[deliverable/linux.git] / net / ipv6 / netfilter / nf_conntrack_l3proto_ipv6.c

/*
 * Copyright (C)2004 USAGI/WIDE Project
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Author:
 *	Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
 */

#include <linux/types.h>
#include <linux/ipv6.h>
#include <linux/in6.h>
#include <linux/netfilter.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/icmp.h>
#include <linux/sysctl.h>
#include <net/ipv6.h>
#include <net/inet_frag.h>

#include <linux/netfilter_ipv6.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_l3proto.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
#include <net/netfilter/nf_log.h>

static bool ipv6_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
			      struct nf_conntrack_tuple *tuple)
{
	const u_int32_t *ap;
	u_int32_t _addrs[8];

	ap = skb_header_pointer(skb, nhoff + offsetof(struct ipv6hdr, saddr),
				sizeof(_addrs), _addrs);
	if (ap == NULL)
		return false;

	memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6));
	memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6));

	return true;
}

static bool ipv6_invert_tuple(struct nf_conntrack_tuple *tuple,
			      const struct nf_conntrack_tuple *orig)
{
	memcpy(tuple->src.u3.ip6, orig->dst.u3.ip6, sizeof(tuple->src.u3.ip6));
	memcpy(tuple->dst.u3.ip6, orig->src.u3.ip6, sizeof(tuple->dst.u3.ip6));

	return true;
}

static int ipv6_print_tuple(struct seq_file *s,
			    const struct nf_conntrack_tuple *tuple)
{
	return seq_printf(s, "src=%pI6 dst=%pI6 ",
			  tuple->src.u3.ip6, tuple->dst.u3.ip6);
}

/*
 * Based on ipv6_skip_exthdr() in net/ipv6/exthdr.c
 *
 * This function parses (probably truncated) exthdr set "hdr"
 * of length "len". "nexthdrp" initially points to some place,
 * where type of the first header can be found.
 *
 * It skips all well-known exthdrs, and returns pointer to the start
 * of unparsable area i.e. the first header with unknown type.
 * if success, *nexthdr is updated by type/protocol of this header.
 *
 * NOTES: - it may return pointer pointing beyond end of packet,
 *          if the last recognized header is truncated in the middle.
 *        - if packet is truncated, so that all parsed headers are skipped,
 *          it returns -1.
 *        - if packet is fragmented, return pointer of the fragment header.
 *        - ESP is unparsable for now and considered like
 *          normal payload protocol.
 *        - Note also special handling of AUTH header. Thanks to IPsec wizards.
 */

static int nf_ct_ipv6_skip_exthdr(const struct sk_buff *skb, int start,
				  u8 *nexthdrp, int len)
{
	u8 nexthdr = *nexthdrp;

	while (ipv6_ext_hdr(nexthdr)) {
		struct ipv6_opt_hdr hdr;
		int hdrlen;

		if (len < (int)sizeof(struct ipv6_opt_hdr))
			return -1;
		if (nexthdr == NEXTHDR_NONE)
			break;
		if (nexthdr == NEXTHDR_FRAGMENT)
			break;
		if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
			BUG();
		if (nexthdr == NEXTHDR_AUTH)
			hdrlen = (hdr.hdrlen+2)<<2;
		else
			hdrlen = ipv6_optlen(&hdr);

		nexthdr = hdr.nexthdr;
		len -= hdrlen;
		start += hdrlen;
	}

	*nexthdrp = nexthdr;
	return start;
}

static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
			    unsigned int *dataoff, u_int8_t *protonum)
{
	unsigned int extoff = nhoff + sizeof(struct ipv6hdr);
	unsigned char pnum;
	int protoff;

	if (skb_copy_bits(skb, nhoff + offsetof(struct ipv6hdr, nexthdr),
			  &pnum, sizeof(pnum)) != 0) {
		pr_debug("ip6_conntrack_core: can't get nexthdr\n");
		return -NF_ACCEPT;
	}
	protoff = nf_ct_ipv6_skip_exthdr(skb, extoff, &pnum, skb->len - extoff);
	/*
	 * (protoff == skb->len) mean that the packet doesn't have no data
	 * except of IPv6 & ext headers. but it's tracked anyway. - YK
	 */
	if ((protoff < 0) || (protoff > skb->len)) {
		pr_debug("ip6_conntrack_core: can't find proto in pkt\n");
		return -NF_ACCEPT;
	}

