[mirror_ubuntu-zesty-kernel.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/sched.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;

	if (skb->pkt_type == PACKET_OTHERHOST)
		goto drop;

	IP6_INC_STATS_BH(IPSTATS_MIB_INRECEIVES);

	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
		IP6_INC_STATS_BH(IPSTATS_MIB_INDISCARDS);
		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 ? ((struct rt6_info *)skb->dst)->rt6i_idev->dev->ifindex : dev->ifindex;

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

	hdr = skb->nh.ipv6h;

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

	skb->h.raw = (u8 *)(hdr + 1);
	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)
			goto truncated;
		if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
			IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
			goto drop;
		}
		hdr = skb->nh.ipv6h;
	}

	if (hdr->nexthdr == NEXTHDR_HOP) {
		if (ipv6_parse_hopopts(skb) < 0) {
			IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
			return 0;
		}
	}

	return NF_HOOK(PF_INET6,NF_IP6_PRE_ROUTING, skb, dev, NULL, ip6_rcv_finish);
truncated:
	IP6_INC_STATS_BH(IPSTATS_MIB_INTRUNCATEDPKTS);
err:
	IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
drop:
	kfree_skb(skb);
out:
	return 0;
}

/*
 *	Deliver the packet to the host
 */


static inline int ip6_input_finish(struct sk_buff *skb)
{
	struct inet6_protocol *ipprot;
	struct sock *raw_sk;
	unsigned int nhoff;
	int nexthdr;
	u8 hash;

	/*
	 *	Parse extension headers
	 */

	rcu_read_lock();
resubmit:
	if (!pskb_pull(skb, skb->h.raw - skb->data))
		goto discard;
	nhoff = IP6CB(skb)->nhoff;
	nexthdr = skb->nh.raw[nhoff];

	raw_sk = sk_head(&raw_v6_htable[nexthdr & (MAX_INET_PROTOS - 1)]);
	if (raw_sk && !ipv6_raw_deliver(skb, nexthdr))
		raw_sk = NULL;

	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->nh.raw,
					   skb->h.raw - skb->nh.raw);
			hdr = skb->nh.ipv6h;
			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(IPSTATS_MIB_INDELIVERS);
	} else {
		if (!raw_sk) {
			if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
				IP6_INC_STATS_BH(IPSTATS_MIB_INUNKNOWNPROTOS);
				icmpv6_send(skb, ICMPV6_PARAMPROB,
				            ICMPV6_UNK_NEXTHDR, nhoff,
				            skb->dev);
			}
		} else
			IP6_INC_STATS_BH(IPSTATS_MIB_INDELIVERS);
		kfree_skb(skb);
	}
	rcu_read_unlock();
	return 0;

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


int ip6_input(struct sk_buff *skb)
{
	return NF_HOOK(PF_INET6,NF_IP6_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(IPSTATS_MIB_INMCASTPKTS);

