[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/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 == 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)
{
	struct ipv6hdr *hdr;
	u32 		pkt_len;
	struct inet6_dev *idev;

	if (skb->pkt_type == PACKET_OTHERHOST) {
		kfree_skb(skb);
		return 0;
	}

	rcu_read_lock();

	idev = __in6_dev_get(skb->dev);

	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INRECEIVES);

	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
		IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS);
		rcu_read_unlock();
		goto out;
	}

	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 ? ip6_dst_idev(skb->dst)->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;

	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(idev, IPSTATS_MIB_INTRUNCATEDPKTS);
			goto drop;
		}
		if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
			IP6_INC_STATS_BH(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(idev, IPSTATS_MIB_INHDRERRORS);
			rcu_read_unlock();
			return 0;
		}
	}

	rcu_read_unlock();

	return NF_HOOK(PF_INET6, NF_INET_PRE_ROUTING, skb, dev, NULL,
		       ip6_rcv_finish);
err:
	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
drop:
	rcu_read_unlock();
	kfree_skb(skb);
out:
	return 0;
}

/*
 *	Deliver the packet to the host
 */


static int ip6_input_finish(struct sk_buff *skb)
{
	struct inet6_protocol *ipprot;
	unsigned int nhoff;
	int nexthdr, raw;
	u8 hash;
	struct inet6_dev *idev;

	/*
	 *	Parse extension headers
	 */

	rcu_read_lock();
resubmit:
	idev = ip6_dst_idev(skb->dst);
	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) {
			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(idev, IPSTATS_MIB_INDELIVERS);
	} else {
		if (!raw) {
			if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
				IP6_INC_STATS_BH(idev, IPSTATS_MIB_INUNKNOWNPROTOS);
				icmpv6_send(skb, ICMPV6_PARAMPROB,
					    ICMPV6_UNK_NEXTHDR, nhoff,
					    skb->dev);
			}
		} else
			IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDELIVERS);
		kfree_skb(skb);
	}
	rcu_read_unlock();
	return 0;

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


int ip6_input(struct sk_buff *skb)
{
	return NF_HOOK(PF_INET6, NF_INET_LOCAL_IN, skb, skb->dev, NULL,
		       ip6_input_finish);
}

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

	IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INMCASTPKTS);

