[net-next-2.6.git] / net / ipv4 / netfilter / nf_conntrack_proto_icmp.c

/* (C) 1999-2001 Paul `Rusty' Russell
 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
 *
 * 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.
 */

#include <linux/types.h>
#include <linux/timer.h>
#include <linux/netfilter.h>
#include <linux/in.h>
#include <linux/icmp.h>
#include <linux/seq_file.h>
#include <net/ip.h>
#include <net/checksum.h>
#include <linux/netfilter_ipv4.h>
#include <net/netfilter/nf_conntrack_tuple.h>
#include <net/netfilter/nf_conntrack_l4proto.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_log.h>

static unsigned int nf_ct_icmp_timeout __read_mostly = 30*HZ;

static bool icmp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
			      struct nf_conntrack_tuple *tuple)
{
	const struct icmphdr *hp;
	struct icmphdr _hdr;

	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
	if (hp == NULL)
		return false;

	tuple->dst.u.icmp.type = hp->type;
	tuple->src.u.icmp.id = hp->un.echo.id;
	tuple->dst.u.icmp.code = hp->code;

	return true;
}

/* Add 1; spaces filled with 0. */
static const u_int8_t invmap[] = {
	[ICMP_ECHO] = ICMP_ECHOREPLY + 1,
	[ICMP_ECHOREPLY] = ICMP_ECHO + 1,
	[ICMP_TIMESTAMP] = ICMP_TIMESTAMPREPLY + 1,
	[ICMP_TIMESTAMPREPLY] = ICMP_TIMESTAMP + 1,
	[ICMP_INFO_REQUEST] = ICMP_INFO_REPLY + 1,
	[ICMP_INFO_REPLY] = ICMP_INFO_REQUEST + 1,
	[ICMP_ADDRESS] = ICMP_ADDRESSREPLY + 1,
	[ICMP_ADDRESSREPLY] = ICMP_ADDRESS + 1
};

static bool icmp_invert_tuple(struct nf_conntrack_tuple *tuple,
			      const struct nf_conntrack_tuple *orig)
{
	if (orig->dst.u.icmp.type >= sizeof(invmap)
	    || !invmap[orig->dst.u.icmp.type])
		return false;

	tuple->src.u.icmp.id = orig->src.u.icmp.id;
	tuple->dst.u.icmp.type = invmap[orig->dst.u.icmp.type] - 1;
	tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
	return true;
}

/* Print out the per-protocol part of the tuple. */
static int icmp_print_tuple(struct seq_file *s,
			    const struct nf_conntrack_tuple *tuple)
{
	return seq_printf(s, "type=%u code=%u id=%u ",
			  tuple->dst.u.icmp.type,
			  tuple->dst.u.icmp.code,
			  ntohs(tuple->src.u.icmp.id));
}

/* Returns verdict for packet, or -1 for invalid. */
static int icmp_packet(struct nf_conn *ct,
		       const struct sk_buff *skb,
		       unsigned int dataoff,
		       enum ip_conntrack_info ctinfo,
		       u_int8_t pf,
		       unsigned int hooknum)
{
	/* Do not immediately delete the connection after the first
	   successful reply to avoid excessive conntrackd traffic
	   and also to handle correctly ICMP echo reply duplicates. */
	nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_icmp_timeout);

	return NF_ACCEPT;
}

/* Called when a new connection for this protocol found. */
static bool icmp_new(struct nf_conn *ct, const struct sk_buff *skb,
		     unsigned int dataoff)
{
	static const u_int8_t valid_new[] = {
		[ICMP_ECHO] = 1,
		[ICMP_TIMESTAMP] = 1,
		[ICMP_INFO_REQUEST] = 1,
		[ICMP_ADDRESS] = 1
	};

	if (ct->tuplehash[0].tuple.dst.u.icmp.type >= sizeof(valid_new)
	    || !valid_new[ct->tuplehash[0].tuple.dst.u.icmp.type]) {
		/* Can't create a new ICMP `conn' with this. */
		pr_debug("icmp: can't create new conn with type %u\n",
			 ct->tuplehash[0].tuple.dst.u.icmp.type);
		nf_ct_dump_tuple_ip(&ct->tuplehash[0].tuple);
		return false;
	}
	return true;
}

