net/netfilter/nf_conntrack_proto_icmp.c - pub/scm/linux/kernel/git/mraynal/linux - Git at Google

 /* (C) 1999-2001 Paul `Rusty' Russell
  * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
  * (C) 2006-2010 Patrick McHardy <kaber@trash.net>
  *
  * 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_conntrack_timeout.h>
 #include <net/netfilter/nf_conntrack_zones.h>
 #include <net/netfilter/nf_log.h>

 static const unsigned int nf_ct_icmp_timeout = 30*HZ;

 bool icmp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
 		       struct net *net, 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
 };

 bool nf_conntrack_invert_icmp_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;
 }

 /* Returns verdict for packet, or -1 for invalid. */
 int nf_conntrack_icmp_packet(struct nf_conn *ct,
 			     struct sk_buff *skb,
 			     enum ip_conntrack_info ctinfo,
 			     const struct nf_hook_state *state)
 {
 	/* 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. */
 	unsigned int *timeout = nf_ct_timeout_lookup(ct);
 	static const u_int8_t valid_new[] = {
 		[ICMP_ECHO] = 1,
 		[ICMP_TIMESTAMP] = 1,
 		[ICMP_INFO_REQUEST] = 1,
 		[ICMP_ADDRESS] = 1
 	};

 	if (state->pf != NFPROTO_IPV4)
 		return -NF_ACCEPT;

 	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 -NF_ACCEPT;
 	}

 	if (!timeout)
 		timeout = &nf_icmp_pernet(nf_ct_net(ct))->timeout;

 	nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
 	return NF_ACCEPT;
 }

 /* Returns conntrack if it dealt with ICMP, and filled in skb fields */
 static int
 icmp_error_message(struct nf_conn *tmpl, struct sk_buff *skb,
 		   const struct nf_hook_state *state)
 {
 	struct nf_conntrack_tuple innertuple, origtuple;
 	const struct nf_conntrack_tuple_hash *h;
 	const struct nf_conntrack_zone *zone;
 	enum ip_conntrack_info ctinfo;
 	struct nf_conntrack_zone tmp;

 	WARN_ON(skb_nfct(skb));
 	zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);

 	/* 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, state->net, &origtuple)) {
 		pr_debug("icmp_error_message: failed to get tuple\n");
 		return -NF_ACCEPT;
 	}

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

 	ctinfo = IP_CT_RELATED;

 	h = nf_conntrack_find_get(state->net, zone, &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 */
 	nf_ct_set(skb, nf_ct_tuplehash_to_ctrack(h), ctinfo);
 	return NF_ACCEPT;
 }

 static void icmp_error_log(const struct sk_buff *skb,
 			   const struct nf_hook_state *state,
 			   const char *msg)
 {
 	nf_l4proto_log_invalid(skb, state->net, state->pf,
 			       IPPROTO_ICMP, "%s", msg);
 }

 /* Small and modified version of icmp_rcv */
 int nf_conntrack_icmpv4_error(struct nf_conn *tmpl,
 			      struct sk_buff *skb, unsigned int dataoff,
 			      const struct nf_hook_state *state)
 {
 	const struct icmphdr *icmph;
 	struct icmphdr _ih;

 	/* Not enough header? */
 	icmph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_ih), &_ih);
 	if (icmph == NULL) {
 		icmp_error_log(skb, state, "short packet");
 		return -NF_ACCEPT;
 	}

 	/* See ip_conntrack_proto_tcp.c */
 	if (state->net->ct.sysctl_checksum &&
 	    state->hook == NF_INET_PRE_ROUTING &&
 	    nf_ip_checksum(skb, state->hook, dataoff, 0)) {
 		icmp_error_log(skb, state, "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) {
 		icmp_error_log(skb, state, "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(tmpl, skb, state);
 }

 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)

