,
					    ICMPV6_UNK_NEXTHDR, nhoff);
			}
			kfree_skb(skb);
		} else {
			__IP6_INC_STATS(net, idev, IPSTATS_MIB_INDELIVERS);
			consume_skb(skb);
		}
	}
	rcu_read_unlock();
	return 0;

discard:
	__IP6_INC_STATS(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,
		       dev_net(skb->dev), NULL, skb, skb->dev, NULL,
		       ip6_input_finish);
}
EXPORT_SYMBOL_GPL(ip6_input);

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

	__IP6_UPD_PO_STATS(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>
48fb6b55	48	#include <net/dst_metadata.h>
1da177e4	49
0c4b51f0	50	int ip6_rcv_finish(struct net net, struct sock sk, struct sk_buff *skb)
1da177e4	51	{
74b20582 DA	52	/* if ingress device is enslaved to an L3 master device pass the
	53	* skb to its handler for processing
	54	*/
	55	skb = l3mdev_ip6_rcv(skb);
	56	if (!skb)
	57	return NET_RX_SUCCESS;
	58
e21145a9	59	if (net->ipv4.sysctl_ip_early_demux && !skb_dst(skb) && skb->sk == NULL) {
c7109986 ED	60	const struct inet6_protocol *ipprot;
c7109986 ED	61
c7109986 ED	62	ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]);
	63	if (ipprot && ipprot->early_demux)
	64	ipprot->early_demux(skb);
c7109986	65	}
48fb6b55	66	if (!skb_valid_dst(skb))
1da177e4 LT	67	ip6_route_input(skb);
	68
	69	return dst_input(skb);
	70	}
	71
f2ccd8fa	72	int ipv6_rcv(struct sk_buff skb, struct net_device dev, struct packet_type pt, struct net_device orig_dev)
1da177e4	73	{
b71d1d42	74	const struct ipv6hdr *hdr;
67ba4152	75	u32 pkt_len;
a11d206d	76	struct inet6_dev *idev;
483a47d2	77	struct net *net = dev_net(skb->dev);
1da177e4	78
a11d206d YH	79	if (skb->pkt_type == PACKET_OTHERHOST) {
a11d206d YH	80	kfree_skb(skb);
5c91face	81	return NET_RX_DROP;
a11d206d YH	82	}
	83
	84	rcu_read_lock();
1da177e4	85
a11d206d YH	86	idev = __in6_dev_get(skb->dev);
a11d206d YH	87
c2005eb0	88	__IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_IN, skb->len);
1da177e4	89
778d80be YH	90	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL \|\|
778d80be YH	91	!idev \|\| unlikely(idev->cnf.disable_ipv6)) {
1d015503	92	__IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
71f6f6df	93	goto drop;
1da177e4 LT	94	}
1da177e4 LT	95
6b7fdc3a GC	96	memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
6b7fdc3a GC	97
1da177e4 LT	98	/*
	99	* Store incoming device index. When the packet will
	100	* be queued, we cannot refer to skb->dev anymore.
	101	*
	102	* BTW, when we send a packet for our own local address on a
	103	* non-loopback interface (e.g. ethX), it is being delivered
de3cb747	104	* via the loopback interface (lo) here; skb->dev = loopback_dev.
1da177e4 LT	105	* It, however, should be considered as if it is being
	106	* arrived via the sending interface (ethX), because of the
	107	* nature of scoping architecture. --yoshfuji
	108	*/
48fb6b55	109	IP6CB(skb)->iif = skb_valid_dst(skb) ? ip6_dst_idev(skb_dst(skb))->dev->ifindex : dev->ifindex;
1da177e4	110
2889139a	111	if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
1da177e4 LT	112	goto err;
1da177e4 LT	113
0660e03f	114	hdr = ipv6_hdr(skb);
1da177e4 LT	115
	116	if (hdr->version != 6)
	117	goto err;
	118
1d015503 ED	119	__IP6_ADD_STATS(net, idev,
1d015503 ED	120	IPSTATS_MIB_NOECTPKTS +
1f07d03e	121	(ipv6_get_dsfield(hdr) & INET_ECN_MASK),
1d015503	122	max_t(unsigned short, 1, skb_shinfo(skb)->gso_segs));
f630e43a YH	123	/*
	124	* RFC4291 2.5.3
	125	* A packet received on an interface with a destination address
	126	* of loopback must be dropped.