/* Returns conntrack if it dealt with ICMP, and filled in skb fields */
static int
icmp_error_message(struct net *net, struct sk_buff *skb,
		 enum ip_conntrack_info *ctinfo,
		 unsigned int hooknum)
{
	struct nf_conntrack_tuple innertuple, origtuple;
	const struct nf_conntrack_l4proto *innerproto;
	const struct nf_conntrack_tuple_hash *h;

	NF_CT_ASSERT(skb->nfct == NULL);

	/* Are they talking about one of our connections? */
	if (!nf_ct_get_tuplepr(skb,
			       skb_network_offset(skb) + ip_hdrlen(skb)
						       + sizeof(struct icmphdr),
			       PF_INET, &origtuple)) {
		pr_debug("icmp_error_message: failed to get tuple\n");
		return -NF_ACCEPT;
	}

	/* rcu_read_lock()ed by nf_hook_slow */
	innerproto = __nf_ct_l4proto_find(PF_INET, origtuple.dst.protonum);

	/* Ordinarily, we'd expect the inverted tupleproto, but it's
	   been preserved inside the ICMP. */
	if (!nf_ct_invert_tuple(&innertuple, &origtuple,
				&nf_conntrack_l3proto_ipv4, innerproto)) {
		pr_debug("icmp_error_message: no match\n");
		return -NF_ACCEPT;
	}

	*ctinfo = IP_CT_RELATED;

	h = nf_conntrack_find_get(net, &innertuple);
	if (!h) {
		pr_debug("icmp_error_message: no match\n");
		return -NF_ACCEPT;
	}

	if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
		*ctinfo += IP_CT_IS_REPLY;

	/* Update skb to refer to this connection */
	skb->nfct = &nf_ct_tuplehash_to_ctrack(h)->ct_general;
	skb->nfctinfo = *ctinfo;
	return -NF_ACCEPT;
}

/* Small and modified version of icmp_rcv */
static int
icmp_error(struct net *net, struct sk_buff *skb, unsigned int dataoff,
	   enum ip_conntrack_info *ctinfo, u_int8_t pf, unsigned int hooknum)
{
	const struct icmphdr *icmph;
	struct icmphdr _ih;

	/* Not enough header? */
	icmph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_ih), &_ih);
	if (icmph == NULL) {
		if (LOG_INVALID(net, IPPROTO_ICMP))
			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
				      "nf_ct_icmp: short packet ");
		return -NF_ACCEPT;
	}

	/* See ip_conntrack_proto_tcp.c */
	if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
	    nf_ip_checksum(skb, hooknum, dataoff, 0)) {
		if (LOG_INVALID(net, IPPROTO_ICMP))
			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
				      "nf_ct_icmp: bad HW ICMP checksum ");
		return -NF_ACCEPT;
	}

	/*
	 *	18 is the highest 'known' ICMP type. Anything else is a mystery
	 *
	 *	RFC 1122: 3.2.2  Unknown ICMP messages types MUST be silently
	 *		  discarded.
	 */
	if (icmph->type > NR_ICMP_TYPES) {
		if (LOG_INVALID(net, IPPROTO_ICMP))
			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
				      "nf_ct_icmp: invalid ICMP type ");
		return -NF_ACCEPT;
	}

	/* Need to track icmp error message? */
	if (icmph->type != ICMP_DEST_UNREACH
	    && icmph->type != ICMP_SOURCE_QUENCH
	    && icmph->type != ICMP_TIME_EXCEEDED
	    && icmph->type != ICMP_PARAMETERPROB
	    && icmph->type != ICMP_REDIRECT)
		return NF_ACCEPT;

	return icmp_error_message(net, skb, ctinfo, hooknum);
}

#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 icmp_tuple_to_nlattr(struct sk_buff *skb,
				const struct nf_conntrack_tuple *t)
{
	NLA_PUT_BE16(skb, CTA_PROTO_ICMP_ID, t->src.u.icmp.id);
	NLA_PUT_U8(skb, CTA_PROTO_ICMP_TYPE, t->dst.u.icmp.type);
	NLA_PUT_U8(skb, CTA_PROTO_ICMP_CODE, t->dst.u.icmp.code);

	return 0;

