[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/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 (dev->nd_net != &init_net) {
		kfree_skb(skb);
		return 0;
	}

	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_IP6_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 inline int ip6_input_finish(struct sk_buff *skb)
{
	struct inet6_protocol *ipprot;
	struct sock *raw_sk;
	unsigned int nhoff;
	int nexthdr;
	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_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_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_sk) {
			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_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(ip6_dst_idev(skb->dst), IPSTATS_MIB_INMCASTPKTS);

	hdr = ipv6_hdr(skb);
	deliver = unlikely(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	/*
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
e730c155 EB	64	if (dev->nd_net != &init_net) {
	65	kfree_skb(skb);
	66	return 0;
	67	}
	68
a11d206d YH	69	if (skb->pkt_type == PACKET_OTHERHOST) {
	70	kfree_skb(skb);
	71	return 0;
	72	}
	73
	74	rcu_read_lock();
1da177e4	75
a11d206d YH	76	idev = __in6_dev_get(skb->dev);
	77
	78	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INRECEIVES);
1da177e4 LT	79
1da177e4 LT	80	if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
a11d206d YH	81	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS);
a11d206d YH	82	rcu_read_unlock();
1da177e4 LT	83	goto out;
	84	}
	85
6b7fdc3a GC	86	memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
6b7fdc3a GC	87
1da177e4 LT	88	/*
	89	* Store incoming device index. When the packet will
	90	* be queued, we cannot refer to skb->dev anymore.
	91	*
	92	* BTW, when we send a packet for our own local address on a
	93	* non-loopback interface (e.g. ethX), it is being delivered
de3cb747	94	* via the loopback interface (lo) here; skb->dev = loopback_dev.
1da177e4 LT	95	* It, however, should be considered as if it is being
	96	* arrived via the sending interface (ethX), because of the
	97	* nature of scoping architecture. --yoshfuji
	98	*/
7a3025b1	99	IP6CB(skb)->iif = skb->dst ? ip6_dst_idev(skb->dst)->dev->ifindex : dev->ifindex;
1da177e4	100
2889139a	101	if (unlikely(!pskb_may_pull(skb, sizeof(*hdr))))
1da177e4 LT	102	goto err;
1da177e4 LT	103
0660e03f	104	hdr = ipv6_hdr(skb);
1da177e4 LT	105
	106	if (hdr->version != 6)
	107	goto err;
	108
b0e380b1	109	skb->transport_header = skb->network_header + sizeof(*hdr);
951dbc8a PM	110	IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
951dbc8a PM	111
1da177e4 LT	112	pkt_len = ntohs(hdr->payload_len);
	113
	114	/* pkt_len may be zero if Jumbo payload option is present */
	115	if (pkt_len \|\| hdr->nexthdr != NEXTHDR_HOP) {
60e5c166 MC	116	if (pkt_len + sizeof(struct ipv6hdr) > skb->len) {
	117	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INTRUNCATEDPKTS);
	118	goto drop;
	119	}
1da177e4	120	if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) {
a11d206d	121	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
1da177e4 LT	122	goto drop;
1da177e4 LT	123	}
0660e03f	124	hdr = ipv6_hdr(skb);
1da177e4 LT	125	}
	126
	127	if (hdr->nexthdr == NEXTHDR_HOP) {
a80ff03e	128	if (ipv6_parse_hopopts(&skb) < 0) {
a11d206d YH	129	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
a11d206d YH	130	rcu_read_unlock();
1da177e4 LT	131	return 0;
1da177e4 LT	132	}
1da177e4 LT	133	}
1da177e4 LT	134
a11d206d YH	135	rcu_read_unlock();
a11d206d YH	136
1da177e4	137	return NF_HOOK(PF_INET6,NF_IP6_PRE_ROUTING, skb, dev, NULL, ip6_rcv_finish);
1da177e4	138	err:
a11d206d	139	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INHDRERRORS);
1da177e4	140	drop:
a11d206d	141	rcu_read_unlock();
1da177e4 LT	142	kfree_skb(skb);
	143	out:
	144	return 0;
	145	}
	146
	147	/*
	148	* Deliver the packet to the host