	hdr = skb->nh.ipv6h;
	deliver = likely(!(skb->dev->flags & (IFF_PROMISC|IFF_ALLMULTI))) ||
	    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	/*
	2	* IPv6 input
	3	* Linux INET6 implementation
	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>
	28	#include <linux/sched.h>
	29	#include <linux/net.h>
	30	#include <linux/netdevice.h>
	31	#include <linux/in6.h>
	32	#include <linux/icmpv6.h>
	33
	34	#include <linux/netfilter.h>
	35	#include <linux/netfilter_ipv6.h>
	36
	37	#include <net/sock.h>
	38	#include <net/snmp.h>
	39
	40	#include <net/ipv6.h>
	41	#include <net/protocol.h>
	42	#include <net/transp_v6.h>
	43	#include <net/rawv6.h>
	44	#include <net/ndisc.h>
	45	#include <net/ip6_route.h>
	46	#include <net/addrconf.h>
	47	#include <net/xfrm.h>
	48
	49
	50
b05e1066	51	inline int ip6_rcv_finish( struct sk_buff *skb)
1da177e4 LT	52	{
	53	if (skb->dst == NULL)
	54	ip6_route_input(skb);
	55
	56	return dst_input(skb);
	57	}
	58
f2ccd8fa	59	int ipv6_rcv(struct sk_buff skb, struct net_device dev, struct packet_type pt, struct net_device orig_dev)
1da177e4 LT	60	{
	61	struct ipv6hdr *hdr;
	62	u32 pkt_len;
	63
	64	if (skb->pkt_type == PACKET_OTHERHOST)
	65	goto drop;
	66
	67	IP6_INC_STATS_BH(IPSTATS_MIB_INRECEIVES);
	68
	69	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
	70	IP6_INC_STATS_BH(IPSTATS_MIB_INDISCARDS);
	71	goto out;
	72	}
	73
6b7fdc3a GC	74	memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
6b7fdc3a GC	75
1da177e4 LT	76	/*
	77	* Store incoming device index. When the packet will
	78	* be queued, we cannot refer to skb->dev anymore.
	79	*
	80	* BTW, when we send a packet for our own local address on a
	81	* non-loopback interface (e.g. ethX), it is being delivered
	82	* via the loopback interface (lo) here; skb->dev = &loopback_dev.
	83	* It, however, should be considered as if it is being
	84	* arrived via the sending interface (ethX), because of the
	85	* nature of scoping architecture. --yoshfuji
	86	*/
	87	IP6CB(skb)->iif = skb->dst ? ((struct rt6_info *)skb->dst)->rt6i_idev->dev->ifindex : dev->ifindex;
	88
2889139a	89	if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
1da177e4 LT	90	goto err;
1da177e4 LT	91
1da177e4 LT	92	hdr = skb->nh.ipv6h;
	93
	94	if (hdr->version != 6)
	95	goto err;
	96
951dbc8a PM	97	skb->h.raw = (u8 *)(hdr + 1);
	98	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
	99
1da177e4 LT	100	pkt_len = ntohs(hdr->payload_len);
	101
	102	/* pkt_len may be zero if Jumbo payload option is present */
	103	if (pkt_len \|\| hdr->nexthdr != NEXTHDR_HOP) {
	104	if (pkt_len + sizeof(struct ipv6hdr) > skb->len)
	105	goto truncated;
	106	if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
	107	IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
	108	goto drop;
	109	}
	110	hdr = skb->nh.ipv6h;
	111	}
	112
	113	if (hdr->nexthdr == NEXTHDR_HOP) {
b809739a	114	if (ipv6_parse_hopopts(skb) < 0) {
1da177e4 LT	115	IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
	116	return 0;
	117	}
1da177e4 LT	118	}
	119
	120	return NF_HOOK(PF_INET6,NF_IP6_PRE_ROUTING, skb, dev, NULL, ip6_rcv_finish);
	121	truncated:
	122	IP6_INC_STATS_BH(IPSTATS_MIB_INTRUNCATEDPKTS);
	123	err:
	124	IP6_INC_STATS_BH(IPSTATS_MIB_INHDRERRORS);
	125	drop:
	126	kfree_skb(skb);
	127	out:
	128	return 0;
	129	}
	130
	131	/*
	132	* Deliver the packet to the host