nla_put_failure:
	return -1;
}

static const struct nla_policy icmp_nla_policy[CTA_PROTO_MAX+1] = {
	[CTA_PROTO_ICMP_TYPE]	= { .type = NLA_U8 },
	[CTA_PROTO_ICMP_CODE]	= { .type = NLA_U8 },
	[CTA_PROTO_ICMP_ID]	= { .type = NLA_U16 },
};

static int icmp_nlattr_to_tuple(struct nlattr *tb[],
				struct nf_conntrack_tuple *tuple)
{
	if (!tb[CTA_PROTO_ICMP_TYPE]
	    || !tb[CTA_PROTO_ICMP_CODE]
	    || !tb[CTA_PROTO_ICMP_ID])
		return -EINVAL;

	tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMP_TYPE]);
	tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMP_CODE]);
	tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMP_ID]);

	if (tuple->dst.u.icmp.type >= sizeof(invmap)
	    || !invmap[tuple->dst.u.icmp.type])
		return -EINVAL;

	return 0;
}

static int icmp_nlattr_tuple_size(void)
{
	return nla_policy_len(icmp_nla_policy, CTA_PROTO_MAX + 1);
}
#endif

#ifdef CONFIG_SYSCTL
static struct ctl_table_header *icmp_sysctl_header;
static struct ctl_table icmp_sysctl_table[] = {
	{
		.procname	= "nf_conntrack_icmp_timeout",
		.data		= &nf_ct_icmp_timeout,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec_jiffies,
	},
	{ }
};
#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
static struct ctl_table icmp_compat_sysctl_table[] = {
	{
		.procname	= "ip_conntrack_icmp_timeout",
		.data		= &nf_ct_icmp_timeout,
		.maxlen		= sizeof(unsigned int),
		.mode		= 0644,
		.proc_handler	= proc_dointvec_jiffies,
	},
	{ }
};
#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
#endif /* CONFIG_SYSCTL */

struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp __read_mostly =
{
	.l3proto		= PF_INET,
	.l4proto		= IPPROTO_ICMP,
	.name			= "icmp",
	.pkt_to_tuple		= icmp_pkt_to_tuple,
	.invert_tuple		= icmp_invert_tuple,
	.print_tuple		= icmp_print_tuple,
	.packet			= icmp_packet,
	.new			= icmp_new,
	.error			= icmp_error,
	.destroy		= NULL,
	.me			= NULL,
#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
	.tuple_to_nlattr	= icmp_tuple_to_nlattr,
	.nlattr_tuple_size	= icmp_nlattr_tuple_size,
	.nlattr_to_tuple	= icmp_nlattr_to_tuple,
	.nla_policy		= icmp_nla_policy,
#endif
#ifdef CONFIG_SYSCTL
	.ctl_table_header	= &icmp_sysctl_header,
	.ctl_table		= icmp_sysctl_table,
#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
	.ctl_compat_table	= icmp_compat_sysctl_table,
#endif
#endif
};
Commit	Line	Data
	1	/* (C) 1999-2001 Paul `Rusty' Russell
	2	* (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
	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
	9	#include <linux/types.h>
	10	#include <linux/timer.h>
	11	#include <linux/netfilter.h>
	12	#include <linux/in.h>
	13	#include <linux/icmp.h>
	14	#include <linux/seq_file.h>
	15	#include <net/ip.h>
	16	#include <net/checksum.h>
	17	#include <linux/netfilter_ipv4.h>
	18	#include <net/netfilter/nf_conntrack_tuple.h>
	19	#include <net/netfilter/nf_conntrack_l4proto.h>
	20	#include <net/netfilter/nf_conntrack_core.h>
	21	#include <net/netfilter/nf_log.h>
	22
	23	static unsigned int nf_ct_icmp_timeout __read_mostly = 30*HZ;
	24
	25	static bool icmp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
	26	struct nf_conntrack_tuple *tuple)
	27	{
	28	const struct icmphdr *hp;
	29	struct icmphdr _hdr;
	30
	31	hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr);
	32	if (hp == NULL)
	33	return false;
	34
	35	tuple->dst.u.icmp.type = hp->type;
	36	tuple->src.u.icmp.id = hp->un.echo.id;
	37	tuple->dst.u.icmp.code = hp->code;
	38
	39	return true;
	40	}
	41
	42	/* Add 1; spaces filled with 0. */
	43	static const u_int8_t invmap[] = {
	44	[ICMP_ECHO] = ICMP_ECHOREPLY + 1,
	45	[ICMP_ECHOREPLY] = ICMP_ECHO + 1,
	46	[ICMP_TIMESTAMP] = ICMP_TIMESTAMPREPLY + 1,
	47	[ICMP_TIMESTAMPREPLY] = ICMP_TIMESTAMP + 1,
	48	[ICMP_INFO_REQUEST] = ICMP_INFO_REPLY + 1,
	49	[ICMP_INFO_REPLY] = ICMP_INFO_REQUEST + 1,
	50	[ICMP_ADDRESS] = ICMP_ADDRESSREPLY + 1,
	51	[ICMP_ADDRESSREPLY] = ICMP_ADDRESS + 1
	52	};
	53
	54	static bool icmp_invert_tuple(struct nf_conntrack_tuple *tuple,
	55	const struct nf_conntrack_tuple *orig)
	56	{
	57	if (orig->dst.u.icmp.type >= sizeof(invmap)
	58	\|\| !invmap[orig->dst.u.icmp.type])
	59	return false;
	60
	61	tuple->src.u.icmp.id = orig->src.u.icmp.id;
	62	tuple->dst.u.icmp.type = invmap[orig->dst.u.icmp.type] - 1;
	63	tuple->dst.u.icmp.code = orig->dst.u.icmp.code;
	64	return true;
	65	}
	66
	67	/* Print out the per-protocol part of the tuple. */
	68	static int icmp_print_tuple(struct seq_file *s,
	69	const struct nf_conntrack_tuple *tuple)
	70	{
	71	return seq_printf(s, "type=%u code=%u id=%u ",
	72	tuple->dst.u.icmp.type,
	73	tuple->dst.u.icmp.code,
	74	ntohs(tuple->src.u.icmp.id));
	75	}
	76
	77	/* Returns verdict for packet, or -1 for invalid. */
	78	static int icmp_packet(struct nf_conn *ct,
	79	const struct sk_buff *skb,
	80	unsigned int dataoff,
	81	enum ip_conntrack_info ctinfo,
	82	u_int8_t pf,
	83	unsigned int hooknum)
	84	{
	85	/* Do not immediately delete the connection after the first
	86	successful reply to avoid excessive conntrackd traffic
	87	and also to handle correctly ICMP echo reply duplicates. */
	88	nf_ct_refresh_acct(ct, ctinfo, skb, nf_ct_icmp_timeout);
	89