	127	*/
	128	if (!(dev->flags & IFF_LOOPBACK) &&
	129	ipv6_addr_loopback(&hdr->daddr))
	130	goto err;
	131
1c4a154e HFS	132	/* RFC4291 Errata ID: 3480
	133	* Interface-Local scope spans only a single interface on a
	134	* node and is useful only for loopback transmission of
	135	* multicast. Packets with interface-local scope received
	136	* from another node must be discarded.
	137	*/
	138	if (!(skb->pkt_type == PACKET_LOOPBACK \|\|
	139	dev->flags & IFF_LOOPBACK) &&
	140	ipv6_addr_is_multicast(&hdr->daddr) &&
	141	IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 1)
	142	goto err;
	143
abbc3043 JB	144	/* If enabled, drop unicast packets that were encapsulated in link-layer
	145	* multicast or broadcast to protected against the so-called "hole-196"
	146	* attack in 802.11 wireless.
	147	*/
	148	if (!ipv6_addr_is_multicast(&hdr->daddr) &&
	149	(skb->pkt_type == PACKET_BROADCAST \|\|
	150	skb->pkt_type == PACKET_MULTICAST) &&
	151	idev->cnf.drop_unicast_in_l2_multicast)
	152	goto err;
	153
20314092 HFS	154	/* RFC4291 2.7
	155	* Nodes must not originate a packet to a multicast address whose scope
	156	* field contains the reserved value 0; if such a packet is received, it
	157	* must be silently dropped.
	158	*/
	159	if (ipv6_addr_is_multicast(&hdr->daddr) &&
	160	IPV6_ADDR_MC_SCOPE(&hdr->daddr) == 0)
	161	goto err;
	162
c457338d BH	163	/*
	164	* RFC4291 2.7
	165	* Multicast addresses must not be used as source addresses in IPv6
	166	* packets or appear in any Routing header.
	167	*/
	168	if (ipv6_addr_is_multicast(&hdr->saddr))
	169	goto err;
	170
b0e380b1	171	skb->transport_header = skb->network_header + sizeof(*hdr);
951dbc8a PM	172	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
951dbc8a PM	173
1da177e4 LT	174	pkt_len = ntohs(hdr->payload_len);
	175
	176	/* pkt_len may be zero if Jumbo payload option is present */
	177	if (pkt_len \|\| hdr->nexthdr != NEXTHDR_HOP) {
60e5c166	178	if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
1d015503 ED	179	__IP6_INC_STATS(net,
1d015503 ED	180	idev, IPSTATS_MIB_INTRUNCATEDPKTS);
60e5c166 MC	181	goto drop;
60e5c166 MC	182	}
1da177e4	183	if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
1d015503	184	__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
1da177e4 LT	185	goto drop;
1da177e4 LT	186	}
0660e03f	187	hdr = ipv6_hdr(skb);
1da177e4 LT	188	}
	189
	190	if (hdr->nexthdr == NEXTHDR_HOP) {
e5bbef20	191	if (ipv6_parse_hopopts(skb) < 0) {
1d015503	192	__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
a11d206d	193	rcu_read_unlock();
5c91face	194	return NET_RX_DROP;
1da177e4	195	}
1da177e4 LT	196	}
1da177e4 LT	197
a11d206d YH	198	rcu_read_unlock();
a11d206d YH	199
71f9dacd HX	200	/* Must drop socket now because of tproxy. */
	201	skb_orphan(skb);
	202
