[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>
 *
 *	$Id: ip6_input.c,v 1.19 2000/12/13 18:31:50 davem Exp $
 *
 *	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/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;

	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);

	/*
	 *	IPv6 multicast router mode isnt currently supported.
	 */
#if 0
	if (ipv6_config.multicast_route) {
		int addr_type;

		addr_type = ipv6_addr_type(&hdr->daddr);

		if (!(addr_type & (IPV6_ADDR_LOOPBACK | IPV6_ADDR_LINKLOCAL))) {
			struct sk_buff *skb2;
			struct dst_entry *dst;

			dst = skb->dst;

			if (deliver) {
				skb2 = skb_clone(skb, GFP_ATOMIC);
				dst_output(skb2);
			} else {
				dst_output(skb);
				return 0;
			}
		}
	}
#endif

	if (likely(deliver)) {
		ip6_input(skb);
		return 0;
	}
	/* 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	*
	9	* $Id: ip6_input.c,v 1.19 2000/12/13 18:31:50 davem Exp $
	10	*
	11	* Based in linux/net/ipv4/ip_input.c
	12	*
	13	* This program is free software; you can redistribute it and/or
	14	* modify it under the terms of the GNU General Public License
	15	* as published by the Free Software Foundation; either version
	16	* 2 of the License, or (at your option) any later version.
	17	*/
	18	/* Changes
	19	*
	20	* Mitsuru KANDA @USAGI and
	21	* YOSHIFUJI Hideaki @USAGI: Remove ipv6_parse_exthdrs().
	22	*/
	23
	24	#include <linux/errno.h>
	25	#include <linux/types.h>
	26	#include <linux/socket.h>
	27	#include <linux/sockios.h>
1da177e4 LT	28	#include <linux/net.h>
	29	#include <linux/netdevice.h>
	30	#include <linux/in6.h>
	31	#include <linux/icmpv6.h>
	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 LT	51	{
	52	if (skb->dst == NULL)
	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 LT	59	{
	60	struct ipv6hdr *hdr;
	61	u32 pkt_len;
a11d206d	62	struct inet6_dev *idev;
1da177e4	63
a11d206d YH	64	if (skb->pkt_type == PACKET_OTHERHOST) {
	65	kfree_skb(skb);
	66	return 0;
	67	}
	68
	69	rcu_read_lock();
1da177e4	70
a11d206d YH	71	idev = __in6_dev_get(skb->dev);
	72
	73	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INRECEIVES);
1da177e4 LT	74
1da177e4 LT	75	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
a11d206d YH	76	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS);
a11d206d YH	77	rcu_read_unlock();
1da177e4 LT	78	goto out;
	79	}
	80
6b7fdc3a GC	81	memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
6b7fdc3a GC	82
1da177e4 LT	83	/*
	84	* Store incoming device index. When the packet will
	85	* be queued, we cannot refer to skb->dev anymore.
	86	*
	87	* BTW, when we send a packet for our own local address on a
	88	* non-loopback interface (e.g. ethX), it is being delivered
de3cb747	89	* via the loopback interface (lo) here; skb->dev = loopback_dev.
1da177e4 LT	90	* It, however, should be considered as if it is being
	91	* arrived via the sending interface (ethX), because of the
	92	* nature of scoping architecture. --yoshfuji
	93	*/
7a3025b1	94	IP6CB(skb)->iif = skb->dst ? ip6_dst_idev(skb->dst)->dev->ifindex : dev->ifindex;
1da177e4	95
2889139a	96	if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
1da177e4 LT	97	goto err;
1da177e4 LT	98
0660e03f	99	hdr = ipv6_hdr(skb);
1da177e4 LT	100
	101	if (hdr->version != 6)
	102	goto err;
	103
b0e380b1	104	skb->transport_header = skb->network_header + sizeof(*hdr);
951dbc8a PM	105	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
951dbc8a PM	106
1da177e4 LT	107	pkt_len = ntohs(hdr->payload_len);
	108
	109	/* pkt_len may be zero if Jumbo payload option is present */
	110	if (pkt_len \|\| hdr->nexthdr != NEXTHDR_HOP) {
60e5c166 MC	111	if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
	112	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INTRUNCATEDPKTS);
	113	goto drop;
	114	}
1da177e4	115	if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
a11d206d	116	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
1da177e4 LT	117	goto drop;
1da177e4 LT	118	}
0660e03f	119	hdr = ipv6_hdr(skb);
1da177e4 LT	120	}
	121
	122	if (hdr->nexthdr == NEXTHDR_HOP) {
e5bbef20	123	if (ipv6_parse_hopopts(skb) < 0) {
a11d206d YH	124	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
a11d206d YH	125	rcu_read_unlock();