	90	return NF_ACCEPT;
	91	}
	92
	93	/* Called when a new connection for this protocol found. */
	94	static bool icmp_new(struct nf_conn ct, const struct sk_buff skb,
	95	unsigned int dataoff)
	96	{
	97	static const u_int8_t valid_new[] = {
	98	[ICMP_ECHO] = 1,
	99	[ICMP_TIMESTAMP] = 1,
	100	[ICMP_INFO_REQUEST] = 1,
	101	[ICMP_ADDRESS] = 1
	102	};
	103
	104	if (ct->tuplehash[0].tuple.dst.u.icmp.type >= sizeof(valid_new)
	105	\|\| !valid_new[ct->tuplehash[0].tuple.dst.u.icmp.type]) {
	106	/* Can't create a new ICMP `conn' with this. */
	107	pr_debug("icmp: can't create new conn with type %u\n",
	108	ct->tuplehash[0].tuple.dst.u.icmp.type);
	109	nf_ct_dump_tuple_ip(&ct->tuplehash[0].tuple);
	110	return false;
	111	}
	112	return true;
	113	}
	114
	115	/* Returns conntrack if it dealt with ICMP, and filled in skb fields */
	116	static int
	117	icmp_error_message(struct net net, struct sk_buff skb,
	118	enum ip_conntrack_info *ctinfo,
	119	unsigned int hooknum)
	120	{
	121	struct nf_conntrack_tuple innertuple, origtuple;
	122	const struct nf_conntrack_l4proto *innerproto;
	123	const struct nf_conntrack_tuple_hash *h;
	124
	125	NF_CT_ASSERT(skb->nfct == NULL);
	126
	127	/* Are they talking about one of our connections? */
	128	if (!nf_ct_get_tuplepr(skb,
	129	skb_network_offset(skb) + ip_hdrlen(skb)
	130	+ sizeof(struct icmphdr),
	131	PF_INET, &origtuple)) {
	132	pr_debug("icmp_error_message: failed to get tuple\n");
	133	return -NF_ACCEPT;
	134	}
	135
	136	/* rcu_read_lock()ed by nf_hook_slow */
	137	innerproto = __nf_ct_l4proto_find(PF_INET, origtuple.dst.protonum);
	138
	139	/* Ordinarily, we'd expect the inverted tupleproto, but it's
	140	been preserved inside the ICMP. */
	141	if (!nf_ct_invert_tuple(&innertuple, &origtuple,
	142	&nf_conntrack_l3proto_ipv4, innerproto)) {
	143	pr_debug("icmp_error_message: no match\n");
	144	return -NF_ACCEPT;
	145	}
	146
	147	*ctinfo = IP_CT_RELATED;
	148
	149	h = nf_conntrack_find_get(net, &innertuple);
	150	if (!h) {
	151	pr_debug("icmp_error_message: no match\n");
	152	return -NF_ACCEPT;
	153	}
	154
	155	if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
	156	*ctinfo += IP_CT_IS_REPLY;
	157
	158	/* Update skb to refer to this connection */
	159	skb->nfct = &nf_ct_tuplehash_to_ctrack(h)->ct_general;
	160	skb->nfctinfo = *ctinfo;
	161	return -NF_ACCEPT;
	162	}
	163
	164	/* Small and modified version of icmp_rcv */
	165	static int
	166	icmp_error(struct net net, struct sk_buff skb, unsigned int dataoff,
	167	enum ip_conntrack_info *ctinfo, u_int8_t pf, unsigned int hooknum)
	168	{
	169	const struct icmphdr *icmph;
	170	struct icmphdr _ih;
	171
	172	/* Not enough header? */
	173	icmph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_ih), &_ih);
	174	if (icmph == NULL) {
	175	if (LOG_INVALID(net, IPPROTO_ICMP))
	176	nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
	177	"nf_ct_icmp: short packet ");
	178	return -NF_ACCEPT;
	179	}
	180
	181	/* See ip_conntrack_proto_tcp.c */
	182	if (net->ct.sysctl_checksum && hooknum == NF_INET_PRE_ROUTING &&
	183	nf_ip_checksum(skb, hooknum, dataoff, 0)) {
	184	if (LOG_INVALID(net, IPPROTO_ICMP))
	185	nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
	186	"nf_ct_icmp: bad HW ICMP checksum ");
	187	return -NF_ACCEPT;
	188	}
	189
	190	/*
	191	* 18 is the highest 'known' ICMP type. Anything else is a mystery
	192	*
	193	* RFC 1122: 3.2.2 Unknown ICMP messages types MUST be silently
	194	* discarded.
	195	*/
	196	if (icmph->type > NR_ICMP_TYPES) {
	197	if (LOG_INVALID(net, IPPROTO_ICMP))
	198	nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,
	199	"nf_ct_icmp: invalid ICMP type ");