 #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)
 {
 	if (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))
 		goto nla_put_failure;
 	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 unsigned int icmp_nlattr_tuple_size(void)
 {
 	static unsigned int size __read_mostly;

 	if (!size)
 		size = nla_policy_len(icmp_nla_policy, CTA_PROTO_MAX + 1);

 	return size;
 }
 #endif

 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT

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

 static int icmp_timeout_nlattr_to_obj(struct nlattr *tb[],
 				      struct net *net, void *data)
 {
 	unsigned int *timeout = data;
 	struct nf_icmp_net *in = nf_icmp_pernet(net);

 	if (tb[CTA_TIMEOUT_ICMP_TIMEOUT]) {
 		if (!timeout)
 			timeout = &in->timeout;
 		*timeout =
 			ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMP_TIMEOUT])) * HZ;
 	} else if (timeout) {
 		/* Set default ICMP timeout. */
 		*timeout = in->timeout;
 	}
 	return 0;
 }

 static int
 icmp_timeout_obj_to_nlattr(struct sk_buff *skb, const void *data)
 {
 	const unsigned int *timeout = data;

 	if (nla_put_be32(skb, CTA_TIMEOUT_ICMP_TIMEOUT, htonl(*timeout / HZ)))
 		goto nla_put_failure;
 	return 0;

 nla_put_failure:
 	return -ENOSPC;
 }

 static const struct nla_policy
 icmp_timeout_nla_policy[CTA_TIMEOUT_ICMP_MAX+1] = {
 	[CTA_TIMEOUT_ICMP_TIMEOUT]	= { .type = NLA_U32 },
 };
 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */

 void nf_conntrack_icmp_init_net(struct net *net)
 {
 	struct nf_icmp_net *in = nf_icmp_pernet(net);

 	in->timeout = nf_ct_icmp_timeout;
 }

 const struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp =
 {
 	.l4proto		= IPPROTO_ICMP,
 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
 	.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_NF_CONNTRACK_TIMEOUT
 	.ctnl_timeout		= {
 		.nlattr_to_obj	= icmp_timeout_nlattr_to_obj,
 		.obj_to_nlattr	= icmp_timeout_obj_to_nlattr,
 		.nlattr_max	= CTA_TIMEOUT_ICMP_MAX,
 		.obj_size	= sizeof(unsigned int),
 		.nla_policy	= icmp_timeout_nla_policy,
 	},
 #endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
 };
	/* (C) 1999-2001 Paul `Rusty' Russell
	* (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
	* (C) 2006-2010 Patrick McHardy <kaber@trash.net>
	*
	* 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_conntrack_timeout.h>
	#include <net/netfilter/nf_conntrack_zones.h>
	#include <net/netfilter/nf_log.h>

	static const unsigned int nf_ct_icmp_timeout = 30*HZ;

	bool icmp_pkt_to_tuple(const struct sk_buff *skb, unsigned int dataoff,
	struct net net, 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
	};

	bool nf_conntrack_invert_icmp_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;
	}

	/* Returns verdict for packet, or -1 for invalid. */
	int nf_conntrack_icmp_packet(struct nf_conn *ct,
	struct sk_buff *skb,
	enum ip_conntrack_info ctinfo,
	const struct nf_hook_state *state)
	{
	/* 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. */
	unsigned int *timeout = nf_ct_timeout_lookup(ct);
	static const u_int8_t valid_new[] = {
	[ICMP_ECHO] = 1,
	[ICMP_TIMESTAMP] = 1,
	[ICMP_INFO_REQUEST] = 1,
	[ICMP_ADDRESS] = 1
	};

	if (state->pf != NFPROTO_IPV4)
	return -NF_ACCEPT;

	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 -NF_ACCEPT;
	}

	if (!timeout)
	timeout = &nf_icmp_pernet(nf_ct_net(ct))->timeout;

	nf_ct_refresh_acct(ct, ctinfo, skb, *timeout);
	return NF_ACCEPT;
	}

	/* Returns conntrack if it dealt with ICMP, and filled in skb fields */
	static int
	icmp_error_message(struct nf_conn tmpl, struct sk_buff skb,
	const struct nf_hook_state *state)
	{
	struct nf_conntrack_tuple innertuple, origtuple;
	const struct nf_conntrack_tuple_hash *h;
	const struct nf_conntrack_zone *zone;
	enum ip_conntrack_info ctinfo;
	struct nf_conntrack_zone tmp;

	WARN_ON(skb_nfct(skb));
	zone = nf_ct_zone_tmpl(tmpl, skb, &tmp);