	*dataoff = protoff;
	*protonum = pnum;
	return NF_ACCEPT;
}

static unsigned int ipv6_confirm(unsigned int hooknum,
				 struct sk_buff *skb,
				 const struct net_device *in,
				 const struct net_device *out,
				 int (*okfn)(struct sk_buff *))
{
	struct nf_conn *ct;
	const struct nf_conn_help *help;
	const struct nf_conntrack_helper *helper;
	enum ip_conntrack_info ctinfo;
	unsigned int ret, protoff;
	unsigned int extoff = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
	unsigned char pnum = ipv6_hdr(skb)->nexthdr;


	/* This is where we call the helper: as the packet goes out. */
	ct = nf_ct_get(skb, &ctinfo);
	if (!ct || ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY)
		goto out;

	help = nfct_help(ct);
	if (!help)
		goto out;
	/* rcu_read_lock()ed by nf_hook_slow */
	helper = rcu_dereference(help->helper);
	if (!helper)
		goto out;

	protoff = nf_ct_ipv6_skip_exthdr(skb, extoff, &pnum,
					 skb->len - extoff);
	if (protoff > skb->len || pnum == NEXTHDR_FRAGMENT) {
		pr_debug("proto header not found\n");
		return NF_ACCEPT;
	}

	ret = helper->help(skb, protoff, ct, ctinfo);
	if (ret != NF_ACCEPT) {
		nf_log_packet(NFPROTO_IPV6, hooknum, skb, in, out, NULL,
			      "nf_ct_%s: dropping packet", helper->name);
		return ret;
	}
out:
	/* We've seen it coming out the other side: confirm it */
	return nf_conntrack_confirm(skb);
}

static enum ip6_defrag_users nf_ct6_defrag_user(unsigned int hooknum,
						struct sk_buff *skb)
{
	if (hooknum == NF_INET_PRE_ROUTING)
		return IP6_DEFRAG_CONNTRACK_IN;
	else
		return IP6_DEFRAG_CONNTRACK_OUT;

}

static unsigned int ipv6_defrag(unsigned int hooknum,
				struct sk_buff *skb,
				const struct net_device *in,
				const struct net_device *out,
				int (*okfn)(struct sk_buff *))
{
	struct sk_buff *reasm;

	/* Previously seen (loopback)?  */
	if (skb->nfct)
		return NF_ACCEPT;

	reasm = nf_ct_frag6_gather(skb, nf_ct6_defrag_user(hooknum, skb));
	/* queued */
	if (reasm == NULL)
		return NF_STOLEN;

	/* error occured or not fragmented */
	if (reasm == skb)
		return NF_ACCEPT;

	nf_ct_frag6_output(hooknum, reasm, (struct net_device *)in,
			   (struct net_device *)out, okfn);

	return NF_STOLEN;
}

static unsigned int __ipv6_conntrack_in(struct net *net,
					unsigned int hooknum,
					struct sk_buff *skb,
					int (*okfn)(struct sk_buff *))
{
	struct sk_buff *reasm = skb->nfct_reasm;

	/* This packet is fragmented and has reassembled packet. */
	if (reasm) {
		/* Reassembled packet isn't parsed yet ? */
		if (!reasm->nfct) {
			unsigned int ret;

			ret = nf_conntrack_in(net, PF_INET6, hooknum, reasm);
			if (ret != NF_ACCEPT)
				return ret;
		}
		nf_conntrack_get(reasm->nfct);
		skb->nfct = reasm->nfct;
		skb->nfctinfo = reasm->nfctinfo;
		return NF_ACCEPT;
	}

	return nf_conntrack_in(net, PF_INET6, hooknum, skb);
}

static unsigned int ipv6_conntrack_in(unsigned int hooknum,
				      struct sk_buff *skb,
				      const struct net_device *in,
				      const struct net_device *out,
				      int (*okfn)(struct sk_buff *))
{
	return __ipv6_conntrack_in(dev_net(in), hooknum, skb, okfn);
}