	133	*/
	134
	135
	136	static inline int ip6_input_finish(struct sk_buff *skb)
	137	{
	138	struct inet6_protocol *ipprot;
	139	struct sock *raw_sk;
	140	unsigned int nhoff;
	141	int nexthdr;
	142	u8 hash;
	143
1da177e4 LT	144	/*
	145	* Parse extension headers
	146	*/
	147
1da177e4 LT	148	rcu_read_lock();
	149	resubmit:
	150	if (!pskb_pull(skb, skb->h.raw - skb->data))
	151	goto discard;
951dbc8a	152	nhoff = IP6CB(skb)->nhoff;
1da177e4 LT	153	nexthdr = skb->nh.raw[nhoff];
	154
	155	raw_sk = sk_head(&raw_v6_htable[nexthdr & (MAX_INET_PROTOS - 1)]);
d13964f4 PM	156	if (raw_sk && !ipv6_raw_deliver(skb, nexthdr))
d13964f4 PM	157	raw_sk = NULL;
1da177e4 LT	158
	159	hash = nexthdr & (MAX_INET_PROTOS - 1);
	160	if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {
	161	int ret;
	162
	163	if (ipprot->flags & INET6_PROTO_FINAL) {
	164	struct ipv6hdr *hdr;
	165
9fb9cbb1 YK	166	/* Free reference early: we don't need it any more,
	167	and it may hold ip_conntrack module loaded
	168	indefinitely. */
	169	nf_reset(skb);
	170
1da177e4 LT	171	skb_postpull_rcsum(skb, skb->nh.raw,
	172	skb->h.raw - skb->nh.raw);
	173	hdr = skb->nh.ipv6h;
	174	if (ipv6_addr_is_multicast(&hdr->daddr) &&
	175	!ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
	176	&hdr->saddr) &&
	177	!ipv6_is_mld(skb, nexthdr))
	178	goto discard;
	179	}
	180	if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
	181	!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
	182	goto discard;
	183
951dbc8a	184	ret = ipprot->handler(&skb);
1da177e4 LT	185	if (ret > 0)
	186	goto resubmit;
	187	else if (ret == 0)
	188	IP6_INC_STATS_BH(IPSTATS_MIB_INDELIVERS);
	189	} else {
	190	if (!raw_sk) {
	191	if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
	192	IP6_INC_STATS_BH(IPSTATS_MIB_INUNKNOWNPROTOS);
fad87aca PM	193	icmpv6_send(skb, ICMPV6_PARAMPROB,
	194	ICMPV6_UNK_NEXTHDR, nhoff,
	195	skb->dev);
1da177e4	196	}
fad87aca	197	} else
1da177e4	198	IP6_INC_STATS_BH(IPSTATS_MIB_INDELIVERS);
fad87aca	199	kfree_skb(skb);
1da177e4 LT	200	}
	201	rcu_read_unlock();
	202	return 0;
	203
	204	discard:
	205	IP6_INC_STATS_BH(IPSTATS_MIB_INDISCARDS);
	206	rcu_read_unlock();
	207	kfree_skb(skb);
	208	return 0;
	209	}
	210
	211
	212	int ip6_input(struct sk_buff *skb)
	213	{
	214	return NF_HOOK(PF_INET6,NF_IP6_LOCAL_IN, skb, skb->dev, NULL, ip6_input_finish);
	215	}
	216
	217	int ip6_mc_input(struct sk_buff *skb)
	218	{
	219	struct ipv6hdr *hdr;
	220	int deliver;
	221
	222	IP6_INC_STATS_BH(IPSTATS_MIB_INMCASTPKTS);
	223
	224	hdr = skb->nh.ipv6h;
	225	deliver = likely(!(skb->dev->flags & (IFF_PROMISC\|IFF_ALLMULTI))) \|\|
	226	ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
	227
	228	/*
	229	* IPv6 multicast router mode isnt currently supported.
	230	*/
	231	#if 0
	232	if (ipv6_config.multicast_route) {
	233	int addr_type;
	234
	235	addr_type = ipv6_addr_type(&hdr->daddr);
	236
	237	if (!(addr_type & (IPV6_ADDR_LOOPBACK \| IPV6_ADDR_LINKLOCAL))) {
	238	struct sk_buff *skb2;
	239	struct dst_entry *dst;
	240
	241	dst = skb->dst;
	242
	243	if (deliver) {
	244	skb2 = skb_clone(skb, GFP_ATOMIC);
	245	dst_output(skb2);
	246	} else {
	247	dst_output(skb);
	248	return 0;
	249	}
	250	}
	251	}
	252	#endif
	253
	254	if (likely(deliver)) {
	255	ip6_input(skb);
	256	return 0;
	257	}
	258	/* discard */
	259	kfree_skb(skb);
	260
	261	return 0;
	262	}