29a26a56 EB	203	return NF_HOOK(NFPROTO_IPV6, NF_INET_PRE_ROUTING,
29a26a56 EB	204	net, NULL, skb, dev, NULL,
6e23ae2a	205	ip6_rcv_finish);
1da177e4	206	err:
1d015503	207	__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
1da177e4	208	drop:
a11d206d	209	rcu_read_unlock();
1da177e4	210	kfree_skb(skb);
5c91face	211	return NET_RX_DROP;
1da177e4 LT	212	}
	213
	214	/*
	215	* Deliver the packet to the host
	216	*/
	217
	218
0c4b51f0	219	static int ip6_input_finish(struct net net, struct sock sk, struct sk_buff *skb)
1da177e4	220	{
41135cc8	221	const struct inet6_protocol *ipprot;
f9242b6b	222	struct inet6_dev *idev;
1da177e4	223	unsigned int nhoff;
a50feda5 ED	224	int nexthdr;
a50feda5 ED	225	bool raw;
1da44f9c	226	bool have_final = false;
1da177e4	227
1da177e4 LT	228	/*
	229	* Parse extension headers
	230	*/
	231
1da177e4	232	rcu_read_lock();
1b0ccfe5	233	resubmit:
adf30907	234	idev = ip6_dst_idev(skb_dst(skb));
ea2ae17d	235	if (!pskb_pull(skb, skb_transport_offset(skb)))
1da177e4	236	goto discard;
951dbc8a	237	nhoff = IP6CB(skb)->nhoff;
d56f90a7	238	nexthdr = skb_network_header(skb)[nhoff];
1da177e4	239
4c64242a	240	resubmit_final:
69d6da0b	241	raw = raw6_local_deliver(skb, nexthdr);
e5d08d71	242	ipprot = rcu_dereference(inet6_protos[nexthdr]);
53b24b8f	243	if (ipprot) {
1da177e4	244	int ret;
1ab1457c	245
1da44f9c TH	246	if (have_final) {
	247	if (!(ipprot->flags & INET6_PROTO_FINAL)) {
	248	/* Once we've seen a final protocol don't
	249	* allow encapsulation on any non-final
	250	* ones. This allows foo in UDP encapsulation
	251	* to work.
	252	*/
	253	goto discard;
	254	}
	255	} else if (ipprot->flags & INET6_PROTO_FINAL) {
b71d1d42	256	const struct ipv6hdr *hdr;
1da177e4	257
1da44f9c TH	258	/* Only do this once for first final protocol */
	259	have_final = true;
	260
9fb9cbb1 YK	261	/* Free reference early: we don't need it any more,
	262	and it may hold ip_conntrack module loaded
	263	indefinitely. */
	264	nf_reset(skb);
	265
d56f90a7	266	skb_postpull_rcsum(skb, skb_network_header(skb),
cfe1fc77	267	skb_network_header_len(skb));
0660e03f	268	hdr = ipv6_hdr(skb);
1da177e4 LT	269	if (ipv6_addr_is_multicast(&hdr->daddr) &&
	270	!ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
	271	&hdr->saddr) &&
daad1512	272	!ipv6_is_mld(skb, nexthdr, skb_network_header_len(skb)))
1da177e4 LT	273	goto discard;
	274	}
	275	if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
1ab1457c	276	!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1da177e4	277	goto discard;
1ab1457c	278
e5bbef20	279	ret = ipprot->handler(skb);
4c64242a TH	280	if (ret > 0) {
	281	if (ipprot->flags & INET6_PROTO_FINAL) {
	282	/* Not an extension header, most likely UDP
	283	* encapsulation. Use return value as nexthdr
	284	* protocol not nhoff (which presumably is
	285	* not set by handler).