static unsigned int ipv6_conntrack_local(unsigned int hooknum,
					 struct sk_buff *skb,
					 const struct net_device *in,
					 const struct net_device *out,
					 int (*okfn)(struct sk_buff *))
{
	/* root is playing with raw sockets. */
	if (skb->len < sizeof(struct ipv6hdr)) {
		if (net_ratelimit())
			printk("ipv6_conntrack_local: packet too short\n");
		return NF_ACCEPT;
	}
	return __ipv6_conntrack_in(dev_net(out), hooknum, skb, okfn);
}

static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = {
	{
		.hook		= ipv6_defrag,
		.owner		= THIS_MODULE,
		.pf		= NFPROTO_IPV6,
		.hooknum	= NF_INET_PRE_ROUTING,
		.priority	= NF_IP6_PRI_CONNTRACK_DEFRAG,
	},
	{
		.hook		= ipv6_conntrack_in,
		.owner		= THIS_MODULE,
		.pf		= NFPROTO_IPV6,
		.hooknum	= NF_INET_PRE_ROUTING,
		.priority	= NF_IP6_PRI_CONNTRACK,
	},
	{
		.hook		= ipv6_conntrack_local,
		.owner		= THIS_MODULE,
		.pf		= NFPROTO_IPV6,
		.hooknum	= NF_INET_LOCAL_OUT,
		.priority	= NF_IP6_PRI_CONNTRACK,
	},
	{
		.hook		= ipv6_defrag,
		.owner		= THIS_MODULE,
		.pf		= NFPROTO_IPV6,
		.hooknum	= NF_INET_LOCAL_OUT,
		.priority	= NF_IP6_PRI_CONNTRACK_DEFRAG,
	},
	{
		.hook		= ipv6_confirm,
		.owner		= THIS_MODULE,
		.pf		= NFPROTO_IPV6,
		.hooknum	= NF_INET_POST_ROUTING,
		.priority	= NF_IP6_PRI_LAST,
	},
	{
		.hook		= ipv6_confirm,
		.owner		= THIS_MODULE,
		.pf		= NFPROTO_IPV6,
		.hooknum	= NF_INET_LOCAL_IN,
		.priority	= NF_IP6_PRI_LAST-1,
	},
};

#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)

#include <linux/netfilter/nfnetlink.h>
#include <linux/netfilter/nfnetlink_conntrack.h>

static int ipv6_tuple_to_nlattr(struct sk_buff *skb,
				const struct nf_conntrack_tuple *tuple)
{
	NLA_PUT(skb, CTA_IP_V6_SRC, sizeof(u_int32_t) * 4,
		&tuple->src.u3.ip6);
	NLA_PUT(skb, CTA_IP_V6_DST, sizeof(u_int32_t) * 4,
		&tuple->dst.u3.ip6);
	return 0;

nla_put_failure:
	return -1;
}

static const struct nla_policy ipv6_nla_policy[CTA_IP_MAX+1] = {
	[CTA_IP_V6_SRC]	= { .len = sizeof(u_int32_t)*4 },
	[CTA_IP_V6_DST]	= { .len = sizeof(u_int32_t)*4 },
};

static int ipv6_nlattr_to_tuple(struct nlattr *tb[],
				struct nf_conntrack_tuple *t)
{
	if (!tb[CTA_IP_V6_SRC] || !tb[CTA_IP_V6_DST])
		return -EINVAL;

	memcpy(&t->src.u3.ip6, nla_data(tb[CTA_IP_V6_SRC]),
	       sizeof(u_int32_t) * 4);
	memcpy(&t->dst.u3.ip6, nla_data(tb[CTA_IP_V6_DST]),
	       sizeof(u_int32_t) * 4);

	return 0;
}

static int ipv6_nlattr_tuple_size(void)
{
	return nla_policy_len(ipv6_nla_policy, CTA_IP_MAX + 1);
}
#endif

struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 __read_mostly = {
	.l3proto		= PF_INET6,
	.name			= "ipv6",
	.pkt_to_tuple		= ipv6_pkt_to_tuple,
	.invert_tuple		= ipv6_invert_tuple,
	.print_tuple		= ipv6_print_tuple,
	.get_l4proto		= ipv6_get_l4proto,
#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
	.tuple_to_nlattr	= ipv6_tuple_to_nlattr,
	.nlattr_tuple_size	= ipv6_nlattr_tuple_size,
	.nlattr_to_tuple	= ipv6_nlattr_to_tuple,
	.nla_policy		= ipv6_nla_policy,
#endif
#ifdef CONFIG_SYSCTL
	.ctl_table_path		= nf_net_netfilter_sysctl_path,
	.ctl_table		= nf_ct_ipv6_sysctl_table,
#endif
	.me			= THIS_MODULE,
};

MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET6));
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI <yasuyuki.kozakai@toshiba.co.jp>");

static int __init nf_conntrack_l3proto_ipv6_init(void)
{
	int ret = 0;

	need_conntrack();

	ret = nf_ct_frag6_init();
	if (ret < 0) {
		printk("nf_conntrack_ipv6: can't initialize frag6.\n");
		return ret;
	}
	ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp6);
	if (ret < 0) {
		printk("nf_conntrack_ipv6: can't register tcp.\n");
		goto cleanup_frag6;
	}

	ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp6);
	if (ret < 0) {
		printk("nf_conntrack_ipv6: can't register udp.\n");
		goto cleanup_tcp;
	}

	ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_icmpv6);
	if (ret < 0) {
		printk("nf_conntrack_ipv6: can't register icmpv6.\n");
		goto cleanup_udp;
	}

	ret = nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv6);
	if (ret < 0) {
		printk("nf_conntrack_ipv6: can't register ipv6\n");
		goto cleanup_icmpv6;
	}

	ret = nf_register_hooks(ipv6_conntrack_ops,
				ARRAY_SIZE(ipv6_conntrack_ops));
	if (ret < 0) {
		printk("nf_conntrack_ipv6: can't register pre-routing defrag "
		       "hook.\n");
		goto cleanup_ipv6;
	}
	return ret;

 cleanup_ipv6:
	nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6);
 cleanup_icmpv6:
	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
 cleanup_udp:
	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6);
 cleanup_tcp:
	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
 cleanup_frag6:
	nf_ct_frag6_cleanup();
	return ret;
}

static void __exit nf_conntrack_l3proto_ipv6_fini(void)
{
	synchronize_net();
	nf_unregister_hooks(ipv6_conntrack_ops, ARRAY_SIZE(ipv6_conntrack_ops));
	nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6);
	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6);
	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
	nf_ct_frag6_cleanup();
}