	/* 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, state->net, &origtuple)) {
	pr_debug("icmp_error_message: failed to get tuple\n");
	return -NF_ACCEPT;
	}

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

	ctinfo = IP_CT_RELATED;

	h = nf_conntrack_find_get(state->net, zone, &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 */
	nf_ct_set(skb, nf_ct_tuplehash_to_ctrack(h), ctinfo);
	return NF_ACCEPT;
	}

	static void icmp_error_log(const struct sk_buff *skb,
	const struct nf_hook_state *state,
	const char *msg)
	{
	nf_l4proto_log_invalid(skb, state->net, state->pf,
	IPPROTO_ICMP, "%s", msg);
	}

	/* Small and modified version of icmp_rcv */
	int nf_conntrack_icmpv4_error(struct nf_conn *tmpl,
	struct sk_buff *skb, unsigned int dataoff,
	const struct nf_hook_state *state)
	{
	const struct icmphdr *icmph;
	struct icmphdr _ih;

	/* Not enough header? */
	icmph = skb_header_pointer(skb, ip_hdrlen(skb), sizeof(_ih), &_ih);
	if (icmph == NULL) {
	icmp_error_log(skb, state, "short packet");
	return -NF_ACCEPT;
	}

	/* See ip_conntrack_proto_tcp.c */
	if (state->net->ct.sysctl_checksum &&
	state->hook == NF_INET_PRE_ROUTING &&
	nf_ip_checksum(skb, state->hook, dataoff, 0)) {
	icmp_error_log(skb, state, "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) {
	icmp_error_log(skb, state, "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(tmpl, skb, state);
	}

	#if IS_ENABLED(CONFIG_NF_CT_NETLINK)

	#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)
	{
	if (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))
	goto nla_put_failure;
	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 unsigned int icmp_nlattr_tuple_size(void)
	{
	static unsigned int size __read_mostly;

	if (!size)
	size = nla_policy_len(icmp_nla_policy, CTA_PROTO_MAX + 1);

	return size;
	}
	#endif

	#ifdef CONFIG_NF_CONNTRACK_TIMEOUT

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

	static int icmp_timeout_nlattr_to_obj(struct nlattr *tb[],
	struct net net, void data)
	{
	unsigned int *timeout = data;
	struct nf_icmp_net *in = nf_icmp_pernet(net);

	if (tb[CTA_TIMEOUT_ICMP_TIMEOUT]) {
	if (!timeout)
	timeout = &in->timeout;
	*timeout =
	ntohl(nla_get_be32(tb[CTA_TIMEOUT_ICMP_TIMEOUT])) * HZ;
	} else if (timeout) {
	/* Set default ICMP timeout. */
	*timeout = in->timeout;
	}
	return 0;
	}

	static int
	icmp_timeout_obj_to_nlattr(struct sk_buff skb, const void data)
	{
	const unsigned int *timeout = data;

	if (nla_put_be32(skb, CTA_TIMEOUT_ICMP_TIMEOUT, htonl(*timeout / HZ)))
	goto nla_put_failure;
	return 0;

	nla_put_failure:
	return -ENOSPC;
	}

	static const struct nla_policy
	icmp_timeout_nla_policy[CTA_TIMEOUT_ICMP_MAX+1] = {
	[CTA_TIMEOUT_ICMP_TIMEOUT] = { .type = NLA_U32 },
	};
	#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */

	void nf_conntrack_icmp_init_net(struct net *net)
	{
	struct nf_icmp_net *in = nf_icmp_pernet(net);

	in->timeout = nf_ct_icmp_timeout;
	}

	const struct nf_conntrack_l4proto nf_conntrack_l4proto_icmp =
	{
	.l4proto = IPPROTO_ICMP,
	#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
	.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_NF_CONNTRACK_TIMEOUT
	.ctnl_timeout = {
	.nlattr_to_obj = icmp_timeout_nlattr_to_obj,
	.obj_to_nlattr = icmp_timeout_obj_to_nlattr,
	.nlattr_max = CTA_TIMEOUT_ICMP_MAX,
	.obj_size = sizeof(unsigned int),
	.nla_policy = icmp_timeout_nla_policy,
	},
	#endif /* CONFIG_NF_CONNTRACK_TIMEOUT */
	};