	286	*/
	287	nexthdr = ret;
	288	goto resubmit_final;
	289	} else {
	290	goto resubmit;
	291	}
	292	} else if (ret == 0) {
1d015503	293	__IP6_INC_STATS(net, idev, IPSTATS_MIB_INDELIVERS);
4c64242a	294	}
1da177e4	295	} else {
69d6da0b	296	if (!raw) {
1da177e4	297	if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
1d015503 ED	298	__IP6_INC_STATS(net, idev,
1d015503 ED	299	IPSTATS_MIB_INUNKNOWNPROTOS);
fad87aca	300	icmpv6_send(skb, ICMPV6_PARAMPROB,
3ffe533c	301	ICMPV6_UNK_NEXTHDR, nhoff);
1da177e4	302	}
d8c6f4b9 NH	303	kfree_skb(skb);
d8c6f4b9 NH	304	} else {
1d015503	305	__IP6_INC_STATS(net, idev, IPSTATS_MIB_INDELIVERS);
d8c6f4b9 NH	306	consume_skb(skb);
d8c6f4b9 NH	307	}
1da177e4 LT	308	}
	309	rcu_read_unlock();
	310	return 0;
	311
	312	discard:
1d015503	313	__IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS);
1da177e4 LT	314	rcu_read_unlock();
	315	kfree_skb(skb);
	316	return 0;
	317	}
	318
	319
	320	int ip6_input(struct sk_buff *skb)
	321	{
29a26a56 EB	322	return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_IN,
29a26a56 EB	323	dev_net(skb->dev), NULL, skb, skb->dev, NULL,
6e23ae2a	324	ip6_input_finish);
1da177e4	325	}
b4869aa2	326	EXPORT_SYMBOL_GPL(ip6_input);
1da177e4 LT	327
	328	int ip6_mc_input(struct sk_buff *skb)
	329	{
b71d1d42	330	const struct ipv6hdr *hdr;
a50feda5	331	bool deliver;
1da177e4	332
c2005eb0	333	__IP6_UPD_PO_STATS(dev_net(skb_dst(skb)->dev),
adf30907	334	ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_INMCAST,
edf391ff	335	skb->len);
1da177e4	336
0660e03f	337	hdr = ipv6_hdr(skb);
4c7966b8	338	deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
1da177e4	339
7bc570c8	340	#ifdef CONFIG_IPV6_MROUTE
1da177e4	341	/*
7bc570c8	342	* IPv6 multicast router mode is now supported ;)
1da177e4	343	*/
53b7997f	344	if (dev_net(skb->dev)->ipv6.devconf_all->mc_forwarding &&
ddf64354 HFS	345	!(ipv6_addr_type(&hdr->daddr) &
ddf64354 HFS	346	(IPV6_ADDR_LOOPBACK\|IPV6_ADDR_LINKLOCAL)) &&
7bc570c8 YH	347	likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
	348	/*
	349	* Okay, we try to forward - split and duplicate
	350	* packets.
	351	*/
	352	struct sk_buff *skb2;
	353	struct inet6_skb_parm *opt = IP6CB(skb);
	354
	355	/* Check for MLD */
dd3332bf	356	if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) {
7bc570c8	357	/* Check if this is a mld message */
7bc570c8	358	u8 nexthdr = hdr->nexthdr;
75f2811c	359	__be16 frag_off;
7bc570c8 YH	360	int offset;
	361
	362	/* Check if the value of Router Alert
	363	* is for MLD (0x0000).
	364	*/
dd3332bf	365	if (opt->ra == htons(IPV6_OPT_ROUTERALERT_MLD)) {
a50feda5	366	deliver = false;
aba6096b	367
7bc570c8 YH	368	if (!ipv6_ext_hdr(nexthdr)) {
7bc570c8 YH	369	/* BUG */
aba6096b	370	goto out;
7bc570c8 YH	371	}
7bc570c8 YH	372	offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
75f2811c	373	&nexthdr, &frag_off);
7bc570c8	374	if (offset < 0)
aba6096b	375	goto out;
7bc570c8	376
4c938d22 A	377	if (ipv6_is_mld(skb, nexthdr, offset))
4c938d22 A	378	deliver = true;
7bc570c8	379
4c938d22	380	goto out;
7bc570c8 YH	381	}
	382	/* unknown RA - process it normally */
	383	}
1da177e4	384
7bc570c8 YH	385	if (deliver)
	386	skb2 = skb_clone(skb, GFP_ATOMIC);
	387	else {
	388	skb2 = skb;
	389	skb = NULL;
	390	}
1ab1457c	391
7bc570c8	392	if (skb2) {
7bc570c8	393	ip6_mr_input(skb2);
1da177e4 LT	394	}
1da177e4 LT	395	}
7bc570c8	396	out:
aba6096b YH	397	#endif
aba6096b YH	398	if (likely(deliver))
1da177e4	399	ip6_input(skb);
aba6096b YH	400	else {
	401	/* discard */
	402	kfree_skb(skb);
1da177e4	403	}
1da177e4 LT	404
	405	return 0;
	406	}