module_init(nf_conntrack_l3proto_ipv6_init);
module_exit(nf_conntrack_l3proto_ipv6_fini);
Commit	Line	Data
	1	/*
	2	* Copyright (C)2004 USAGI/WIDE Project
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License version 2 as
	6	* published by the Free Software Foundation.
	7	*
	8	* Author:
	9	* Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
	10	*/
	11
	12	#include <linux/types.h>
	13	#include <linux/ipv6.h>
	14	#include <linux/in6.h>
	15	#include <linux/netfilter.h>
	16	#include <linux/module.h>
	17	#include <linux/skbuff.h>
	18	#include <linux/icmp.h>
	19	#include <linux/sysctl.h>
	20	#include <net/ipv6.h>
	21	#include <net/inet_frag.h>
	22
	23	#include <linux/netfilter_ipv6.h>
	24	#include <net/netfilter/nf_conntrack.h>
	25	#include <net/netfilter/nf_conntrack_helper.h>
	26	#include <net/netfilter/nf_conntrack_l4proto.h>
	27	#include <net/netfilter/nf_conntrack_l3proto.h>
	28	#include <net/netfilter/nf_conntrack_core.h>
	29	#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
	30	#include <net/netfilter/nf_log.h>
	31
	32	static bool ipv6_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
	33	struct nf_conntrack_tuple *tuple)
	34	{
	35	const u_int32_t *ap;
	36	u_int32_t _addrs[8];
	37
	38	ap = skb_header_pointer(skb, nhoff + offsetof(struct ipv6hdr, saddr),
	39	sizeof(_addrs), _addrs);
	40	if (ap == NULL)
	41	return false;
	42
	43	memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6));
	44	memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6));
	45
	46	return true;
	47	}
	48
	49	static bool ipv6_invert_tuple(struct nf_conntrack_tuple *tuple,
	50	const struct nf_conntrack_tuple *orig)
	51	{
	52	memcpy(tuple->src.u3.ip6, orig->dst.u3.ip6, sizeof(tuple->src.u3.ip6));
	53	memcpy(tuple->dst.u3.ip6, orig->src.u3.ip6, sizeof(tuple->dst.u3.ip6));
	54
	55	return true;
	56	}
	57
	58	static int ipv6_print_tuple(struct seq_file *s,
	59	const struct nf_conntrack_tuple *tuple)
	60	{
	61	return seq_printf(s, "src=%pI6 dst=%pI6 ",
	62	tuple->src.u3.ip6, tuple->dst.u3.ip6);
	63	}
	64
	65	/*
	66	* Based on ipv6_skip_exthdr() in net/ipv6/exthdr.c
	67	*
	68	* This function parses (probably truncated) exthdr set "hdr"
	69	* of length "len". "nexthdrp" initially points to some place,
	70	* where type of the first header can be found.
	71	*
	72	* It skips all well-known exthdrs, and returns pointer to the start
	73	* of unparsable area i.e. the first header with unknown type.
	74	* if success, *nexthdr is updated by type/protocol of this header.
	75	*
	76	* NOTES: - it may return pointer pointing beyond end of packet,
	77	* if the last recognized header is truncated in the middle.
	78	* - if packet is truncated, so that all parsed headers are skipped,
	79	* it returns -1.
	80	* - if packet is fragmented, return pointer of the fragment header.
	81	* - ESP is unparsable for now and considered like
	82	* normal payload protocol.
	83	* - Note also special handling of AUTH header. Thanks to IPsec wizards.
	84	*/
	85
	86	static int nf_ct_ipv6_skip_exthdr(const struct sk_buff *skb, int start,
	87	u8 *nexthdrp, int len)
	88	{
	89	u8 nexthdr = *nexthdrp;
	90
	91	while (ipv6_ext_hdr(nexthdr)) {
	92	struct ipv6_opt_hdr hdr;
	93	int hdrlen;
	94
	95	if (len < (int)sizeof(struct ipv6_opt_hdr))
	96	return -1;
	97	if (nexthdr == NEXTHDR_NONE)
	98	break;
	99	if (nexthdr == NEXTHDR_FRAGMENT)
	100	break;
	101	if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
	102	BUG();
	103	if (nexthdr == NEXTHDR_AUTH)
	104	hdrlen = (hdr.hdrlen+2)<<2;