	200	return -NF_ACCEPT;
	201	}
	202
	203	/* Need to track icmp error message? */
	204	if (icmph->type != ICMP_DEST_UNREACH
	205	&& icmph->type != ICMP_SOURCE_QUENCH
	206	&& icmph->type != ICMP_TIME_EXCEEDED
	207	&& icmph->type != ICMP_PARAMETERPROB
	208	&& icmph->type != ICMP_REDIRECT)
	209	return NF_ACCEPT;
	210
	211	return icmp_error_message(net, skb, ctinfo, hooknum);
	212	}
	213
	214	#if defined(CONFIG_NF_CT_NETLINK) \|\| defined(CONFIG_NF_CT_NETLINK_MODULE)
	215
	216	#include <linux/netfilter/nfnetlink.h>
	217	#include <linux/netfilter/nfnetlink_conntrack.h>
	218
	219	static int icmp_tuple_to_nlattr(struct sk_buff *skb,
	220	const struct nf_conntrack_tuple *t)
	221	{
	222	NLA_PUT_BE16(skb, CTA_PROTO_ICMP_ID, t->src.u.icmp.id);
	223	NLA_PUT_U8(skb, CTA_PROTO_ICMP_TYPE, t->dst.u.icmp.type);
	224	NLA_PUT_U8(skb, CTA_PROTO_ICMP_CODE, t->dst.u.icmp.code);
	225
	226	return 0;
	227
	228	nla_put_failure:
	229	return -1;
	230	}
	231
	232	static const struct nla_policy icmp_nla_policy[CTA_PROTO_MAX+1] = {
	233	[CTA_PROTO_ICMP_TYPE] = { .type = NLA_U8 },
	234	[CTA_PROTO_ICMP_CODE] = { .type = NLA_U8 },
	235	[CTA_PROTO_ICMP_ID] = { .type = NLA_U16 },
	236	};
	237
	238	static int icmp_nlattr_to_tuple(struct nlattr *tb[],
	239	struct nf_conntrack_tuple *tuple)
	240	{
	241	if (!tb[CTA_PROTO_ICMP_TYPE]
	242	\|\| !tb[CTA_PROTO_ICMP_CODE]
	243	\|\| !tb[CTA_PROTO_ICMP_ID])
	244	return -EINVAL;
	245
	246	tuple->dst.u.icmp.type = nla_get_u8(tb[CTA_PROTO_ICMP_TYPE]);
	247	tuple->dst.u.icmp.code = nla_get_u8(tb[CTA_PROTO_ICMP_CODE]);
	248	tuple->src.u.icmp.id = nla_get_be16(tb[CTA_PROTO_ICMP_ID]);
	249
	250	if (tuple->dst.u.icmp.type >= sizeof(invmap)
	251	\|\| !invmap[tuple->dst.u.icmp.type])
	252	return -EINVAL;
	253
	254	return 0;
	255	}
	256
	257	static int icmp_nlattr_tuple_size(void)
	258	{
	259	return nla_policy_len(icmp_nla_policy, CTA_PROTO_MAX + 1);
	260	}
	261	#endif
	262
	263	#ifdef CONFIG_SYSCTL
	264	static struct ctl_table_header *icmp_sysctl_header;
	265	static struct ctl_table icmp_sysctl_table[] = {
	266	{
	267	.procname = "nf_conntrack_icmp_timeout",
	268	.data = &nf_ct_icmp_timeout,
	269	.maxlen = sizeof(unsigned int),
	270	.mode = 0644,
	271	.proc_handler = proc_dointvec_jiffies,
	272	},
	273	{ }
	274	};
	275	#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
	276	static struct ctl_table icmp_compat_sysctl_table[] = {
	277	{
	278	.procname = "ip_conntrack_icmp_timeout",
	279	.data = &nf_ct_icmp_timeout,
	280	.maxlen = sizeof(unsigned int),
	281	.mode = 0644,
	282	.proc_handler = proc_dointvec_jiffies,
	283	},
	284	{ }
	285	};
	286	#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
	287	#endif /* CONFIG_SYSCTL */
	288
	289	struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp __read_mostly =
	290	{
	291	.l3proto = PF_INET,
	292	.l4proto = IPPROTO_ICMP,
	293	.name = "icmp",
	294	.pkt_to_tuple = icmp_pkt_to_tuple,
	295	.invert_tuple = icmp_invert_tuple,
	296	.print_tuple = icmp_print_tuple,
	297	.packet = icmp_packet,
	298	.new = icmp_new,
	299	.error = icmp_error,
	300	.destroy = NULL,
	301	.me = NULL,
	302	#if defined(CONFIG_NF_CT_NETLINK) \|\| defined(CONFIG_NF_CT_NETLINK_MODULE)
	303	.tuple_to_nlattr = icmp_tuple_to_nlattr,
	304	.nlattr_tuple_size = icmp_nlattr_tuple_size,
	305	.nlattr_to_tuple = icmp_nlattr_to_tuple,
	306	.nla_policy = icmp_nla_policy,
	307	#endif
	308	#ifdef CONFIG_SYSCTL
	309	.ctl_table_header = &icmp_sysctl_header,
	310	.ctl_table = icmp_sysctl_table,
	311	#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
	312	.ctl_compat_table = icmp_compat_sysctl_table,
	313	#endif
	314	#endif
	315	};