	149	*/
	150
	151
	152	static inline int ip6_input_finish(struct sk_buff *skb)
	153	{
	154	struct inet6_protocol *ipprot;
	155	struct sock *raw_sk;
	156	unsigned int nhoff;
	157	int nexthdr;
	158	u8 hash;
a11d206d	159	struct inet6_dev *idev;
1da177e4	160
1da177e4 LT	161	/*
	162	* Parse extension headers
	163	*/
	164
1da177e4 LT	165	rcu_read_lock();
1da177e4 LT	166	resubmit:
a11d206d	167	idev = ip6_dst_idev(skb->dst);
ea2ae17d	168	if (!pskb_pull(skb, skb_transport_offset(skb)))
1da177e4	169	goto discard;
951dbc8a	170	nhoff = IP6CB(skb)->nhoff;
d56f90a7	171	nexthdr = skb_network_header(skb)[nhoff];
1da177e4 LT	172
1da177e4 LT	173	raw_sk = sk_head(&raw_v6_htable[nexthdr & (MAX_INET_PROTOS - 1)]);
d13964f4 PM	174	if (raw_sk && !ipv6_raw_deliver(skb, nexthdr))
d13964f4 PM	175	raw_sk = NULL;
1da177e4 LT	176
	177	hash = nexthdr & (MAX_INET_PROTOS - 1);
	178	if ((ipprot = rcu_dereference(inet6_protos[hash])) != NULL) {
	179	int ret;
1ab1457c	180
1da177e4	181	if (ipprot->flags & INET6_PROTO_FINAL) {
1ab1457c	182	struct ipv6hdr *hdr;
1da177e4	183
9fb9cbb1 YK	184	/* Free reference early: we don't need it any more,
	185	and it may hold ip_conntrack module loaded
	186	indefinitely. */
	187	nf_reset(skb);
	188
d56f90a7	189	skb_postpull_rcsum(skb, skb_network_header(skb),
cfe1fc77	190	skb_network_header_len(skb));
0660e03f	191	hdr = ipv6_hdr(skb);
1da177e4 LT	192	if (ipv6_addr_is_multicast(&hdr->daddr) &&
	193	!ipv6_chk_mcast_addr(skb->dev, &hdr->daddr,
	194	&hdr->saddr) &&
	195	!ipv6_is_mld(skb, nexthdr))
	196	goto discard;
	197	}
	198	if (!(ipprot->flags & INET6_PROTO_NOPOLICY) &&
1ab1457c	199	!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
1da177e4	200	goto discard;
1ab1457c	201
951dbc8a	202	ret = ipprot->handler(&skb);
1da177e4 LT	203	if (ret > 0)
	204	goto resubmit;
	205	else if (ret == 0)
a11d206d	206	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDELIVERS);
1da177e4 LT	207	} else {
	208	if (!raw_sk) {
	209	if (xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
a11d206d	210	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INUNKNOWNPROTOS);
fad87aca	211	icmpv6_send(skb, ICMPV6_PARAMPROB,
1ab1457c YH	212	ICMPV6_UNK_NEXTHDR, nhoff,
1ab1457c YH	213	skb->dev);
1da177e4	214	}
fad87aca	215	} else
a11d206d	216	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDELIVERS);
fad87aca	217	kfree_skb(skb);
1da177e4 LT	218	}
	219	rcu_read_unlock();
	220	return 0;
	221
	222	discard:
a11d206d	223	IP6_INC_STATS_BH(idev, IPSTATS_MIB_INDISCARDS);
1da177e4 LT	224	rcu_read_unlock();
	225	kfree_skb(skb);
	226	return 0;
	227	}
	228
	229
	230	int ip6_input(struct sk_buff *skb)
	231	{
	232	return NF_HOOK(PF_INET6,NF_IP6_LOCAL_IN, skb, skb->dev, NULL, ip6_input_finish);
	233	}
	234
	235	int ip6_mc_input(struct sk_buff *skb)
	236	{
	237	struct ipv6hdr *hdr;
	238	int deliver;
	239
a11d206d	240	IP6_INC_STATS_BH(ip6_dst_idev(skb->dst), IPSTATS_MIB_INMCASTPKTS);
1da177e4	241
0660e03f	242	hdr = ipv6_hdr(skb);
ae7bf20a	243	deliver = unlikely(skb->dev->flags & (IFF_PROMISC\|IFF_ALLMULTI)) \|\|
1da177e4 LT	244	ipv6_chk_mcast_addr(skb->dev, &hdr->daddr, NULL);
	245
	246	/*
	247	* IPv6 multicast router mode isnt currently supported.
	248	*/
	249	#if 0
	250	if (ipv6_config.multicast_route) {
	251	int addr_type;
	252
	253	addr_type = ipv6_addr_type(&hdr->daddr);
	254
	255	if (!(addr_type & (IPV6_ADDR_LOOPBACK \| IPV6_ADDR_LINKLOCAL))) {
	256	struct sk_buff *skb2;
	257	struct dst_entry *dst;
	258
	259	dst = skb->dst;
1ab1457c	260
1da177e4 LT	261	if (deliver) {
	262	skb2 = skb_clone(skb, GFP_ATOMIC);
	263	dst_output(skb2);
	264	} else {
	265	dst_output(skb);
	266	return 0;
	267	}
	268	}
	269	}
	270	#endif
	271
	272	if (likely(deliver)) {
	273	ip6_input(skb);
	274	return 0;
	275	}
	276	/* discard */
	277	kfree_skb(skb);
	278
	279	return 0;
	280	}