	105	else
	106	hdrlen = ipv6_optlen(&hdr);
	107
	108	nexthdr = hdr.nexthdr;
	109	len -= hdrlen;
	110	start += hdrlen;
	111	}
	112
	113	*nexthdrp = nexthdr;
	114	return start;
	115	}
	116
	117	static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff,
	118	unsigned int dataoff, u_int8_t protonum)
	119	{
	120	unsigned int extoff = nhoff + sizeof(struct ipv6hdr);
	121	unsigned char pnum;
	122	int protoff;
	123
	124	if (skb_copy_bits(skb, nhoff + offsetof(struct ipv6hdr, nexthdr),
	125	&pnum, sizeof(pnum)) != 0) {
	126	pr_debug("ip6_conntrack_core: can't get nexthdr\n");
	127	return -NF_ACCEPT;
	128	}
	129	protoff = nf_ct_ipv6_skip_exthdr(skb, extoff, &pnum, skb->len - extoff);
	130	/*
	131	* (protoff == skb->len) mean that the packet doesn't have no data
	132	* except of IPv6 & ext headers. but it's tracked anyway. - YK
	133	*/
	134	if ((protoff < 0) \|\| (protoff > skb->len)) {
	135	pr_debug("ip6_conntrack_core: can't find proto in pkt\n");
	136	return -NF_ACCEPT;
	137	}
	138
	139	*dataoff = protoff;
	140	*protonum = pnum;
	141	return NF_ACCEPT;
	142	}
	143
	144	static unsigned int ipv6_confirm(unsigned int hooknum,
	145	struct sk_buff *skb,
	146	const struct net_device *in,
	147	const struct net_device *out,
	148	int (okfn)(struct sk_buff ))
	149	{
	150	struct nf_conn *ct;
	151	const struct nf_conn_help *help;
	152	const struct nf_conntrack_helper *helper;
	153	enum ip_conntrack_info ctinfo;
	154	unsigned int ret, protoff;
	155	unsigned int extoff = (u8 *)(ipv6_hdr(skb) + 1) - skb->data;
	156	unsigned char pnum = ipv6_hdr(skb)->nexthdr;
	157
	158
	159	/* This is where we call the helper: as the packet goes out. */
	160	ct = nf_ct_get(skb, &ctinfo);
	161	if (!ct \|\| ctinfo == IP_CT_RELATED + IP_CT_IS_REPLY)
	162	goto out;
	163
	164	help = nfct_help(ct);
	165	if (!help)
	166	goto out;
	167	/* rcu_read_lock()ed by nf_hook_slow */
	168	helper = rcu_dereference(help->helper);
	169	if (!helper)
	170	goto out;
	171
	172	protoff = nf_ct_ipv6_skip_exthdr(skb, extoff, &pnum,
	173	skb->len - extoff);
	174	if (protoff > skb->len \|\| pnum == NEXTHDR_FRAGMENT) {
	175	pr_debug("proto header not found\n");
	176	return NF_ACCEPT;
	177	}
	178
	179	ret = helper->help(skb, protoff, ct, ctinfo);
	180	if (ret != NF_ACCEPT) {
	181	nf_log_packet(NFPROTO_IPV6, hooknum, skb, in, out, NULL,
	182	"nf_ct_%s: dropping packet", helper->name);
	183	return ret;
	184	}
	185	out:
	186	/* We've seen it coming out the other side: confirm it */
	187	return nf_conntrack_confirm(skb);
	188	}
	189
	190	static enum ip6_defrag_users nf_ct6_defrag_user(unsigned int hooknum,
	191	struct sk_buff *skb)
	192	{
	193	if (hooknum == NF_INET_PRE_ROUTING)
	194	return IP6_DEFRAG_CONNTRACK_IN;
	195	else
	196	return IP6_DEFRAG_CONNTRACK_OUT;
	197
	198	}
	199
	200	static unsigned int ipv6_defrag(unsigned int hooknum,
	201	struct sk_buff *skb,
	202	const struct net_device *in,
	203	const struct net_device *out,
	204	int (okfn)(struct sk_buff ))
	205	{
	206	struct sk_buff *reasm;
	207
	208	/* Previously seen (loopback)? */
	209	if (skb->nfct)
	210	return NF_ACCEPT;
	211
	212	reasm = nf_ct_frag6_gather(skb, nf_ct6_defrag_user(hooknum, skb));
	213	/* queued */
	214	if (reasm == NULL)
	215	return NF_STOLEN;
	216
	217	/* error occured or not fragmented */
	218	if (reasm == skb)
	219	return NF_ACCEPT;
	220
	221	nf_ct_frag6_output(hooknum, reasm, (struct net_device *)in,
	222	(struct net_device *)out, okfn);
	223
	224	return NF_STOLEN;
	225	}
	226