1da177e4 LT	126	return 0;
1da177e4 LT	127	}
1da177e4 LT	128	}
1da177e4 LT	129
a11d206d YH	130	rcu_read_unlock();
a11d206d YH	131
6e23ae2a PM	132	return NF_HOOK(PF_INET6, NF_INET_PRE_ROUTING, skb, dev, NULL,
6e23ae2a PM	133	ip6_rcv_finish);
1da177e4	134	err:
a11d206d	135	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
1da177e4	136	drop:
a11d206d	137	rcu_read_unlock();
1da177e4 LT	138	kfree_skb(skb);
	139	out:
	140	return 0;
	141	}
	142
	143	/*
	144	* Deliver the packet to the host
	145	*/
	146
	147
ad643a79	148	static int ip6_input_finish(struct sk_buff *skb)
1da177e4 LT	149	{
1da177e4 LT	150	struct inet6_protocol *ipprot;
1da177e4	151	unsigned int nhoff;
69d6da0b	152	int nexthdr, raw;
1da177e4	153	u8 hash;
a11d206d	154	struct inet6_dev *idev;
1da177e4	155
1da177e4 LT	156	/*
	157	* Parse extension headers
	158	*/
	159
1da177e4 LT	160	rcu_read_lock();
1da177e4 LT	161	resubmit:
a11d206d	162	idev = ip6_dst_idev(skb->dst);
ea2ae17d	163	if (!pskb_pull(skb, skb_transport_offset(skb)))
1da177e4	164	goto discard;
951dbc8a	165	nhoff = IP6CB(skb)->nhoff;
d56f90a7	166	nexthdr = skb_network_header(skb)[nhoff];
1da177e4	167
69d6da0b	168	raw = raw6_local_deliver(skb, nexthdr);
1da177e4 LT	169
	170	hash = nexthdr & (MAX_INET_PROTOS - 1);
	171	if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {
	172	int ret;
1ab1457c	173
1da177e4	174	if (ipprot->flags & INET6_PROTO_FINAL) {
1ab1457c	175	struct ipv6hdr *hdr;
1da177e4	176
9fb9cbb1 YK	177	/* Free reference early: we don't need it any more,
	178	and it may hold ip_conntrack module loaded
	179	indefinitely. */
	180	nf_reset(skb);
	181
d56f90a7	182	skb_postpull_rcsum(skb, skb_network_header(skb),
cfe1fc77	183	skb_network_header_len(skb));
0660e03f	184	hdr = ipv6_hdr(skb);
1da177e4 LT	185	if (ipv6_addr_is_multicast(&hdr->daddr) &&
	186	!ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
	187	&hdr->saddr) &&
	188	!ipv6_is_mld(skb, nexthdr))
	189	goto discard;
	190	}
	191	if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
1ab1457c	192	!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1da177e4	193	goto discard;
1ab1457c	194
e5bbef20	195	ret = ipprot->handler(skb);
1da177e4 LT	196	if (ret > 0)
	197	goto resubmit;
	198	else if (ret == 0)
a11d206d	199	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDELIVERS);
1da177e4	200	} else {
69d6da0b	201	if (!raw) {
1da177e4	202	if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
a11d206d	203	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INUNKNOWNPROTOS);
fad87aca	204	icmpv6_send(skb, ICMPV6_PARAMPROB,
1ab1457c YH	205	ICMPV6_UNK_NEXTHDR, nhoff,
1ab1457c YH	206	skb->dev);
1da177e4	207	}
fad87aca	208	} else
a11d206d	209	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDELIVERS);
fad87aca	210	kfree_skb(skb);
1da177e4 LT	211	}
	212	rcu_read_unlock();
	213	return 0;
	214
	215	discard:
a11d206d	216	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS);
1da177e4 LT	217	rcu_read_unlock();
	218	kfree_skb(skb);
	219	return 0;
	220	}
	221
	222
	223	int ip6_input(struct sk_buff *skb)
	224	{
6e23ae2a PM	225	return NF_HOOK(PF_INET6, NF_INET_LOCAL_IN, skb, skb->dev, NULL,
6e23ae2a PM	226	ip6_input_finish);
1da177e4 LT	227	}
	228
	229	int ip6_mc_input(struct sk_buff *skb)
	230	{
	231	struct ipv6hdr *hdr;
	232	int deliver;
	233
a11d206d	234	IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INMCASTPKTS);
1da177e4	235
0660e03f	236	hdr = ipv6_hdr(skb);
4c7966b8	237	deliver = ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
1da177e4 LT	238
	239	/*
	240	* IPv6 multicast router mode isnt currently supported.
	241	*/
	242	#if 0
	243	if (ipv6_config.multicast_route) {
	244	int addr_type;
	245
	246	addr_type = ipv6_addr_type(&hdr->daddr);
	247
	248	if (!(addr_type & (IPV6_ADDR_LOOPBACK \| IPV6_ADDR_LINKLOCAL))) {
	249	struct sk_buff *skb2;
	250	struct dst_entry *dst;
	251
	252	dst = skb->dst;
1ab1457c	253
1da177e4 LT	254	if (deliver) {
	255	skb2 = skb_clone(skb, GFP_ATOMIC);
	256	dst_output(skb2);
	257	} else {
	258	dst_output(skb);
	259	return 0;
	260	}
	261	}
	262	}
	263	#endif
	264
	265	if (likely(deliver)) {
	266	ip6_input(skb);
	267	return 0;
	268	}
	269	/* discard */
	270	kfree_skb(skb);
	271
	272	return 0;
	273	}