	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 (ipv6_devconf.mc_forwarding &&
	    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;
			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);
				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) {
			skb2->dev = skb2->dst->dev;
			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>
1da177e4 LT	31
	32	#include <linux/netfilter.h>
	33	#include <linux/netfilter_ipv6.h>
	34
	35	#include <net/sock.h>
	36	#include <net/snmp.h>
	37
	38	#include <net/ipv6.h>
	39	#include <net/protocol.h>
	40	#include <net/transp_v6.h>
	41	#include <net/rawv6.h>
	42	#include <net/ndisc.h>
	43	#include <net/ip6_route.h>
	44	#include <net/addrconf.h>
	45	#include <net/xfrm.h>
	46
	47
	48
1ab1457c	49	inline int ip6_rcv_finish( struct sk_buff *skb)
1da177e4 LT	50	{
	51	if (skb->dst == NULL)
	52	ip6_route_input(skb);
	53
	54	return dst_input(skb);
	55	}
	56
f2ccd8fa	57	int ipv6_rcv(struct sk_buff skb, struct net_device dev, struct packet_type pt, struct net_device orig_dev)
1da177e4 LT	58	{
	59	struct ipv6hdr *hdr;
	60	u32 pkt_len;
a11d206d	61	struct inet6_dev *idev;
1da177e4	62
a11d206d YH	63	if (skb->pkt_type == PACKET_OTHERHOST) {
	64	kfree_skb(skb);
	65	return 0;
	66	}
	67
	68	rcu_read_lock();
1da177e4	69
a11d206d YH	70	idev = __in6_dev_get(skb->dev);
	71
	72	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INRECEIVES);
1da177e4 LT	73
1da177e4 LT	74	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
a11d206d YH	75	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS);
a11d206d YH	76	rcu_read_unlock();
1da177e4 LT	77	goto out;
	78	}
	79
6b7fdc3a GC	80	memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
6b7fdc3a GC	81
1da177e4 LT	82	/*
	83	* Store incoming device index. When the packet will
	84	* be queued, we cannot refer to skb->dev anymore.
	85	*
	86	* BTW, when we send a packet for our own local address on a
	87	* non-loopback interface (e.g. ethX), it is being delivered
de3cb747	88	* via the loopback interface (lo) here; skb->dev = loopback_dev.
1da177e4 LT	89	* It, however, should be considered as if it is being
	90	* arrived via the sending interface (ethX), because of the
	91	* nature of scoping architecture. --yoshfuji
	92	*/
7a3025b1	93	IP6CB(skb)->iif = skb->dst ? ip6_dst_idev(skb->dst)->dev->ifindex : dev->ifindex;
1da177e4	94
2889139a	95	if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
1da177e4 LT	96	goto err;
1da177e4 LT	97
0660e03f	98	hdr = ipv6_hdr(skb);
1da177e4 LT	99
	100	if (hdr->version != 6)
	101	goto err;
	102
f630e43a YH	103	/*
	104	* RFC4291 2.5.3
	105	* A packet received on an interface with a destination address
	106	* of loopback must be dropped.
	107	*/
	108	if (!(dev->flags & IFF_LOOPBACK) &&
	109	ipv6_addr_loopback(&hdr->daddr))
	110	goto err;
	111
b0e380b1	112	skb->transport_header = skb->network_header + sizeof(*hdr);
951dbc8a PM	113	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
951dbc8a PM	114
1da177e4 LT	115	pkt_len = ntohs(hdr->payload_len);
	116
	117	/* pkt_len may be zero if Jumbo payload option is present */
	118	if (pkt_len \|\| hdr->nexthdr != NEXTHDR_HOP) {
60e5c166 MC	119	if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
	120	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INTRUNCATEDPKTS);
	121	goto drop;
	122	}
1da177e4	123	if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
a11d206d	124	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
1da177e4 LT	125	goto drop;
1da177e4 LT	126	}
0660e03f	127	hdr = ipv6_hdr(skb);
1da177e4 LT	128	}
	129
	130	if (hdr->nexthdr == NEXTHDR_HOP) {
e5bbef20	131	if (ipv6_parse_hopopts(skb) < 0) {
a11d206d YH	132	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
a11d206d YH	133	rcu_read_unlock();
1da177e4 LT	134	return 0;
1da177e4 LT	135	}
1da177e4 LT	136	}
1da177e4 LT	137
a11d206d YH	138	rcu_read_unlock();
a11d206d YH	139
6e23ae2a PM	140	return NF_HOOK(PF_INET6, NF_INET_PRE_ROUTING, skb, dev, NULL,
6e23ae2a PM	141	ip6_rcv_finish);
1da177e4	142	err:
a11d206d	143	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
1da177e4	144	drop:
a11d206d	145	rcu_read_unlock();
1da177e4 LT	146	kfree_skb(skb);
	147	out:
	148	return 0;
	149	}
	150
	151	/*
	152	* Deliver the packet to the host
	153	*/
	154
	155
ad643a79	156	static int ip6_input_finish(struct sk_buff *skb)
1da177e4 LT	157	{
1da177e4 LT	158	struct inet6_protocol *ipprot;
1da177e4	159	unsigned int nhoff;
69d6da0b	160	int nexthdr, raw;
1da177e4	161	u8 hash;
a11d206d	162	struct inet6_dev *idev;
1da177e4	163
1da177e4 LT	164	/*
	165	* Parse extension headers
	166	*/
	167
1da177e4 LT	168	rcu_read_lock();
1da177e4 LT	169	resubmit:
a11d206d	170	idev = ip6_dst_idev(skb->dst);