	227	static unsigned int __ipv6_conntrack_in(struct net *net,
	228	unsigned int hooknum,
	229	struct sk_buff *skb,
	230	int (okfn)(struct sk_buff ))
	231	{
	232	struct sk_buff *reasm = skb->nfct_reasm;
	233
	234	/* This packet is fragmented and has reassembled packet. */
	235	if (reasm) {
	236	/* Reassembled packet isn't parsed yet ? */
	237	if (!reasm->nfct) {
	238	unsigned int ret;
	239
	240	ret = nf_conntrack_in(net, PF_INET6, hooknum, reasm);
	241	if (ret != NF_ACCEPT)
	242	return ret;
	243	}
	244	nf_conntrack_get(reasm->nfct);
	245	skb->nfct = reasm->nfct;
	246	skb->nfctinfo = reasm->nfctinfo;
	247	return NF_ACCEPT;
	248	}
	249
	250	return nf_conntrack_in(net, PF_INET6, hooknum, skb);
	251	}
	252
	253	static unsigned int ipv6_conntrack_in(unsigned int hooknum,
	254	struct sk_buff *skb,
	255	const struct net_device *in,
	256	const struct net_device *out,
	257	int (okfn)(struct sk_buff ))
	258	{
	259	return __ipv6_conntrack_in(dev_net(in), hooknum, skb, okfn);
	260	}
	261
	262	static unsigned int ipv6_conntrack_local(unsigned int hooknum,
	263	struct sk_buff *skb,
	264	const struct net_device *in,
	265	const struct net_device *out,
	266	int (okfn)(struct sk_buff ))
	267	{
	268	/* root is playing with raw sockets. */
	269	if (skb->len < sizeof(struct ipv6hdr)) {
	270	if (net_ratelimit())
	271	printk("ipv6_conntrack_local: packet too short\n");
	272	return NF_ACCEPT;
	273	}
	274	return __ipv6_conntrack_in(dev_net(out), hooknum, skb, okfn);
	275	}
	276
	277	static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = {
	278	{
	279	.hook = ipv6_defrag,
	280	.owner = THIS_MODULE,
	281	.pf = NFPROTO_IPV6,
	282	.hooknum = NF_INET_PRE_ROUTING,
	283	.priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
	284	},
	285	{
	286	.hook = ipv6_conntrack_in,
	287	.owner = THIS_MODULE,
	288	.pf = NFPROTO_IPV6,
	289	.hooknum = NF_INET_PRE_ROUTING,
	290	.priority = NF_IP6_PRI_CONNTRACK,
	291	},
	292	{
	293	.hook = ipv6_conntrack_local,
	294	.owner = THIS_MODULE,
	295	.pf = NFPROTO_IPV6,
	296	.hooknum = NF_INET_LOCAL_OUT,
	297	.priority = NF_IP6_PRI_CONNTRACK,
	298	},
	299	{
	300	.hook = ipv6_defrag,
	301	.owner = THIS_MODULE,
	302	.pf = NFPROTO_IPV6,
	303	.hooknum = NF_INET_LOCAL_OUT,
	304	.priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
	305	},
	306	{
	307	.hook = ipv6_confirm,
	308	.owner = THIS_MODULE,
	309	.pf = NFPROTO_IPV6,
	310	.hooknum = NF_INET_POST_ROUTING,
	311	.priority = NF_IP6_PRI_LAST,
	312	},
	313	{
	314	.hook = ipv6_confirm,
	315	.owner = THIS_MODULE,
	316	.pf = NFPROTO_IPV6,
	317	.hooknum = NF_INET_LOCAL_IN,
	318	.priority = NF_IP6_PRI_LAST-1,
	319	},
	320	};
	321
	322	#if defined(CONFIG_NF_CT_NETLINK) \|\| defined(CONFIG_NF_CT_NETLINK_MODULE)
	323
	324	#include <linux/netfilter/nfnetlink.h>
	325	#include <linux/netfilter/nfnetlink_conntrack.h>
	326
	327	static int ipv6_tuple_to_nlattr(struct sk_buff *skb,
	328	const struct nf_conntrack_tuple *tuple)
	329	{
	330	NLA_PUT(skb, CTA_IP_V6_SRC, sizeof(u_int32_t) * 4,
	331	&tuple->src.u3.ip6);
	332	NLA_PUT(skb, CTA_IP_V6_DST, sizeof(u_int32_t) * 4,
	333	&tuple->dst.u3.ip6);
	334	return 0;
	335
	336	nla_put_failure:
	337	return -1;
	338	}
	339
	340	static const struct nla_policy ipv6_nla_policy[CTA_IP_MAX+1] = {
	341	[CTA_IP_V6_SRC] = { .len = sizeof(u_int32_t)*4 },
	342	[CTA_IP_V6_DST] = { .len = sizeof(u_int32_t)*4 },
	343	};
	344
	345	static int ipv6_nlattr_to_tuple(struct nlattr *tb[],
	346	struct nf_conntrack_tuple *t)
	347	{
	348	if (!tb[CTA_IP_V6_SRC] \|\| !tb[CTA_IP_V6_DST])
	349	return -EINVAL;
	350
	351	memcpy(&t->src.u3.ip6, nla_data(tb[CTA_IP_V6_SRC]),
	352	sizeof(u_int32_t) * 4);
	353	memcpy(&t->dst.u3.ip6, nla_data(tb[CTA_IP_V6_DST]),
	354	sizeof(u_int32_t) * 4);
	355
	356	return 0;
	357	}
	358
	359	static int ipv6_nlattr_tuple_size(void)
	360	{
	361	return nla_policy_len(ipv6_nla_policy, CTA_IP_MAX + 1);
	362	}
	363	#endif
	364
	365	struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 __read_mostly = {
	366	.l3proto = PF_INET6,
	367	.name = "ipv6",
	368	.pkt_to_tuple = ipv6_pkt_to_tuple,
	369	.invert_tuple = ipv6_invert_tuple,
	370	.print_tuple = ipv6_print_tuple,
	371	.get_l4proto = ipv6_get_l4proto,
	372	#if defined(CONFIG_NF_CT_NETLINK) \|\| defined(CONFIG_NF_CT_NETLINK_MODULE)
	373	.tuple_to_nlattr = ipv6_tuple_to_nlattr,
	374	.nlattr_tuple_size = ipv6_nlattr_tuple_size,
	375	.nlattr_to_tuple = ipv6_nlattr_to_tuple,
	376	.nla_policy = ipv6_nla_policy,
	377	#endif
	378	#ifdef CONFIG_SYSCTL
	379	.ctl_table_path = nf_net_netfilter_sysctl_path,
	380	.ctl_table = nf_ct_ipv6_sysctl_table,
	381	#endif
	382	.me = THIS_MODULE,
	383	};
	384
	385	MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET6));
	386	MODULE_LICENSE("GPL");
	387	MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI <yasuyuki.kozakai@toshiba.co.jp>");
	388
	389	static int __init nf_conntrack_l3proto_ipv6_init(void)
	390	{
	391	int ret = 0;
	392
	393	need_conntrack();
	394
	395	ret = nf_ct_frag6_init();
	396	if (ret < 0) {
	397	printk("nf_conntrack_ipv6: can't initialize frag6.\n");
	398	return ret;
	399	}
	400	ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_tcp6);
	401	if (ret < 0) {
	402	printk("nf_conntrack_ipv6: can't register tcp.\n");
	403	goto cleanup_frag6;
	404	}
	405
	406	ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udp6);
	407	if (ret < 0) {
	408	printk("nf_conntrack_ipv6: can't register udp.\n");
	409	goto cleanup_tcp;
	410	}
	411
	412	ret = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_icmpv6);
	413	if (ret < 0) {
	414	printk("nf_conntrack_ipv6: can't register icmpv6.\n");
	415	goto cleanup_udp;
	416	}
	417
	418	ret = nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv6);
	419	if (ret < 0) {
	420	printk("nf_conntrack_ipv6: can't register ipv6\n");
	421	goto cleanup_icmpv6;
	422	}
	423
	424	ret = nf_register_hooks(ipv6_conntrack_ops,
	425	ARRAY_SIZE(ipv6_conntrack_ops));
	426	if (ret < 0) {
	427	printk("nf_conntrack_ipv6: can't register pre-routing defrag "
	428	"hook.\n");
	429	goto cleanup_ipv6;
	430	}
	431	return ret;
	432
	433	cleanup_ipv6:
	434	nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6);
	435	cleanup_icmpv6:
	436	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
	437	cleanup_udp:
	438	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6);
	439	cleanup_tcp:
	440	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
	441	cleanup_frag6:
	442	nf_ct_frag6_cleanup();
	443	return ret;
	444	}
	445
	446	static void __exit nf_conntrack_l3proto_ipv6_fini(void)
	447	{
	448	synchronize_net();
	449	nf_unregister_hooks(ipv6_conntrack_ops, ARRAY_SIZE(ipv6_conntrack_ops));
	450	nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6);
	451	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_icmpv6);
	452	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udp6);
	453	nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_tcp6);
	454	nf_ct_frag6_cleanup();
	455	}
	456
	457	module_init(nf_conntrack_l3proto_ipv6_init);
	458	module_exit(nf_conntrack_l3proto_ipv6_fini);