ea2ae17d	171	if (!pskb_pull(skb, skb_transport_offset(skb)))
1da177e4	172	goto discard;
951dbc8a	173	nhoff = IP6CB(skb)->nhoff;
d56f90a7	174	nexthdr = skb_network_header(skb)[nhoff];
1da177e4	175
69d6da0b	176	raw = raw6_local_deliver(skb, nexthdr);
1da177e4 LT	177
	178	hash = nexthdr & (MAX_INET_PROTOS - 1);
	179	if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {
	180	int ret;
1ab1457c	181
1da177e4	182	if (ipprot->flags & INET6_PROTO_FINAL) {
1ab1457c	183	struct ipv6hdr *hdr;
1da177e4	184
9fb9cbb1 YK	185	/* Free reference early: we don't need it any more,
	186	and it may hold ip_conntrack module loaded
	187	indefinitely. */
	188	nf_reset(skb);
	189
d56f90a7	190	skb_postpull_rcsum(skb, skb_network_header(skb),
cfe1fc77	191	skb_network_header_len(skb));
0660e03f	192	hdr = ipv6_hdr(skb);
1da177e4 LT	193	if (ipv6_addr_is_multicast(&hdr->daddr) &&
	194	!ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
	195	&hdr->saddr) &&
	196	!ipv6_is_mld(skb, nexthdr))
	197	goto discard;
	198	}
	199	if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
1ab1457c	200	!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1da177e4	201	goto discard;
1ab1457c	202
e5bbef20	203	ret = ipprot->handler(skb);
1da177e4 LT	204	if (ret > 0)
	205	goto resubmit;
	206	else if (ret == 0)
a11d206d	207	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDELIVERS);
1da177e4	208	} else {
69d6da0b	209	if (!raw) {
1da177e4	210	if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
a11d206d	211	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INUNKNOWNPROTOS);
fad87aca	212	icmpv6_send(skb, ICMPV6_PARAMPROB,
1ab1457c YH	213	ICMPV6_UNK_NEXTHDR, nhoff,
1ab1457c YH	214	skb->dev);
1da177e4	215	}
fad87aca	216	} else
a11d206d	217	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDELIVERS);
fad87aca	218	kfree_skb(skb);
1da177e4 LT	219	}
	220	rcu_read_unlock();
	221	return 0;
	222
	223	discard:
a11d206d	224	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS);
1da177e4 LT	225	rcu_read_unlock();
	226	kfree_skb(skb);
	227	return 0;
	228	}
	229
	230
	231	int ip6_input(struct sk_buff *skb)
	232	{
6e23ae2a PM	233	return NF_HOOK(PF_INET6, NF_INET_LOCAL_IN, skb, skb->dev, NULL,
6e23ae2a PM	234	ip6_input_finish);
1da177e4 LT	235	}
	236
	237	int ip6_mc_input(struct sk_buff *skb)
	238	{
	239	struct ipv6hdr *hdr;
	240	int deliver;
	241
a11d206d	242	IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INMCASTPKTS);
1da177e4	243
0660e03f	244	hdr = ipv6_hdr(skb);
4c7966b8	245	deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
1da177e4	246
7bc570c8	247	#ifdef CONFIG_IPV6_MROUTE
1da177e4	248	/*
7bc570c8	249	* IPv6 multicast router mode is now supported ;)
1da177e4	250	*/
7bc570c8 YH	251	if (ipv6_devconf.mc_forwarding &&
	252	likely(!(IP6CB(skb)->flags & IP6SKB_FORWARDED))) {
	253	/*
	254	* Okay, we try to forward - split and duplicate
	255	* packets.
	256	*/
	257	struct sk_buff *skb2;
	258	struct inet6_skb_parm *opt = IP6CB(skb);
	259
	260	/* Check for MLD */
	261	if (unlikely(opt->ra)) {
	262	/* Check if this is a mld message */
	263	u8 *ptr = skb_network_header(skb) + opt->ra;
	264	struct icmp6hdr *icmp6;
	265	u8 nexthdr = hdr->nexthdr;
	266	int offset;
	267
	268	/* Check if the value of Router Alert
	269	* is for MLD (0x0000).
	270	*/
	271	if ((ptr[2] \| ptr[3]) == 0) {
aba6096b YH	272	deliver = 0;
aba6096b YH	273
7bc570c8 YH	274	if (!ipv6_ext_hdr(nexthdr)) {
7bc570c8 YH	275	/* BUG */
aba6096b	276	goto out;
7bc570c8 YH	277	}
	278	offset = ipv6_skip_exthdr(skb, sizeof(*hdr),
	279	&nexthdr);
	280	if (offset < 0)
aba6096b	281	goto out;
7bc570c8 YH	282
7bc570c8 YH	283	if (nexthdr != IPPROTO_ICMPV6)
aba6096b	284	goto out;
7bc570c8 YH	285
	286	if (!pskb_may_pull(skb, (skb_network_header(skb) +
	287	offset + 1 - skb->data)))
aba6096b	288	goto out;
7bc570c8 YH	289
	290	icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset);
	291
	292	switch (icmp6->icmp6_type) {
	293	case ICMPV6_MGM_QUERY:
	294	case ICMPV6_MGM_REPORT:
	295	case ICMPV6_MGM_REDUCTION:
	296	case ICMPV6_MLD2_REPORT:
aba6096b	297	deliver = 1;
7bc570c8	298	break;
7bc570c8	299	}
7bc570c8 YH	300	goto out;
	301	}
	302	/* unknown RA - process it normally */
	303	}
1da177e4	304
7bc570c8 YH	305	if (deliver)
	306	skb2 = skb_clone(skb, GFP_ATOMIC);
	307	else {
	308	skb2 = skb;
	309	skb = NULL;
	310	}
1ab1457c	311
7bc570c8 YH	312	if (skb2) {
	313	skb2->dev = skb2->dst->dev;
	314	ip6_mr_input(skb2);
1da177e4 LT	315	}
1da177e4 LT	316	}
7bc570c8	317	out:
aba6096b YH	318	#endif
aba6096b YH	319	if (likely(deliver))
1da177e4	320	ip6_input(skb);
aba6096b YH	321	else {
	322	/* discard */
	323	kfree_skb(skb);
1da177e4	324	}
1da177e4 LT	325
	326	return 0;
	327	}